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New research – atmospheric and oceanic circulation (October 27, 2016)

Posted by Ari Jokimäki on October 27, 2016

Some of the latest papers on atmospheric and oceanic circulation are shown below. First a few highlighted papers with abstracts and then a list of some other papers. If this subject interests you, be sure to check also the other papers – they are by no means less interesting than the highlighted ones.

Highlights

On the atmospheric response experiment to a Blue Arctic Ocean (Nakamura et al. 2016) http://onlinelibrary.wiley.com/doi/10.1002/2016GL070526/abstract

Abstract: We demonstrated atmospheric responses to a reduction in Arctic sea ice via simulations in which Arctic sea ice decreased stepwise from the present-day range to an ice-free range. In all cases, the tropospheric response exhibited a negative Arctic Oscillation (AO)-like pattern. An intensification of the climatological planetary-scale wave due to the present-day sea ice reduction on the Atlantic side of the Arctic Ocean induced stratospheric polar vortex weakening and the subsequent negative AO. Conversely, strong Arctic warming due to ice-free conditions across the entire Arctic Ocean induced a weakening of the tropospheric westerlies corresponding to a negative AO without troposphere-stratosphere coupling, for which the planetary-scale wave response to a surface heat source extending to the Pacific side of the Arctic Ocean was responsible. Because the resultant negative AO-like response was accompanied by secondary circulation in the meridional plane, atmospheric heat transport into the Arctic increased, accelerating the Arctic amplification.

Atlantic multi-decadal oscillation influence on weather regimes over Europe and the Mediterranean in spring and summer (Zampieri et al. 2016) http://www.sciencedirect.com/science/article/pii/S092181811630371X

Abstract: We analyze the influence of the Atlantic sea surface temperature multi-decadal variability on the day-by-day sequence of large-scale atmospheric circulation patterns (i.e. the “weather regimes”) over the Euro-Atlantic region. In particular, we examine of occurrence of weather regimes from 1871 to present. This analysis is conducted by applying a clustering technique on the daily mean sea level pressure field provided by the 20th Century Reanalysis project, which was successfully applied in other studies focused on the Atlantic Multi-decadal Oscillation (AMO). In spring and summer, results show significant changes in the frequencies of certain weather regimes associated with the phase shifts of the AMO. These changes are consistent with the seasonal surface pressure, precipitation, and temperature anomalies associated with the AMO shifts in Europe.

Ocean and atmosphere feedbacks affecting AMOC hysteresis in a GCM (Jackson et al. 2016) http://rd.springer.com/article/10.1007%2Fs00382-016-3336-8

Abstract: Theories suggest that the Atlantic Meridional Overturning Circulation (AMOC) can exhibit a hysteresis where, for a given input of fresh water into the north Atlantic, there are two possible states: one with a strong overturning in the north Atlantic (on) and the other with a reverse Atlantic cell (off). A previous study showed hysteresis of the AMOC for the first time in a coupled general circulation model (Hawkins et al. in Geophys Res Lett. doi:10.1029/2011GL047208, 2011). In this study we show that the hysteresis found by Hawkins et al. (2011) is sensitive to the method with which the fresh water input is compensated. If this compensation is applied throughout the volume of the global ocean, rather than at the surface, the region of hysteresis is narrower and the off states are very different: when the compensation is applied at the surface, a strong Pacific overturning cell and a strong Atlantic reverse cell develops; when the compensation is applied throughout the volume there is little change in the Pacific and only a weak Atlantic reverse cell develops. We investigate the mechanisms behind the transitions between the on and off states in the two experiments, and find that the difference in hysteresis is due to the different off states. We find that the development of the Pacific overturning cell results in greater atmospheric moisture transport into the North Atlantic, and also is likely responsible for a stronger Atlantic reverse cell. These both act to stabilize the off state of the Atlantic overturning.

Arctic amplification: does it impact the polar jet stream? (Meleshko et al. 2016) http://www.tellusa.net/index.php/tellusa/article/view/32330

Abstract: It has been hypothesised that the Arctic amplification of temperature changes causes a decrease in the northward temperature gradient in the troposphere, thereby enhancing the oscillation of planetary waves leading to extreme weather in mid-latitudes. To test this hypothesis, we study the response of the atmosphere to Arctic amplification for a projected summer sea-ice-free period using an atmospheric model with prescribed surface boundary conditions from a state-of-the-art Earth system model. Besides a standard global warming simulation, we also conducted a sensitivity experiment with sea ice and sea surface temperature anomalies in the Arctic. We show that when global climate warms, enhancement of the northward heat transport provides the major contribution to decrease the northward temperature gradient in the polar troposphere in cold seasons, causing more oscillation of the planetary waves. However, while Arctic amplification significantly enhances near-surface air temperature in the polar region, it is not large enough to invoke an increased oscillation of the planetary waves.

Skilful predictions of the winter North Atlantic Oscillation one year ahead (Dunstone et al. 2016) http://www.nature.com/ngeo/journal/vaop/ncurrent/full/ngeo2824.html

Abstract: The winter North Atlantic Oscillation is the primary mode of atmospheric variability in the North Atlantic region and has a profound influence on European and North American winter climate. Until recently, seasonal variability of the North Atlantic Oscillation was thought to be largely driven by chaotic and inherently unpredictable processes. However, latest generation seasonal forecasting systems have demonstrated significant skill in predicting the North Atlantic Oscillation when initialized a month before the onset of winter. Here we extend skilful dynamical model predictions to more than a year ahead. The skill increases greatly with ensemble size due to a spuriously small signal-to-noise ratio in the model, and consequently larger ensembles are projected to further increase the skill in predicting the North Atlantic Oscillation. We identify two sources of skill for second-winter forecasts of the North Atlantic Oscillation: climate variability in the tropical Pacific region and predictable effects of solar forcing on the stratospheric polar vortex strength. We also identify model biases in Arctic sea ice that, if reduced, may further increase skill. Our results open possibilities for a range of new climate services, including for the transport, energy, water management and insurance sectors.

Other papers

Narrowing of the ITCZ in a warming climate: physical mechanisms (Byrne & Schneider, 2016) http://onlinelibrary.wiley.com/doi/10.1002/2016GL070396/abstract

Observed and simulated fingerprints of multidecadal climate variability, and their contributions to periods of global SST stagnation (Barcikowska et al. 2016) http://journals.ametsoc.org/doi/abs/10.1175/JCLI-D-16-0443.1

Observed Changes in the Southern Hemispheric Circulation in May (Ivy et al. 2016) http://journals.ametsoc.org/doi/abs/10.1175/JCLI-D-16-0394.1

Annual Variations of the Tropopause Height over the Tibetan Plateau Compared with those over other regions (Yang et al. 2016) http://www.sciencedirect.com/science/article/pii/S0377026516300951

The influences of the Atlantic Multidecadal Oscillation on the Mean Strength of the North Pacific Subtropical High during Boreal Winter (Lyu et al. 2016) http://journals.ametsoc.org/doi/abs/10.1175/JCLI-D-16-0525.1

The Role of Tropical Inter-Basin SST Gradients in Forcing Walker Circulation Trends (Zhang & Karnauskas, 2016) http://journals.ametsoc.org/doi/abs/10.1175/JCLI-D-16-0349.1

The role of low-frequency variation in the manifestation of warming trend and ENSO amplitude (Yeo et al. 2016) http://rd.springer.com/article/10.1007%2Fs00382-016-3376-0

Changes in meandering of the Northern Hemisphere circulation (Di Capua & Coumou, 2016) http://iopscience.iop.org/article/10.1088/1748-9326/11/9/094028/meta

Direct observations of the Antarctic Slope Current transport at 113°E (Peña-Molino et al. 2016) http://onlinelibrary.wiley.com/doi/10.1002/2015JC011594/abstract

Accounting for Centennial Scale Variability when Detecting Changes in ENSO: a study of the Pliocene (Tindall et al. 2016) http://onlinelibrary.wiley.com/doi/10.1002/2016PA002951/abstract

The Quasi-Biennial Oscillation of 2015-16: Hiccup or Death Spiral? (Dunkerton, 2016) http://onlinelibrary.wiley.com/doi/10.1002/2016GL070921/abstract

The weakening of the ENSO–Indian Ocean Dipole (IOD) coupling strength in recent decades (Ham et al. 2016) http://rd.springer.com/article/10.1007%2Fs00382-016-3339-5

On the Recent Destabilization of the Gulf Stream Path downstream of Cape Hatteras (Andres, 2016) http://onlinelibrary.wiley.com/doi/10.1002/2016GL069966/abstract

The relationship between the Madden Julian Oscillation and the North Atlantic Oscillation (Jiang et al. 2016) http://onlinelibrary.wiley.com/doi/10.1002/qj.2917/abstract

Lessened response of boreal winter stratospheric polar vortex to El Niño in recent decades (Hu et al. 2016) http://rd.springer.com/article/10.1007%2Fs00382-016-3340-z

Warming and weakening trends of the Kuroshio during 1993-2013 (Wang et al. 2016) http://onlinelibrary.wiley.com/doi/10.1002/2016GL069432/abstract

Prolonged El Niño conditions in 2014–15 and the rapid intensification of Hurricane Patricia in the eastern Pacific (Foltz et al. 2016) http://onlinelibrary.wiley.com/doi/10.1002/2016GL070274/abstract

Connection between Anomalous Zonal Activities of the South Asian High and Eurasian Summer Climate Anomalies (Shi & Qian, 2016) http://journals.ametsoc.org/doi/abs/10.1175/JCLI-D-15-0823.1

Ranking the strongest ENSO events while incorporating SST uncertainty (Huang et al. 2016) http://onlinelibrary.wiley.com/doi/10.1002/2016GL070888/abstract

The influence of the Gulf Stream on wintertime European blocking (O’Reilly et al. 2016) http://link.springer.com/article/10.1007%2Fs00382-015-2919-0

Projected changes in atmospheric rivers affecting Europe in CMIP5 models (Ramos et al. 2016) http://onlinelibrary.wiley.com/doi/10.1002/2016GL070634/abstract

Hosed vs. unhosed: interruptions of the Atlantic Meridional Overturning Circulation in a global coupled model, with and without freshwater forcing (Brown & Galbraith, 2016) http://www.clim-past.net/12/1663/2016/

An Oceanic Heat Content Based Definition for the Pacific Decadal Oscillation (Kumar & Wen, 2016) http://journals.ametsoc.org/doi/abs/10.1175/MWR-D-16-0080.1

An investigation of the presence of atmospheric rivers over the North Pacific during planetary-scale wave life cycles and their role in Arctic warming (Baggett et al. 2016) http://journals.ametsoc.org/doi/abs/10.1175/JAS-D-16-0033.1

Alternative modelling approaches for the ENSO time series: persistence and seasonality (Gil-Alana, 2016) http://onlinelibrary.wiley.com/doi/10.1002/joc.4850/abstract

Changes in the width of the tropical belt due to simple radiative forcing changes in the GeoMIP simulations (Davis et al. 2016) http://www.atmos-chem-phys.net/16/10083/2016/

Atmospheric River Landfall-Latitude Changes in Future Climate Simulations (Shields & Kiehl, 2016) http://onlinelibrary.wiley.com/doi/10.1002/2016GL070470/abstract

Posted in Climate science, Global warming effects | Leave a Comment »

New research – past climate (October 14, 2016)

Posted by Ari Jokimäki on October 14, 2016

Some of the latest papers on past climate changes are shown below. First a few highlighted papers with abstracts and then a list of some other papers. If this subject interests you, be sure to check also the other papers – they are by no means less interesting than the highlighted ones.

Highlights

Proxy-based Northern Hemisphere temperature reconstruction for the mid-to-late Holocene (Pei et al. 2016) http://rd.springer.com/article/10.1007%2Fs00704-016-1932-5

Abstract: The observed late twentieth century warming must be assessed in relation to natural long-term variations of the climatic system. Here, we present a Northern Hemisphere (NH) temperature reconstruction for the mid-to-late Holocene of the past 6000 years, based on a synthesis of existing paleo-temperature proxies that are capable of revealing centennial-scale variability. This includes 56 published temperature records across the NH land areas, with a sampling resolution ranging from 1 to 100 years and a time span of at least 1000 years. The composite plus scale (CPS) method is adopted with spatial weighting to develop the NH temperature reconstruction. Our reconstruction reveals abrupt cold epochs that match well the Bond events during the past 6000 years. The study further reveals two prominent cycles in NH temperature: 1700–2000-year cycle during the mid-to-late Holocene and 1200–1500-year cycle during the past 3500 years. Our reconstruction indicates that the late twentieth century NH temperature and its rate of warming are both unprecedentedly high over the past 5000 years. By comparing our reconstruction with the projected temperature increase scenarios, we find that temperature by the end of the twenty-first century would likely exceed any peaks during the mid-to-late Holocene.

How warm was Greenland during the last interglacial period? (Landais et al. 2016) http://www.clim-past.net/12/1933/2016/

Abstract: The last interglacial period (LIG,~129–116 thousand years ago) provides the most recent case study of multimillennial polar warming above the preindustrial level and a response of the Greenland and Antarctic ice sheets to this warming, as well as a test bed for climate and ice sheet models. Past changes in Greenland ice sheet thickness and surface temperature during this period were recently derived from the North Greenland Eemian Ice Drilling (NEEM) ice core records, northwest Greenland. The NEEM paradox has emerged from an estimated large local warming above the preindustrial level (7.5 ± 1.8 °C at the deposition site 126 kyr ago without correction for any overall ice sheet altitude changes between the LIG and the preindustrial period) based on water isotopes, together with limited local ice thinning, suggesting more resilience of the real Greenland ice sheet than shown in some ice sheet models. Here, we provide an independent assessment of the average LIG Greenland surface warming using ice core air isotopic composition (δ15N) and relationships between accumulation rate and temperature. The LIG surface temperature at the upstream NEEM deposition site without ice sheet altitude correction is estimated to be warmer by +8.5 ± 2.5 °C compared to the preindustrial period. This temperature estimate is consistent with the 7.5 ± 1.8 °C warming initially determined from NEEM water isotopes but at the upper end of the preindustrial period to LIG temperature difference of +5.2 ± 2.3 °C obtained at the NGRIP (North Greenland Ice Core Project) site by the same method. Climate simulations performed with present-day ice sheet topography lead in general to a warming smaller than reconstructed, but sensitivity tests show that larger amplitudes (up to 5 °C) are produced in response to prescribed changes in sea ice extent and ice sheet topography.

Response of Central European SST to atmospheric pCO2 forcing during the Oligocene – A combined proxy data and numerical climate model approach (Walliser et al. 2016) http://www.sciencedirect.com/science/article/pii/S0031018216302887

Abstract: CO2-induced global warming will affect seasonal to decadal temperature patterns. Expected changes will be particularly strong in extratropical regions where temperatures will increase at faster rates than at lower latitudes. Despite that, it is still poorly constrained how precisely short-term climate dynamics will change in a generally warmer world, particularly in nearshore surface waters in the extratropics, i.e., the ecologically most productive regions of the ocean on which many human societies depend. Specifically, a detailed knowledge of the relationship between pCO2 and seasonal SST is crucial to understand interactions between the ocean and the atmosphere. In the present investigation, we have studied for the first time how rising atmospheric pCO2 levels forced surface temperature changes in Central Europe (paleolatitude ~ 45 °N) during the mid-Oligocene (from ca. 31 to 25 Ma), a time interval of Earth history during which global conditions were comparable to those predicted for the next few centuries. For this purpose, we computed numerical climate models for the Oligocene (winter, summer, annual average) assuming an atmospheric carbon dioxide rise from 400 to 560 ppm (current level to two times pre-industrial levels, PAL) and from 400 to 840 ppm (= three times PAL), respectively. These models were compared to seasonally resolved sea surface temperatures (SST) reconstructed from δ18O values of fossil bivalve shells (Glycymeris planicostalis, G. obovata, Palliolum pictum, Arctica islandica and Isognomon maxillata sandbergeri) and shark teeth (Carcharias cuspidata, C. acutissima and Physogaleus latus) collected from the shallow water deposits of the Mainz and Kassel Basins (Germany). Multi-taxon oxygen isotope-based reconstructions suggest a gradual rise of temperatures in surface waters (upper 30 to 40 m), on average, by as much as 4 °C during the Rupelian stage followed by a 4 °C cooling during the Chattian stage. Seasonal temperature amplitudes increased by ca. 2 °C during the warmest time interval of the Rupelian stage, with warming being more pronounced during summer (5 °C) than during winter (3 °C). According to numerical climate simulations, the warming of surface waters during the early Oligocene required a CO2 increase by at least 160 ppm, i.e., 400 ppm to 560 ppm. Given that atmospheric carbon dioxide levels predicted for the near future will likely exceed this value significantly, the Early Oligocene warming gives a hint of the possible future climate in Central Europe under elevated CO2 levels.

Low Florida coral calcification rates in the Plio-Pleistocene (Brachert et al. 2016) http://www.biogeosciences.net/13/4513/2016/

Abstract: In geological outcrops and drill cores from reef frameworks, the skeletons of scleractinian corals are usually leached and more or less completely transformed into sparry calcite because the highly porous skeletons formed of metastable aragonite (CaCO3) undergo rapid diagenetic alteration. Upon alteration, ghost structures of the distinct annual growth bands often allow for reconstructions of annual extension ( =  growth) rates, but information on skeletal density needed for reconstructions of calcification rates is invariably lost. This report presents the bulk density, extension rates and calcification rates of fossil reef corals which underwent minor diagenetic alteration only. The corals derive from unlithified shallow water carbonates of the Florida platform (south-eastern USA), which formed during four interglacial sea level highstands dated approximately 3.2, 2.9, 1.8, and 1.2 Ma in the mid-Pliocene to early Pleistocene. With regard to the preservation, the coral skeletons display smooth growth surfaces with minor volumes of marine aragonite cement within intra-skeletal porosity. Within the skeletal structures, voids are commonly present along centres of calcification which lack secondary cements. Mean extension rates were 0.44 ± 0.19 cm yr−1 (range 0.16 to 0.86 cm yr−1), mean bulk density was 0.96 ± 0.36 g cm−3 (range 0.55 to 1.83 g cm−3) and calcification rates ranged from 0.18 to 0.82 g cm−2 yr−1 (mean 0.38 ± 0.16 g cm−2 yr−1), values which are 50 % of modern shallow-water reef corals. To understand the possible mechanisms behind these low calcification rates, we compared the fossil calcification rates with those of modern zooxanthellate corals (z corals) from the Western Atlantic (WA) and Indo-Pacific calibrated against sea surface temperature (SST). In the fossil data, we found a widely analogous relationship with SST in z corals from the WA, i.e. density increases and extension rate decreases with increasing SST, but over a significantly larger temperature window during the Plio-Pleistocene. With regard to the environment of coral growth, stable isotope proxy data from the fossil corals and the overall structure of the ancient shallow marine communities are consistent with a well-mixed, open marine environment similar to the present-day Florida Reef Tract, but variably affected by intermittent upwelling. Upwelling along the platform may explain low rates of reef coral calcification and inorganic cementation, but is too localised to account also for low extension rates of Pliocene z corals throughout the tropical WA region. Low aragonite saturation on a more global scale in response to rapid glacial–interglacial CO2 cyclicity is also a potential factor, but Plio-Pleistocene atmospheric pCO2 is generally believed to have been broadly similar to the present day. Heat stress related to globally high interglacial SST only episodically moderated by intermittent upwelling affecting the Florida platform seems to be another likely reason for low calcification rates. From these observations we suggest some present coral reef systems to be endangered from future ocean warming.

The ‘Little Ice Age’ in the Himalaya: A review of glacier advance driven by Northern Hemisphere temperature change (Rowan, 2016) http://hol.sagepub.com/content/early/2016/08/08/0959683616658530.abstract

Abstract: Northern Hemisphere cooling between 1400 and 1900 in the Common Era (CE) resulted in the expansion of glaciers during a period known as the ‘Little Ice Age’ (LIA). Early investigation of recent advances of Himalayan glaciers assumed that these events were synchronous with LIA advances identified in Europe, based on the appearance and position of moraines and without numerical age control. However, applications of Quaternary dating techniques such as terrestrial cosmogenic nuclide dating have allowed researchers to determine numerical ages for these young moraines and clarify when glacial maxima occurred. This paper reviews geochronological evidence for the last advance of glaciers in the Himalaya. The 66 ages younger than 2000 years (0–2000 CE) calculated from 138 samples collected from glacial landforms demonstrate that peak moraine building occurred between 1300 and 1600 CE, slightly earlier than the coldest period of Northern Hemisphere air temperatures. The timing of LIA advances varied spatially, likely influenced by variations in topography and meteorology across and along the mountain range. Palaeoclimate proxies indicate cooling air temperatures from 1300 CE leading to a southward shift in the Asian monsoon, increased Westerly winter precipitation and generally wetter conditions across the range around 1400 and 1800 CE. The last advance of glaciers in the Himalaya during a period of variable climate resulted from cold Northern Hemisphere air temperatures and was sustained by increased snowfall as atmospheric circulation reorganised in response to cooling during the LIA.

Other papers

Dendroclimatology and historical climatology of Voronezh region, European Russia, since 1790s (Matskovsky et al. 2016) http://onlinelibrary.wiley.com/doi/10.1002/joc.4896/abstract

Can stable oxygen and hydrogen isotopes from Australian subfossil Chironomus head capsules be used as proxies for past temperature change? (Chang et al. 2016) http://rd.springer.com/article/10.1007%2Fs10933-016-9920-4

Global deep water circulation between 2.4 and 1.7 Ma and its connection to the onset of Northern Hemisphere Glaciation (Du et al. 2016) http://onlinelibrary.wiley.com/doi/10.1002/2015PA002906/abstract

Evidence of temperature and precipitation change over the past 100 years in a high-resolution pollen record from the boreal forest of Central European Russia (Olchev et al. 2016) http://hol.sagepub.com/content/early/2016/10/04/0959683616670472.abstract

The Bølling-age Blomvåg Beds, western Norway: implications for the Older Dryas glacial re-advance and the age of the deglaciation (Mangerud et al. 2016) http://onlinelibrary.wiley.com/doi/10.1111/bor.12208/abstract

Impact of meltwater on high-latitude early Last Interglacial climate (Stone et al. 2016) http://www.clim-past.net/12/1919/2016/

Late Miocene global cooling and the rise of modern ecosystems (Herbert et al. 2016) http://www.nature.com/ngeo/journal/vaop/ncurrent/full/ngeo2813.html

On the palaeoclimatic potential of a millennium-long oak ring width chronology from Slovakia (Prokop et al. 2016) http://www.sciencedirect.com/science/article/pii/S1125786516300893

A 414-year tree-ring-based April–July minimum temperature reconstruction and its implications for the extreme climate events, northeast China (Lyu et al. 2016) http://www.clim-past.net/12/1879/2016/

Interactions between climate change and human activities during the early to mid-Holocene in the eastern Mediterranean basins (Berger et al. 2016) http://www.clim-past.net/12/1847/2016/

The effect of greenhouse gas concentrations and ice sheets on the glacial AMOC in a coupled climate model (Klockmann et al. 2016) http://www.clim-past.net/12/1829/2016/

The MMCO-EOT conundrum: same benthic δ18O, different CO2 (Stap et al. 2016) http://onlinelibrary.wiley.com/doi/10.1002/2016PA002958/abstract

Bayesian hierarchical regression analysis of variations in sea surface temperature change over the past million years (Snyder, 2016) http://onlinelibrary.wiley.com/doi/10.1002/2016PA002944/abstract

Leaf margin analysis of Chinese woody plants and the constraints on its application to palaeoclimatic reconstruction (Li et al. 2016) http://onlinelibrary.wiley.com/doi/10.1111/geb.12498/abstract

The demise of the early Eocene greenhouse – Decoupled deep and surface water cooling in the eastern North Atlantic (Bornemann et al. 2016) http://www.sciencedirect.com/science/article/pii/S0921818116300054

Impact of ice sheet meltwater fluxes on the climate evolution at the onset of the Last Interglacial (Goelzer et al. 2016) http://www.clim-past.net/12/1721/2016/

The Response of Phanerozoic Surface Temperature to Variations in Atmospheric Oxygen Concentration (Payne et al. 2016) http://onlinelibrary.wiley.com/doi/10.1002/2016JD025459/abstract

Abrupt Bølling warming and ice saddle collapse contributions to the Meltwater Pulse 1a rapid sea level rise (Gregoire et al. 2016) http://onlinelibrary.wiley.com/doi/10.1002/2016GL070356/abstract

Early- to mid-Holocene forest-line and climate dynamics in southern Scandes mountains inferred from contrasting megafossil and pollen data (Paus & Haugland, 2016) http://hol.sagepub.com/content/early/2016/08/22/0959683616660172.abstract

Low frequency Pliocene climate variability in the eastern Nordic Seas (Risebrobakken et al. 2016) http://onlinelibrary.wiley.com/doi/10.1002/2015PA002918/abstract

Water and carbon stable isotope records from natural archives: a new database and interactive online platform for data browsing, visualizing and downloading (Bolliet et al. 2016) http://www.clim-past.net/12/1693/2016/

Diagenetic disturbances of marine sedimentary records from methane-influenced environments in the Fram Strait as indications of variation in seep intensity during the last 35 000 years (Sztybor & Rasmussen, 2016) http://onlinelibrary.wiley.com/doi/10.1111/bor.12202/abstract

Evidence of solar activity and El Niño signals in tree rings of Araucaria araucana and A. angustifolia in South America (Perone et al. 2016) http://www.sciencedirect.com/science/article/pii/S0921818115301077

Simulated response of the mid-Holocene Atlantic Meridional Overturning Circulation in ECHAM6-FESOM/MPIOM (Shi & Lohmann, 2016) http://onlinelibrary.wiley.com/doi/10.1002/2015JC011584/abstract

Holocene fire regimes and treeline migration rates in sub-arctic Canada (Sulphur et al. 2016) http://www.sciencedirect.com/science/article/pii/S0921818115300710

Hydroclimatic variability on the Indian-subcontinent in the past millennium: Review and assessment (Dixit & Tandon, 2016) http://www.sciencedirect.com/science/article/pii/S0012825216302136

Interglacial/glacial changes in coccolith-rich deposition in the SW Pacific Ocean: An analogue for a warmer world? (Duncan et al. 2016) http://www.sciencedirect.com/science/article/pii/S0921818115300783

Tibetan Plateau Geladaindong black carbon ice core record (1843‒1982): Recent increases due to higher emissions and lower snow accumulation (Jenkins et al. 2016) http://www.sciencedirect.com/science/article/pii/S1674927816300028

Posted in Climate science, Global warming effects | Leave a Comment »

New research – cryosphere (October 11, 2016)

Posted by Ari Jokimäki on October 11, 2016

Some of the latest papers on climate change impacts on cryosphere are shown below. First a few highlighted papers with abstracts and then a list of some other papers. If this subject interests you, be sure to check also the other papers – they are by no means less interesting than the highlighted ones.

Highlights

Grounding line retreat of Pope, Smith, and Kohler Glaciers, West Antarctica, measured with Sentinel-1a radar interferometry data (Scheuchl et al. 2016) http://onlinelibrary.wiley.com/doi/10.1002/2016GL069287/abstract

Abstract: We employ Sentinel-1a C band satellite radar interferometry data in Terrain Observation with Progressive Scans mode to map the grounding line and ice velocity of Pope, Smith, and Kohler glaciers, in West Antarctica, for the years 2014–2016 and compare the results with those obtained using Earth Remote Sensing Satellites (ERS-1/2) in 1992, 1996, and 2011. We observe an ongoing, rapid grounding line retreat of Smith at 2 km/yr (40 km since 1996), an 11 km retreat of Pope (0.5 km/yr), and a 2 km readvance of Kohler since 2011. The variability in glacier retreat is consistent with the distribution of basal slopes, i.e., fast along retrograde beds and slow along prograde beds. We find that several pinning points holding Dotson and Crosson ice shelves disappeared since 1996 due to ice shelf thinning, which signal the ongoing weakening of these ice shelves. Overall, the results indicate that ice shelf and glacier retreat in this sector remain unabated.

On the recent contribution of the Greenland ice sheet to sea level change (van den Broeke et al. 2016) http://www.the-cryosphere.net/10/1933/2016/

Abstract: We assess the recent contribution of the Greenland ice sheet (GrIS) to sea level change. We use the mass budget method, which quantifies ice sheet mass balance (MB) as the difference between surface mass balance (SMB) and solid ice discharge across the grounding line (D). A comparison with independent gravity change observations from GRACE shows good agreement for the overlapping period 2002–2015, giving confidence in the partitioning of recent GrIS mass changes. The estimated 1995 value of D and the 1958–1995 average value of SMB are similar at 411 and 418 Gt yr−1, respectively, suggesting that ice flow in the mid-1990s was well adjusted to the average annual mass input, reminiscent of an ice sheet in approximate balance. Starting in the early to mid-1990s, SMB decreased while D increased, leading to quasi-persistent negative MB. About 60 % of the associated mass loss since 1991 is caused by changes in SMB and the remainder by D. The decrease in SMB is fully driven by an increase in surface melt and subsequent meltwater runoff, which is slightly compensated by a small (< 3 %) increase in snowfall. The excess runoff originates from low-lying (< 2000 m a.s.l.) parts of the ice sheet; higher up, increased refreezing prevents runoff of meltwater from occurring, at the expense of increased firn temperatures and depleted pore space. With a 1991–2015 average annual mass loss of ~ 0.47 ± 0.23 mm sea level equivalent (SLE) and a peak contribution of 1.2 mm SLE in 2012, the GrIS has recently become a major source of global mean sea level rise.

Tropical Pacific SST drivers of recent Antarctic sea ice trends (Purich et al. 2016) http://journals.ametsoc.org/doi/abs/10.1175/JCLI-D-16-0440.1

Abstract: A strengthening of the Amundsen Sea Low from 1979-2013 has been shown to largely explain the observed increase in Antarctic sea ice concentration in the eastern Ross Sea and decrease in the Bellingshausen Sea. Here we show that while these changes are not generally seen in freely-running coupled climate model simulations, they are reproduced in simulations of two independent coupled climate models; one constrained by observed sea surface temperature anomalies in the tropical Pacific, and the other by observed surface wind-stress in the tropics. Our analysis confirms previous results and strengthens the conclusion that the phase change in the Interdecadal Pacific Oscillation from positive to negative over 1979-2013 contributed to the observed strengthening of the Amundsen Sea Low and associated pattern of Antarctic sea ice change during this period. New support for this conclusion is provided by simulated trends in spatial patterns of sea ice concentrations that are similar to those observed. Our results highlight the importance of accounting for teleconnections from low to high latitudes in both model simulations and observations of Antarctic sea ice variability and change.

Quantifying ice loss in the eastern Himalayas since 1974 using declassified spy satellite imagery (Maurer et al. 2016) http://www.the-cryosphere.net/10/2203/2016/

Abstract: Himalayan glaciers are important natural resources and climate indicators for densely populated regions in Asia. Remote sensing methods are vital for evaluating glacier response to changing climate over the vast and rugged Himalayan region, yet many platforms capable of glacier mass balance quantification are somewhat temporally limited due to typical glacier response times. We here rely on declassified spy satellite imagery and ASTER data to quantify surface lowering, ice volume change, and geodetic mass balance during 1974–2006 for glaciers in the eastern Himalayas, centered on the Bhutan–China border. The wide range of glacier types allows for the first mass balance comparison between clean, debris, and lake-terminating (calving) glaciers in the region. Measured glaciers show significant ice loss, with an estimated mean annual geodetic mass balance of −0.13 ± 0.06 m w.e. yr−1 (meters of water equivalent per year) for 10 clean-ice glaciers, −0.19 ± 0.11 m w.e. yr−1 for 5 debris-covered glaciers, −0.28 ± 0.10 m w.e. yr−1 for 6 calving glaciers, and −0.17±0.05 m w.e. yr−1 for all glaciers combined. Contrasting hypsometries along with melt pond, ice cliff, and englacial conduit mechanisms result in statistically similar mass balance values for both clean-ice and debris-covered glacier groups. Calving glaciers comprise 18 % (66 km2) of the glacierized area yet have contributed 30 % (−0.7 km3) to the total ice volume loss, highlighting the growing relevance of proglacial lake formation and associated calving for the future ice mass budget of the Himalayas as the number and size of glacial lakes increase.

Quantifying the uncertainty in historical and future simulations of Northern Hemisphere spring snow cover (Thackeray et al. 2016) http://journals.ametsoc.org/doi/abs/10.1175/JCLI-D-16-0341.1

Abstract: Projections of 21st century Northern Hemisphere (NH) spring snow cover extent (SCE) from two climate model ensembles are analyzed to characterize their uncertainty. The Fifth Coupled Model Intercomparison Project (CMIP5) multi-model ensemble exhibits variability due to both model differences and internal climate variability, whereas spread generated from a Canadian Earth System Model large ensemble (CanESM-LE) experiment is solely due to internal variability. The analysis shows that simulated 1981-2010 spring SCE trends are slightly weaker than observed (using an ensemble of snow products). Spring SCE is projected to decrease by -3.7±1.1% decade-1 within the CMIP5 ensemble over the 21st century. SCE loss is projected to accelerate for all spring months over the 21st century, with the exception of June (because most snow in this month has melted by the latter half of the 21st century). For 30-year spring SCE trends over the 21st century, internal variability estimated from CanESM-LE is substantial, but smaller than inter-model spread from CMIP5. Additionally, internal variability in NH extratropical land warming trends can affect SCE trends in the near-future (R2 = 0.45), while variability in winter precipitation can also have a significant (but lesser) impact on SCE trends. On the other hand, a majority of the inter-model spread is driven by differences in simulated warming (dominant in March, April, May), and snow cover available for melt (dominant in June). The strong temperature/SCE linkage suggests that model uncertainty in projections of SCE could be potentially reduced through improved simulation of spring season warming over land.

Other papers

Persistent artifacts in the NSIDC ice motion dataset and their implications for analysis (Szanyi et al. 2016)
http://onlinelibrary.wiley.com/doi/10.1002/2016GL069799/abstract

Distributed ice thickness and glacier volume in southern South America (Carrivick et al. 2016) http://www.sciencedirect.com/science/article/pii/S0921818116301515

Century-scale perspectives on observed and simulated Southern Ocean sea ice trends from proxy reconstructions (Hobbs et al. 2016) http://onlinelibrary.wiley.com/doi/10.1002/2016JC012111/abstract

Identifying dynamically induced variability in glacier mass-balance records (Christian et al. 2016) http://journals.ametsoc.org/doi/abs/10.1175/JCLI-D-16-0128.1

Impacts of marine instability across the East Antarctic Ice Sheet on Southern Ocean dynamics (Phipps et al. 2016) http://www.the-cryosphere.net/10/2317/2016/

Effects of bryophyte and lichen cover on permafrost soil temperature at large scale (Porada et al. 2016) http://www.the-cryosphere.net/10/2291/2016/

Meltwater Pathways from Marine Terminating Glaciers of the Greenland Ice Sheet (Gillard et al. 2016) http://onlinelibrary.wiley.com/doi/10.1002/2016GL070969/abstract

Assimilation of surface velocities between 1996 and 2010 to constrain the form of the basal friction law under Pine Island Glacier (Gillet-Chaulet et al. 2016) http://onlinelibrary.wiley.com/doi/10.1002/2016GL069937/abstract

Linked trends in the south Pacific sea ice edge and Southern Oscillation Index (Kwok et al. 2016) http://onlinelibrary.wiley.com/doi/10.1002/2016GL070655/abstract

Greenland during the last interglacial: the relative importance of insolation and oceanic changes (Pedersen et al. 2016) http://www.clim-past.net/12/1907/2016/

The impact of melt ponds on summertime microwave brightness temperatures and sea-ice concentrations (Kern et al. 2016) http://www.the-cryosphere.net/10/2217/2016/

The EUMETSAT sea ice concentration climate data record (Tonboe et al. 2016) http://www.the-cryosphere.net/10/2275/2016/

Temperature reconstruction from the length fluctuations of small glaciers in the eastern Alps (northeastern Italy) (Zecchetto et al. 2016) http://link.springer.com/article/10.1007%2Fs00382-016-3347-5

Variability, trends, and predictability of seasonal sea ice retreat and advance in the Chukchi Sea (Serreze et al. 2016) http://onlinelibrary.wiley.com/doi/10.1002/2016JC011977/abstract

Producing cloud-free MODIS snow cover products with conditional probability interpolation and meteorological data (Dong & Menzel, 2016) http://www.sciencedirect.com/science/article/pii/S0034425716303625

ICESat laser altimetry over small mountain glaciers (Treichler & Kääb, 2016) http://www.the-cryosphere.net/10/2129/2016/

Heterogeneous glacier thinning patterns over the last 40 years in Langtang Himal, Nepal (Ragettli et al. 2016) http://www.the-cryosphere.net/10/2075/2016/

Arctic sea ice patterns driven by the Asian Summer Monsoon (Grunseich & Wang, 2016) http://journals.ametsoc.org/doi/abs/10.1175/JCLI-D-16-0207.1

Impact of climate warming on snow processes in ny-Ålesund, a polar maritime site at Svalbard (López-Moreno et al. 2016) http://www.sciencedirect.com/science/article/pii/S0921818116303903

Variations in ice velocities of Pine Island Glacier Ice Shelf evaluated using multispectral image matching of Landsat time series data (Han et al. 2016) http://www.sciencedirect.com/science/article/pii/S0034425716303443

Application of GRACE to the assessment of model-based estimates of monthly Greenland Ice Sheet mass balance (2003–2012) (Schlegel et al. 2016) http://www.the-cryosphere.net/10/1965/2016/

Near-real-time Arctic sea ice thickness and volume from CryoSat-2 (Tilling et al. 2016) http://www.the-cryosphere.net/10/2003/2016/

Potential for estimation of snow depth on Arctic sea ice from CryoSat-2 and SARAL/AltiKa missions (Guerreiro et al. 2016) http://www.sciencedirect.com/science/article/pii/S0034425716302711

Sliding of temperate basal ice on a rough, hard bed: creep mechanisms, pressure melting, and implications for ice streaming (Krabbendam, 2016) http://www.the-cryosphere.net/10/1915/2016/

Monte Carlo modelling projects the loss of most land-terminating glaciers on Svalbard in the 21st century under RCP 8.5 forcing (Möller et al. 2016) http://iopscience.iop.org/article/10.1088/1748-9326/11/9/094006/meta

North-east sector of the Greenland Ice Sheet to undergo the greatest inland expansion of supraglacial lakes during the 21st century (Ignéczi et al. 2016) http://onlinelibrary.wiley.com/doi/10.1002/2016GL070338/abstract

Posted in Climate science, Global warming effects | Leave a Comment »

New research – biosphere (October 10, 2016)

Posted by Ari Jokimäki on October 10, 2016

Some of the latest papers on climate change impacts on biosphere are shown below. First a few highlighted papers with abstracts and then a list of some other papers. If this subject interests you, be sure to check also the other papers – they are by no means less interesting than the highlighted ones.

Highlights

Population trends influence species ability to track climate change (Ralston et al. 2016) http://onlinelibrary.wiley.com/doi/10.1111/gcb.13478/abstract

Abstract: Shifts of distributions have been attributed to species tracking their fundamental climate niches through space. However, several studies have now demonstrated that niche tracking is imperfect, that species’ climate niches may vary with population trends, and that geographic distributions may lag behind rapid climate change. These reports of imperfect niche tracking imply shifts in species’ realized climate niches. We argue that quantifying climate niche shifts and analyzing them for a suite of species reveal general patterns of niche shifts and the factors affecting species’ ability to track climate change. We analyzed changes in realized climate niche between 1984 and 2012 for 46 species of North American birds in relation to population trends in an effort to determine whether species differ in the ability to track climate change and whether differences in niche tracking are related to population trends. We found that increasingly abundant species tended to show greater levels of niche expansion (climate space occupied in 2012 but not in 1980) compared to declining species. Declining species had significantly greater niche unfilling (climate space occupied in 1980 but not in 2012) compared to increasing species due to an inability to colonize new sites beyond their range peripheries after climate had changed at sites of occurrence. Increasing species, conversely, were better able to colonize new sites and therefore showed very little niche unfilling. Our results indicate that species with increasing trends are better able to geographically track climate change compared to declining species, which exhibited lags relative to changes in climate. These findings have important implications for understanding past changes in distribution, as well as modeling dynamic species distributions in the face of climate change.

Phylogenetic conservatism and climate factors shape flowering phenology in alpine meadows (Li et al. 2016) http://rd.springer.com/article/10.1007%2Fs00442-016-3666-6

Abstract: The study of phylogenetic conservatism in alpine plant phenology is critical for predicting climate change impacts; currently we have a poor understanding of how phylogeny and climate factors interactively influence plant phenology. Therefore, we explored the influence of phylogeny and climate factors on flowering phenology in alpine meadows. For two different types of alpine plant communities, we recorded phenological data, including flowering peak, first flower budding, first flowering, first fruiting and the flowering end for 62 species over the course of 5 years (2008–2012). From sequences in two plastid regions, we constructed phylogenetic trees. We used Blomberg’s K and Pagel’s lambda to assess the phylogenetic signal in phenological traits and species’ phenological responses to climate factors. We found a significant phylogenetic signal in the date of all reproductive phenological events and in species’ phenological responses to weekly day length and temperature. The number of species in flower was strongly associated with the weekly day lengths and followed by the weekly temperature prior to phenological activity. Based on phylogenetic eigenvector regression (PVR) analysis, we found a highly shared influence of phylogeny and climate factors on alpine species flowering phenology. Our results suggest the phylogenetic conservatism in both flowering and fruiting phenology may depend on the similarity of responses to external environmental cues among close relatives.

Sea-ice indicators of polar bear habitat (Stern & Laidre, 2016) http://www.the-cryosphere.net/10/2027/2016/

Abstract: Nineteen subpopulations of polar bears (Ursus maritimus) are found throughout the circumpolar Arctic, and in all regions they depend on sea ice as a platform for traveling, hunting, and breeding. Therefore polar bear phenology – the cycle of biological events – is linked to the timing of sea-ice retreat in spring and advance in fall. We analyzed the dates of sea-ice retreat and advance in all 19 polar bear subpopulation regions from 1979 to 2014, using daily sea-ice concentration data from satellite passive microwave instruments. We define the dates of sea-ice retreat and advance in a region as the dates when the area of sea ice drops below a certain threshold (retreat) on its way to the summer minimum or rises above the threshold (advance) on its way to the winter maximum. The threshold is chosen to be halfway between the historical (1979–2014) mean September and mean March sea-ice areas. In all 19 regions there is a trend toward earlier sea-ice retreat and later sea-ice advance. Trends generally range from −3 to −9 days decade−1 in spring and from +3 to +9 days decade−1 in fall, with larger trends in the Barents Sea and central Arctic Basin. The trends are not sensitive to the threshold. We also calculated the number of days per year that the sea-ice area exceeded the threshold (termed ice-covered days) and the average sea-ice concentration from 1 June through 31 October. The number of ice-covered days is declining in all regions at the rate of −7 to −19 days decade−1, with larger trends in the Barents Sea and central Arctic Basin. The June–October sea-ice concentration is declining in all regions at rates ranging from −1 to −9 percent decade−1. These sea-ice metrics (or indicators of habitat change) were designed to be useful for management agencies and for comparative purposes among subpopulations. We recommend that the National Climate Assessment include the timing of sea-ice retreat and advance in future reports.

Lagging behind: have we overlooked previous-year rainfall effects in annual grasslands? (Dudney et al. 2016) http://onlinelibrary.wiley.com/doi/10.1111/1365-2745.12671/abstract

Abstract: 1.Rainfall is a key determinant of production and composition in arid and semiarid systems. Long-term studies relating composition and water availability primarily focus on current-year precipitation patterns, though mounting evidence highlights the importance of previous-year rainfall particularly in grasslands dominated by perennial species. The extent to which lagged precipitation effects occur in annual grasslands, however, remains largely unexplored.

2.We pair a long-term study with two manipulative experiments to identify patterns and mechanisms of lagged precipitation effects in annual grasslands. The long-term study captured variation in functional group (exotic annual forbs and grasses) abundance and precipitation across eight years at three northern California grassland sites. We then tested whether lagged rainfall effects were created through seed production and litter (residual dry matter) by manipulating rainfall and litter, respectively.

3.Rainfall from the previous-year growing season (both seasonal and total rainfall) shifted functional group abundance. High lagged rainfall was associated with increased grass and decreased forb abundance the following year. Current-year seasonal rainfall also influenced species composition, with winter rain increasing forb and decreasing grass abundance. Lagged precipitation effects were generally stronger for forbs than for grasses. Our experimental studies provided evidence for two mechanisms that contributed to lagged effects in annual grasslands. Higher rainfall increased seed production for grasses, which translated to more germinable seed the following year. Higher rainfall also increased biomass production and residual dry matter, which benefited grasses and reduced forb abundance.

4.Synthesis. Our results highlight the importance of previous-year precipitation in structuring annual community composition and suggest two important biotic pathways, seed rain and RDM, that regulate lagged community responses to rainfall. Incorporating lagged effects into models of grassland diversity and productivity could improve predictions of climate change impacts in annual grasslands.

Effects of high latitude protected areas on bird communities under rapid climate change (Santangeli et al. 2016) http://onlinelibrary.wiley.com/doi/10.1111/gcb.13518/abstract

Abstract: Anthropogenic climate change is rapidly becoming one of the main threats to biodiversity, along with other threats triggered by human-driven land-use change. Species are already responding to climate change by shifting their distributions polewards. This shift may create a spatial mismatch between dynamic species distributions and static protected areas (PAs). As protected areas represent one of the main pillars for preserving biodiversity today and in the future, it is important to assess their contribution in sheltering the biodiversity communities they were designated to protect. A recent development to investigate climate-driven impacts on biological communities is represented by the community temperature index (CTI). CTI provides a measure of the relative temperature average of a community in a specific assemblage. CTI value will be higher for assemblages dominated by warm species compared to those dominated by cold-dwelling species. We here model changes in the CTI of Finnish bird assemblages, as well as changes in species densities, within and outside of PAs during the past four decades in a large boreal landscape under rapid change. We show that CTI has markedly increased over time across Finland, with this change being similar within and outside PAs and five to seven times slower than the temperature increase. Moreover, CTI has been constantly lower within than outside of PAs, and PAs still support communities which show colder thermal index than those outside of PAs in the 70s and 80s. This result can be explained by the higher relative density of northern species within PAs than outside. Overall, our results provide some, albeit inconclusive, evidence that PAs may play a role in supporting the community of northern species. Results also suggest that communities are however shifting rapidly, both inside and outside of PAs, highlighting the need for adjusting conservation measures before it’s too late.

Other papers

Impact of temperature and precipitation extremes on the flowering dates of four German wildlife shrub species (Siegmund et al. 2016) http://www.biogeosciences.net/13/5541/2016/

Cyanobacteria in aquaculture systems: linking the occurrence, abundance and toxicity with rising temperatures (Sinden & Sinang, 2016) http://rd.springer.com/article/10.1007%2Fs13762-016-1112-2

Under-ice habitats for Antarctic krill larvae: could less mean more under climate warming? (Melbourne-Thomas et al. 2016) http://onlinelibrary.wiley.com/doi/10.1002/2016GL070846/abstract

Responses of land evapotranspiration to Earth’s greening in CMIP5 Earth System Models (Zeng et al. 2016) http://iopscience.iop.org/article/10.1088/1748-9326/11/10/104006/meta

Impacts of droughts on the growth resilience of Northern Hemisphere forests (Gazol et al. 2016) http://onlinelibrary.wiley.com/doi/10.1111/geb.12526/abstract

Environmental status of the Gulf of California: A review of responses to climate change and climate variability (Páez-Osuna et al. 2016) http://www.sciencedirect.com/science/article/pii/S0012825216301416

High-resolution tide projections reveal extinction threshold in response to sea-level rise (Field et al. 2016) http://onlinelibrary.wiley.com/doi/10.1111/gcb.13519/abstract

Quantifying full phenological event distributions reveals simultaneous advances, temporal stability and delays in spring and autumn migration timing in long-distance migratory birds (Miles et al. 2016) http://onlinelibrary.wiley.com/doi/10.1111/gcb.13486/abstract

Can we predict ectotherm responses to climate change using thermal performance curves and body temperatures? (Sinclair et al. 2016) http://onlinelibrary.wiley.com/doi/10.1111/ele.12686/abstract

Ectomycorrhizal fungal response to warming is linked to poor host performance at the boreal-temperate ecotone (Fernandez et al. 2016) http://onlinelibrary.wiley.com/doi/10.1111/gcb.13510/abstract

Spatiotemporal variability of stone pine (Pinus pinea L.) growth response to climate across the Iberian Peninsula (Natalini et al. 2016) http://www.sciencedirect.com/science/article/pii/S1125786516300777

Nonlinear, interacting responses to climate limit grassland production under global change (Zhu et al. 2016) http://www.pnas.org/content/113/38/10589.short

An unprecedented coastwide toxic algal bloom linked to anomalous ocean conditions (McCabe et al. 2016) http://onlinelibrary.wiley.com/doi/10.1002/2016GL070023/abstract

Increased activity of lysozyme and complement system in Atlantic halibut exposed to elevated CO2 at six different temperatures (de Souza et al. 2016) http://www.sciencedirect.com/science/article/pii/S0141113616301696

Multisite analysis of land surface phenology in North American temperate and boreal deciduous forests from Landsat (Melaas et al. 2016) http://www.sciencedirect.com/science/article/pii/S0034425716303571

Responses of spring phenology in a fruit tree species (Pyrus sp. cv. Pingguoli) to the changes in surface air temperature in Northeast China (Shen & Kobayashi, 2016) http://onlinelibrary.wiley.com/doi/10.1002/joc.4877/abstract

Climate change impacts on net primary production (NPP) and export production (EP) regulated by increasing stratification and phytoplankton community structure in the CMIP5 models (Fu et al. 2016) http://www.biogeosciences.net/13/5151/2016/

Decreased photosynthesis and growth with reduced respiration in the model diatom Phaeodactylum tricornutum grown under elevated CO2 over 1800 generations (Li et al. 2016) http://onlinelibrary.wiley.com/doi/10.1111/gcb.13501/abstract

Where do they go? The effects of topography and habitat diversity on reducing climatic debt in birds (Gaüzère et al. 2016) http://onlinelibrary.wiley.com/doi/10.1111/gcb.13500/abstract

Precipitation, not air temperature, drives functional responses of trees in semi-arid ecosystems (Grossiord et al. 2016) http://onlinelibrary.wiley.com/doi/10.1111/1365-2745.12662/abstract

Relationships between individual-tree mortality and water-balance variables indicate positive trends in water stress-induced tree mortality across North America (Hember et al. 2016) http://onlinelibrary.wiley.com/doi/10.1111/gcb.13428/abstract

Disturbances catalyze the adaptation of forest ecosystems to changing climate conditions (Thom et al. 2016) http://onlinelibrary.wiley.com/doi/10.1111/gcb.13506/abstract

Extreme climatic events constrain space use and survival of a ground-nesting bird (Tanner et al. 2016) http://onlinelibrary.wiley.com/doi/10.1111/gcb.13505/abstract

Spatial and evolutionary parallelism between shade and drought tolerance explains the distributions of conifers in the conterminous United States (Rueda et al. 2016) http://onlinelibrary.wiley.com/doi/10.1111/geb.12511/abstract

Effects of climate change on the distribution of indigenous species in oceanic islands (Azores) (Ferreira et al. 2016) http://rd.springer.com/article/10.1007%2Fs10584-016-1754-6

Northern ragweed ecotypes flower earlier and longer in response to elevated CO2: what are you sneezing at? (Stinson et al. 2016) http://rd.springer.com/article/10.1007%2Fs00442-016-3670-x

Australian vegetation phenology: new insights from satellite remote sensing and digital repeat photography (Moore et al. 2016) http://www.biogeosciences.net/13/5085/2016/

Temporal variability in the thermal requirements for vegetation phenology on the Tibetan plateau and its implications for carbon dynamics (Jin et al. 2016) http://rd.springer.com/article/10.1007%2Fs10584-016-1736-8

Posted in Global warming effects | Leave a Comment »

New research – climate and mankind (October 6, 2016)

Posted by Ari Jokimäki on October 6, 2016

Some of the latest papers on climate change impacts on mankind are shown below. First a few highlighted papers with abstracts and then a list of some other papers. If this subject interests you, be sure to check also the other papers – they are by no means less interesting than the highlighted ones.

Highlights

The limits of poverty reduction in support of climate change adaptation (Nelson et al. 2016) http://iopscience.iop.org/article/10.1088/1748-9326/11/9/094011/meta

Abstract: The relationship between poverty and climate change vulnerability is complex and though not commensurate, the distinctions between the two are often blurred. There is widespread recognition of the need to better understand poverty-vulnerability dynamics in order to improve risk management and poverty reduction investments. This is challenging due to the latent nature of adaptive capacities, frequent lack of baseline data, and the need for high-resolution studies. Here we respond to these challenges by analyzing household-level data in Northeast Brazil to compare drought events 14 years apart. In the period between droughts, the government implemented an aggressive anti-poverty program that includes financial and human capital investments. Poverty declined significantly, but the expected reduction in vulnerability did not occur, in part because the households were not investing in risk management strategies. Our findings complement other research that shows that households make rational decisions that may not correspond with policymaker expectations. We emphasize the need for complementary investments to help channel increased household wealth into risk reduction, and to ensure that the public sector itself continues to prioritize the public functions of risk management, especially in areas where the social cost of climatic risk is high.

Perceptions of thermal comfort in heatwave and non-heatwave conditions in Melbourne, Australia (Lam et al. 2016) http://www.sciencedirect.com/science/article/pii/S2212095516300396

Abstract: Heatwaves can cause discomfort and illnesses due to heat stress. However, how people perceive thermal comfort and adapt to extreme heat conditions on heatwave days is uncertain. Most outdoor thermal comfort studies have been conducted under non-extreme conditions and very few during heatwaves. For those studies that encountered a heatwave, sample size tends to be small or modelling approaches were used to assess thermal comfort. It is important to understand people’s perceptions in relation to the physiological experience during extreme heat, as it would help practitioners apply the extreme heat range of thermal indices in outdoor settings. To understand people’s thermal perception and clothing behaviour during a heatwave, we combined meteorological measurements and thermal comfort surveys at two botanic gardens in Melbourne, Australia. The variations in respondents’ thermal comfort and clothing are assessed during heatwave and non-heatwave conditions, where temperatures during heatwave conditions exceeded 36°C. We observed that local visitors felt significantly hotter and wore less clothing for the same ranges of the Universal Thermal Climate Index (UTCI) during heatwave than non-heatwave conditions. Thus, we suggest that thermal expectation influences changes in thermal perceptions and clothing, even over the course of several days to a week.

How do we assess vulnerability to climate change in India? A systematic review of literature (Singh et al. 2016) http://rd.springer.com/article/10.1007%2Fs10113-016-1043-y

Abstract: In countries like India where multiple risks interact with socio-economic differences to create and sustain vulnerability, assessing the vulnerability of people, places, and systems to climate change is a critical tool to prioritise adaptation. In India, several vulnerability assessment tools have been designed spanning multiple disciplines, by multiple actors, and at multiple scales. However, their conceptual, methodological, and disciplinary underpinnings, and resulting implications on who is identified as vulnerable, have not been interrogated. Addressing this gap, we systematically review peer-reviewed publications (n = 78) and grey literature (n = 42) to characterise how vulnerability to climate change is assessed in India. We frame our enquiry against four questions: (1) How is vulnerability conceptualised (vulnerability of whom/what, vulnerability to what), (2) who assesses vulnerability, (3) how is vulnerability assessed (methodology, scale), and (4) what are the implications of methodology on outcomes of the assessment. Our findings emphasise that methods to assess vulnerability to climate change are embedded in the disciplinary traditions, methodological approaches, and often-unstated motivations of those designing the assessment. Further, while most assessments acknowledge the importance of scalar and temporal aspects of vulnerability, we find few examples of it being integrated in methodology. Such methodological myopia potentially overlooks how social differentiation, ecological shifts, and institutional dynamics construct and perpetuate vulnerability. Finally, we synthesise the strengths and weaknesses of current vulnerability assessment methods in India and identify a predominance of research in rural landscapes with a relatively lower coverage in urban and peri-urban settlements, which are key interfaces of transitions.

Drought effects on US maize and soybean production: spatiotemporal patterns and historical changes (Zipper et al. 2016) http://iopscience.iop.org/article/10.1088/1748-9326/11/9/094021/meta

Abstract: Maximizing agricultural production on existing cropland is one pillar of meeting future global food security needs. To close crop yield gaps, it is critical to understand how climate extremes such as drought impact yield. Here, we use gridded, daily meteorological data and county-level annual yield data to quantify meteorological drought sensitivity of US maize and soybean production from 1958 to 2007. Meteorological drought negatively affects crop yield over most US crop-producing areas, and yield is most sensitive to short-term (1–3 month) droughts during critical development periods from July to August. While meteorological drought is associated with 13% of overall yield variability, substantial spatial variability in drought effects and sensitivity exists, with central and southeastern US becoming increasingly sensitive to drought over time. Our study illustrates fine-scale spatiotemporal patterns of drought effects, highlighting where variability in crop production is most strongly associated with drought, and suggests that management strategies that buffer against short-term water stress may be most effective at sustaining long-term crop productivity.

Climate change discourse among Iranian farmers (Zobeidi et al. 2016) http://rd.springer.com/article/10.1007%2Fs10584-016-1741-y

Abstract: Climate change poses a severe threat to agriculture and rural populations around the world, with the potential to devastate lives and livelihoods. Farmers need to adapt their farming methods and land management decisions to reduce the negative consequences associated with climate change. Understanding farmers’ beliefs and perceptions regarding climate change is a good starting point for addressing current and future policy. As there is no one-size-fits-all strategy to promote adaptation, local adaptation-support strategies must be tailored to the particular needs and constraints of specific groups of farmers. To determine the policy implications of such strategies, a prudent and cost-effective approach is to categorize farmers into homogenous groupings using Q methodology to establish their perceptual frameworks with respect to climate change. Forty six farmers completed the Q sort procedure in this study. Data analysis identified that there are three different types of farmers’ attitudes to climate change: fatalism, support seekers, and technocrats. These findings are critical for decision makers to help them develop more appropriate adaptation strategies for the agricultural sector.

Other papers

Long-term trend analysis in climate variables and agricultural adaptation strategies to climate change in the Senegal River Basin (Djaman et al. 2016) http://onlinelibrary.wiley.com/doi/10.1002/joc.4885/abstract

The Evolution of Agricultural Drought Transition Periods in the United States Corn Belt (Schiraldi & Roundy, 2016) http://journals.ametsoc.org/doi/abs/10.1175/MWR-D-16-0225.1

Do Western and Eastern Europe have the same agricultural climate response? Taking adaptive capacity into account (Vanschoenwinkel et al. 2016) http://www.sciencedirect.com/science/article/pii/S0959378016302060

Patterns of crop cover under future climates (Porfirio et al. 2016) http://rd.springer.com/article/10.1007%2Fs13280-016-0818-1

Longitudinal assessment of climate vulnerability: a case study from the Canadian Arctic (Archer et al. 2016) http://rd.springer.com/article/10.1007%2Fs11625-016-0401-5

Effects of Rainfall on Vehicle Crashes in Six U.S. States (Black et al. 2016) http://journals.ametsoc.org/doi/abs/10.1175/WCAS-D-16-0035.1

The prevalence of heat-related cardiorespiratory symptoms: the vulnerable groups identified from the National FINRISK 2007 Study (Näyhä et al. 2016) http://rd.springer.com/article/10.1007%2Fs00484-016-1243-7

Trade agreements, labour mobility and climate change in the Pacific Islands (Weber, 2016) http://link.springer.com/article/10.1007%2Fs10113-016-1047-7

Atmospheric CO2 enrichment and drought stress modify root exudation of barley (Calvo et al. 2016) http://onlinelibrary.wiley.com/doi/10.1111/gcb.13503/abstract

Physical activity profile of 2014 FIFA World Cup players, with regard to different ranges of air temperature and relative humidity (Chmura et al. 2016) http://rd.springer.com/article/10.1007%2Fs00484-016-1245-5

Assessing climate change vulnerability in urban America: stakeholder-driven approaches (McCormick, 2016) http://rd.springer.com/article/10.1007%2Fs10584-016-1757-3

Spatio-temporal analyses of impacts of multiple climatic hazards in a savannah ecosystem of Ghana (Yiran et al. 2016) http://www.sciencedirect.com/science/article/pii/S2212096316300493

Health sector preparedness for adaptation planning in India (Dasgupta et al. 2016) http://rd.springer.com/article/10.1007%2Fs10584-016-1745-7

The effect of climate change on rural land cover patterns in the Central United States (Lant et al. 2016) http://rd.springer.com/article/10.1007%2Fs10584-016-1738-6

Intensity and economic loss assessment of the snow, low-temperature and frost disasters: a case study of Beijing City (Wang et al. 2016) http://rd.springer.com/article/10.1007%2Fs11069-016-2429-3

A good farmer pays attention to the weather (Morton et al. 2016) http://www.sciencedirect.com/science/article/pii/S2212096316300481

Responding to the Millennium drought: comparing domestic water cultures in three Australian cities (Lindsay et al. 2016) http://link.springer.com/article/10.1007%2Fs10113-016-1048-6

Assessing climate adaptation options and uncertainties for cereal systems in West Africa (Guan et al. 2016) http://www.sciencedirect.com/science/article/pii/S0168192316303471

Contract farming and the adoption of climate change coping and adaptation strategies in the northern region of Ghana (Azumah et al. 2016) http://link.springer.com/article/10.1007%2Fs10668-016-9854-z

Present and future assessment of growing degree days over selected Greek areas with different climate conditions (Paparrizos & Matzarakis, 2016) http://rd.springer.com/article/10.1007%2Fs00703-016-0475-8

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New research – hydrosphere (September 26, 2016)

Posted by Ari Jokimäki on September 26, 2016

Some of the latest papers on climate change impacts on hydrosphere are shown below. First a few highlighted papers with abstracts and then a list of some other papers. If this subject interests you, be sure to check also the other papers – they are by no means less interesting than the highlighted ones.

Highlights

Ocean acidification over the next three centuries using a simple global climate carbon-cycle model: projections and sensitivities (Hartin et al. 2016) http://www.biogeosciences.net/13/4329/2016/

Abstract: Continued oceanic uptake of anthropogenic CO2 is projected to significantly alter the chemistry of the upper oceans over the next three centuries, with potentially serious consequences for marine ecosystems. Relatively few models have the capability to make projections of ocean acidification, limiting our ability to assess the impacts and probabilities of ocean changes. In this study we examine the ability of Hector v1.1, a reduced-form global model, to project changes in the upper ocean carbonate system over the next three centuries, and quantify the model’s sensitivity to parametric inputs. Hector is run under prescribed emission pathways from the Representative Concentration Pathways (RCPs) and compared to both observations and a suite of Coupled Model Intercomparison (CMIP5) model outputs. Current observations confirm that ocean acidification is already taking place, and CMIP5 models project significant changes occurring to 2300. Hector is consistent with the observational record within both the high- (> 55°) and low-latitude oceans (< 55°). The model projects low-latitude surface ocean pH to decrease from preindustrial levels of 8.17 to 7.77 in 2100, and to 7.50 in 2300; aragonite saturation levels (ΩAr) decrease from 4.1 units to 2.2 in 2100 and 1.4 in 2300 under RCP 8.5. These magnitudes and trends of ocean acidification within Hector are largely consistent with the CMIP5 model outputs, although we identify some small biases within Hector’s carbonate system. Of the parameters tested, changes in [H+] are most sensitive to parameters that directly affect atmospheric CO2 concentrations – Q10 (terrestrial respiration temperature response) as well as changes in ocean circulation, while changes in ΩAr saturation levels are sensitive to changes in ocean salinity and Q10. We conclude that Hector is a robust tool well suited for rapid ocean acidification projections and sensitivity analyses, and it is capable of emulating both current observations and large-scale climate models under multiple emission pathways.

Anthropogenic and climate-driven water depletion in Asia (Yi et al. 2016) http://onlinelibrary.wiley.com/doi/10.1002/2016GL069985/abstract

Abstract: Anthropogenic depletion of terrestrial water storage (TWS) can be alleviated in wet years and intensified in dry years, and this wet/dry pattern spanning seasons to years is termed climate variability. However, the anthropogenic and climate-driven changes have not been isolated in previous studies; thus, the estimated trend of changes in TWS is strongly dependent on the study period. Here we try to remove the influence of climate variability from the estimation of the anthropogenic contribution, which is an indicator of the environmental burden and important for TWS projections. Toward this end, we propose a linear relationship between the variation in water storage and precipitation. Factors related to the sensitivity of water storage to precipitation are given to correct for the climate variability, and the anthropogenic depletion of terrestrial water and groundwater in Asia is estimated to be −187 ± 38 Gt/yr and −100 ± 47 Gt/yr, respectively.

Are long tide gauge records in the wrong place to measure global mean sea level rise? (Thompson et al. 2016) http://onlinelibrary.wiley.com/doi/10.1002/2016GL070552/abstract

Abstract: Ocean dynamics, land motion, and changes in Earth’s gravitational and rotational fields cause local sea level change to deviate from the rate of global mean sea level rise. Here, we use observations and simulations of spatial structure in sea level change to estimate the likelihood that these processes cause sea level trends in the longest and highest-quality tide gauge records to be systematically biased relative to the true global mean rate. The analyzed records have an average 20th century rate of approximately 1.6 mm/yr, but based on the locations of these gauges, we show the simple average underestimates the 20th century global mean rate by 0.1  ±  0.2 mm/yr. Given the distribution of potential sampling biases, we find < 1% probability that observed trends from the longest and highest-quality TG records are consistent with global mean rates less than 1.4 mm/yr.

Development of a 0.5 deg global monthly raining day product from 1901-2010 (Stillman & Zeng, 2016) http://onlinelibrary.wiley.com/doi/10.1002/2016GL070244/abstract

Abstract: While several long-term global datasets of monthly precipitation amount (P) are widely available, only the Climate Research Unit (CRU) provides long-term global monthly raining day number (N) data (i.e., daily precipitation frequency in a month), with P/N representing the daily precipitation intensity. However, because CRU N is based on a limited number of gauges, it is found to perform poorly over data sparse regions. By combining the CRU method with a short-term gauge-satellite merged global daily precipitation dataset (CMORPH) and a global long-term monthly precipitation dataset (GPCC) with far more gauges than used in CRU, a new 0.5 deg global N dataset from 1901-2010 is developed, which differs significantly from CRU N. Compared with three independent regional daily precipitation products over U.S., China, and South America based on much denser gauge networks than used in CRU, the new product shows significant improvement over CRU N.

Detection and delineation of glacial lakes and identification of potentially dangerous lakes of Dhauliganga basin in the Himalaya by remote sensing techniques (Jha & Khare, 2016) http://link.springer.com/article/10.1007%2Fs11069-016-2565-9

Abstract: Glaciers are retreating and thinning in the high altitude of the Himalayas due to global warming, causing into formation of numerous glacial lakes. It is necessary to monitor these glacial lakes consistently to save properties and lives downstream from probable disastrous glacial lake outburst flood. In this study, image processing software ArcGIS and ERDAS Imagine have been used to analyse multispectral image obtained by Earth resource satellite Landsat for delineating the glacial lakes with the help of image enhancement technique like NDWI. Landsat data since 1972 through 2013 have been used and maximum seven glacial lakes (L1–L7) have been detected and delineated in Dhauliganga catchment, they are situated above 4000 masl. The Glacial Lake L2 (Lat 30°26′45″E and Long 80°23′16″N) is the largest whose surface area was 132,300 m2 in Sept 2009, and L6 (Lat 30°23′27″E and Long 80°31′52″N) is highly unstable with variation rate −55 to +145 % with increasing trend. Additionally, glacial lakes L2 (Lat 30°26′45″E and Long 80°23′16″N) and L6 (Lat 30°23′27″E and Long 80°31′52″N) have been identified as potentially hazardous. These lakes may probably burst; as a result, huge reserve of water and debris may be released all on a sudden. This may transform into hazardous flash flood in downstream causing loss of lives, as well as the destruction of houses, bridges, fields, forests, hydropower stations, roads, etc. It is to note that Dhauliganga river considered in this study is a tributary of Kaliganga river, and should not be confused with its namesake the Dhauliganga river, which is a tributary of Alaknanda river.

Other papers

Extreme hydrological changes in the southwestern US drive reductions in water supply to Southern California by mid century (Pagán et al. 2016) http://iopscience.iop.org/article/10.1088/1748-9326/11/9/094026/meta

Regionalizing Africa: Patterns of Precipitation Variability in Observations and Global Climate Models (Badr et al. 2016) http://journals.ametsoc.org/doi/abs/10.1175/JCLI-D-16-0182.1

Evidencing decadal and interdecadal hydroclimatic variability over the Central Andes (Segura et al. 2016) http://iopscience.iop.org/article/10.1088/1748-9326/11/9/094016/meta

The uncertainties and causes of the recent changes in global evapotranspiration from 1982 to 2010 (Dong & Dai, 2016) http://link.springer.com/article/10.1007%2Fs00382-016-3342-x

Spatial pattern of reference evapotranspiration change and its temporal evolution over Southwest China (Sun et al. 2016) http://rd.springer.com/article/10.1007%2Fs00704-016-1930-7

Climate change in the Blue Nile Basin Ethiopia: implications for water resources and sediment transport (Wagena et al. 2016) http://rd.springer.com/article/10.1007%2Fs10584-016-1785-z

Rainfall in Qatar: Is it changing? (Mamoon & Rahman, 2016) http://link.springer.com/article/10.1007%2Fs11069-016-2576-6

Global Precipitation Measurement (GPM) Mission Products and Services at the NASA Goddard Earth Sciences (GES) Data and Information Services Center (DISC) (Liu et al. 2016) http://journals.ametsoc.org/doi/abs/10.1175/BAMS-D-16-0023.1

A multi-satellite climatology of clouds, radiation and precipitation in southern West Africa and comparison to climate models (Hill et al. 2016) http://onlinelibrary.wiley.com/doi/10.1002/2016JD025246/abstract

Detection, Attribution and Projection of Regional Rainfall Changes on (Multi-) Decadal Time Scales: A Focus on Southeastern South America (Zhang et al. 2016) http://journals.ametsoc.org/doi/abs/10.1175/JCLI-D-16-0287.1

Which weather systems are projected to cause future changes in mean and extreme precipitation in CMIP5 simulations? (Utsumi et al. 2016) http://onlinelibrary.wiley.com/doi/10.1002/2016JD024939/abstract

Out-phased decadal precipitation regime shift in China and the United States (Yang & Fu, 2016) http://rd.springer.com/article/10.1007%2Fs00704-016-1907-6

Forcing of recent decadal variability in the Equatorial and North Indian Ocean (Thompson et al. 2016) http://onlinelibrary.wiley.com/doi/10.1002/2016JC012132/abstract

Proxy-based reconstruction of surface water acidification and carbonate saturation of the Levant Sea during the Anthropocene (Bialik & Sisma-Ventura, 2016) http://www.sciencedirect.com/science/article/pii/S2213305416300881

Understanding decreases in land relative humidity with global warming: conceptual model and GCM simulations (Byrne & O’Gorman, 2016) http://journals.ametsoc.org/doi/abs/10.1175/JCLI-D-16-0351.1

Spatial trend analysis of Hawaiian rainfall from 1920 to 2012 (Frazier & Giambelluca, 2016) http://onlinelibrary.wiley.com/doi/10.1002/joc.4862/abstract

Mapping of West Siberian taiga wetland complexes using Landsat imagery: implications for methane emissions (Terentieva et al. 2016) http://www.biogeosciences.net/13/4615/2016/

Wind driven mixing at intermediate depths in an ice-free Arctic Ocean (Lincoln et al. 2016) http://onlinelibrary.wiley.com/doi/10.1002/2016GL070454/abstract

Seasonal Evolution of Supraglacial Lakes on an East Antarctic Outlet Glacier (Langley et al. 2016) http://onlinelibrary.wiley.com/doi/10.1002/2016GL069511/abstract

Temperature-salinity structure of the North Atlantic circulation and associated heat and freshwater transports (Xu et al. 2016) http://journals.ametsoc.org/doi/abs/10.1175/JCLI-D-15-0798.1

Eustatic and Relative Sea Level Changes (Rovere et al. 2016) http://rd.springer.com/article/10.1007%2Fs40641-016-0045-7

A mechanism for the response of the zonally asymmetric subtropical hydrologic cycle to global warming (Levine & Boos, 2016) http://journals.ametsoc.org/doi/abs/10.1175/JCLI-D-15-0826.1

Quantifying the contribution of glacier-melt water in the expansion of the largest lake in Tibet (Tong et al. 2016) http://onlinelibrary.wiley.com/doi/10.1002/2016JD025424/abstract

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New research – atmospheric composition (September 19, 2016)

Posted by Ari Jokimäki on September 19, 2016

Some of the latest papers on atmospheric composition (mainly on greenhouse gases and aerosols) are shown below. First a few highlighted papers with abstracts and then a list of some other papers. If this subject interests you, be sure to check also the other papers – they are by no means less interesting than the highlighted ones.

Highlights

A global catalogue of large SO2 sources and emissions derived from the Ozone Monitoring Instrument (Fioletov et al. 2016) http://www.atmos-chem-phys.net/16/11497/2016/

Abstract: Sulfur dioxide (SO2) measurements from the Ozone Monitoring Instrument (OMI) satellite sensor processed with the new principal component analysis (PCA) algorithm were used to detect large point emission sources or clusters of sources. The total of 491 continuously emitting point sources releasing from about 30 kt yr−1 to more than 4000 kt yr−1 of SO2 per year have been identified and grouped by country and by primary source origin: volcanoes (76 sources); power plants (297); smelters (53); and sources related to the oil and gas industry (65). The sources were identified using different methods, including through OMI measurements themselves applied to a new emission detection algorithm, and their evolution during the 2005–2014 period was traced by estimating annual emissions from each source. For volcanic sources, the study focused on continuous degassing, and emissions from explosive eruptions were excluded. Emissions from degassing volcanic sources were measured, many for the first time, and collectively they account for about 30 % of total SO2 emissions estimated from OMI measurements, but that fraction has increased in recent years given that cumulative global emissions from power plants and smelters are declining while emissions from oil and gas industry remained nearly constant. Anthropogenic emissions from the USA declined by 80 % over the 2005–2014 period as did emissions from western and central Europe, whereas emissions from India nearly doubled, and emissions from other large SO2-emitting regions (South Africa, Russia, Mexico, and the Middle East) remained fairly constant. In total, OMI-based estimates account for about a half of total reported anthropogenic SO2 emissions; the remaining half is likely related to sources emitting less than 30 kt yr−1 and not detected by OMI.

Re-evaluating the 1940s CO2 plateau (Bastos et al. 2016) http://www.biogeosciences.net/13/4877/2016/

Abstract: The high-resolution CO2 record from Law Dome ice core reveals that atmospheric CO2 concentration stalled during the 1940s (so-called CO2 plateau). Since the fossil-fuel emissions did not decrease during the period, this stalling implies the persistence of a strong sink, perhaps sustained for as long as a decade or more. Double-deconvolution analyses have attributed this sink to the ocean, conceivably as a response to the very strong El Niño event in 1940–1942. However, this explanation is questionable, as recent ocean CO2 data indicate that the range of variability in the ocean sink has been rather modest in recent decades, and El Niño events have generally led to higher growth rates of atmospheric CO2 due to the offsetting terrestrial response. Here, we use the most up-to-date information on the different terms of the carbon budget: fossil-fuel emissions, four estimates of land-use change (LUC) emissions, ocean uptake from two different reconstructions, and the terrestrial sink modelled by the TRENDY project to identify the most likely causes of the 1940s plateau. We find that they greatly overestimate atmospheric CO2 growth rate during the plateau period, as well as in the 1960s, in spite of giving a plausible explanation for most of the 20th century carbon budget, especially from 1970 onwards. The mismatch between reconstructions and observations during the CO2 plateau epoch of 1940–1950 ranges between 0.9 and 2.0 Pg C yr−1, depending on the LUC dataset considered. This mismatch may be explained by (i) decadal variability in the ocean carbon sink not accounted for in the reconstructions we used, (ii) a further terrestrial sink currently missing in the estimates by land-surface models, or (iii) LUC processes not included in the current datasets. Ocean carbon models from CMIP5 indicate that natural variability in the ocean carbon sink could explain an additional 0.5 Pg C yr−1 uptake, but it is unlikely to be higher. The impact of the 1940–1942 El Niño on the observed stabilization of atmospheric CO2 cannot be confirmed nor discarded, as TRENDY models do not reproduce the expected concurrent strong decrease in terrestrial uptake. Nevertheless, this would further increase the mismatch between observed and modelled CO2 growth rate during the CO2 plateau epoch. Tests performed using the OSCAR (v2.2) model indicate that changes in land use not correctly accounted for during the period (coinciding with drastic socioeconomic changes during the Second World War) could contribute to the additional sink required. Thus, the previously proposed ocean hypothesis for the 1940s plateau cannot be confirmed by independent data. Further efforts are required to reduce uncertainty in the different terms of the carbon budget during the first half of the 20th century and to better understand the long-term variability of the ocean and terrestrial CO2 sinks.

Trace gases in the atmosphere over Russian cities (Elansky et al. 2016) http://www.sciencedirect.com/science/article/pii/S1352231016306392

Abstract: Multiyear observational data (obtained at the mobile railroad laboratory in the course of the 1995–2010 TROICA experiments) on the composition and state of the atmosphere were used to study the features of both spatial and temporal variations in the contents of trace gases in the surface air layer over Russian cities. The obtained characteristics of urban air noticeably differ from those obtained at stationary stations. The emission fluxes of NOx, CO, and CH4 and their integral emissions from large cities have been estimated on the basis of observational data obtained at the mobile laboratory. The values of these emission fluxes reflect the state of urban infrastructure. The integral urban emissions of CO depend on the city size and vary from 50 Gg yr−1 for Yaroslavl to 130 Gg yr−1 for Yekaterinburg. For most cities, they agree with the EDGAR v4.2 data within the limits of experimental error. The agreement is worse for the emissions of NOx. The EDGAR v4.2 data on the emissions of CH4 seem to be overestimated..

Potential sea salt aerosol sources from frost flowers in the pan-Arctic region (Xu et al. 2016) http://onlinelibrary.wiley.com/doi/10.1002/2015JD024713/abstract

Abstract: In order to better represent observed wintertime aerosol mass and number concentrations in the pan-Arctic (60°N-90°N) region, we implemented an observationally-based parameterization for estimating sea salt production from frost flowers in the Community Earth System Model (CESM, version 1.2.1). In this work, we evaluate the potential influence of this sea salt source on the pan-Arctic climate. Results show that frost flower salt emissions increase the modeled surface sea salt aerosol mass concentration by roughly 200% at Barrow and 100% at Alert and accumulation-mode number concentration by about a factor of 2 at Barrow and more than a factor of 10 at Alert in the winter months when new sea ice and frost flowers are present. The magnitude of sea salt aerosol mass and number concentrations at the surface in Barrow during winter simulated by the model configuration that includes this parameterization agrees better with observations by 48% and 12%, respectively, than the standard CESM simulation without a frost-flower salt particle source. At Alert, the simulation with this parameterization overestimates observed sea salt aerosol mass concentration by 150% during winter in contrast to the underestimation of 63% in the simulation without this frost flower source, while it produces particle number concentration about 14% closer to observation than the standard CESM simulation. However, because the CESM version used here underestimates transported sulfate in winter, the reference accumulation-mode number concentrations at Alert are also underestimated. Adding these frost flower salt particle emissions increases sea salt aerosol optical depth by 10% in the pan-Arctic region and results in a small cooling at the surface. The increase in salt aerosol mass concentrations of a factor of 8 provides nearly two times the cloud condensation nuclei concentration at supersaturation of 0.1%, as well as 10% increases in cloud droplet number and 40% increases in liquid water content near coastal regions adjacent to continents. These cloud changes reduce longwave cloud forcing at the top of the atmosphere by 3% and cause a small surface warming, increasing the downward longwave flux at the surface by 1.8 W m−2 in the pan-Arctic under the present-day climate. This regional average longwave warming due to the presence of clouds attributed to frost flower sea salts is roughly half of previous observed surface longwave fluxes and cloud-forcing estimates reported in Alaska, implying that the longwave enhancement due to frost flower salts may be comparable to those estimated for anthropogenic aerosol emissions. Since the potential frost flower area is parameterized as the maximum possible region on which frost flowers grow for the modeled atmospheric temperature and sea ice conditions and the model underestimates the number of accumulation-mode particles from mid-latitude anthropogenic sources transported in winter, the calculated aerosol indirect effect of frost flower sea salts in this work can be regarded as an upper bound.

Early detection of volcanic hazard by lidar measurement of carbon dioxide (Fiorani et al. 2016) http://rd.springer.com/article/10.1007%2Fs11069-016-2209-0

Abstract: Volcanic gases give information on magmatic processes. In particular, anomalous releases of carbon dioxide precede volcanic eruptions. Up to now, this gas has been measured in volcanic plumes with conventional measurements that imply the severe risks of local sampling and can last many hours. For these reasons and for the great advantages of laser sensing, the thorough development of volcanic lidars has been undertaken at ENEA (Italian National Agency for New Technologies, Energy and Sustainable Economic Development). In fact, lidar profiling allows one to scan remotely volcanic plumes in a fast and continuous way, and with high spatial and temporal resolution. A differential absorption lidar instrument will be presented in this paper: BILLI (BrIdge voLcanic LIdar). It is based on injection-seeded Nd:YAG laser, double-grating dye laser, difference frequency mixing and optical parametric amplifier. BILLI is funded by the ERC (European Research Council) project BRIDGE (BRIDging the gap between Gas Emissions and geophysical observations at active volcanos). It scanned the gas emitted by Pozzuoli Solfatara (Naples, Italy) and Stromboli Volcano (Sicily, Italy) during field campaigns carried out from October 13 to 17, 2014, and from June 24 to 29, 2015, respectively. Carbon dioxide concentration maps were retrieved remotely in few minutes in the crater areas. To our knowledge, it is the first time that carbon dioxide in a volcanic plume is retrieved by lidar. This result represents the first direct measurement of this kind ever performed on active volcanos and shows the high potential of laser remote sensing in early detection of volcanic hazard.

Other papers

Validation and update of OMI Total Column Water Vapor product (Wang et al. 2016) http://www.atmos-chem-phys.net/16/11379/2016/

Long-term visibility variation in Athens (1931–2013): a proxy for local and regional atmospheric aerosol loads (Founda et al. 2016) http://www.atmos-chem-phys.net/16/11219/2016/

Particulate air pollution from wildfires in the Western US under climate change (Liu et al. 2016) http://rd.springer.com/article/10.1007%2Fs10584-016-1762-6

Climate-driven ground-level ozone extreme in the fall over the Southeast United States (Zhang et al. 2016) http://www.pnas.org/content/113/36/10025.short

Radon as a tracer of atmospheric influences on traffic-related air pollution in a small inland city (Williams et al. 2016) http://www.tellusb.net/index.php/tellusb/article/view/30967

Bioaerosols in the Earth system: Climate, health, and ecosystem interactions (Fröhlich-Nowoisky et al. 2016) http://www.sciencedirect.com/science/article/pii/S0169809516301995

The importance of non-fossil sources in carbonaceous aerosols in a megacity of central China during the 2013 winter haze episode: A source apportionment constrained by radiocarbon and organic tracers (Liu et al. 2016) http://www.sciencedirect.com/science/article/pii/S1352231016306677

Estimating Minimum Detection Times for Satellite Remote Sensing of Trends in Mean and Extreme Precipitable Water Vapor (Roman et al. 2016) http://journals.ametsoc.org/doi/abs/10.1175/JCLI-D-16-0303.1

A comprehensive estimate for loss of atmospheric carbon tetrachloride (CCl4) to the ocean (Butler et al. 2016) http://www.atmos-chem-phys.net/16/10899/2016/

Significant increase of summertime ozone at Mount Tai in Central Eastern China (Sun et al. 2016) http://www.atmos-chem-phys.net/16/10637/2016/

Snow Covered Soils Produce N2O that is Lost from Forested Catchments (Enanga et al. 2016) http://onlinelibrary.wiley.com/doi/10.1002/2016JG003411/abstract

Spatial and temporal variability of urban fluxes of methane, carbon monoxide and carbon dioxide above London, UK (Helfter et al. 2016) http://www.atmos-chem-phys.net/16/10543/2016/

Climatic variability of the column ozone over the Iranian plateau (Mousavi et al. 2016) http://rd.springer.com/article/10.1007%2Fs00703-016-0474-9

Long-term variation of stratospheric aerosols observed with lidars over Tsukuba, Japan from 1982 and Lauder, New Zealand from 1992 to 2015 (Sakai et al. 2016) http://onlinelibrary.wiley.com/doi/10.1002/2016JD025132/abstract

The natural oscillations in stratospheric ozone observed by the GROMOS microwave radiometer at the NDACC station Bern (Moreira et al. 2016) http://www.atmos-chem-phys.net/16/10455/2016/

A biogenic CO2 flux adjustment scheme for the mitigation of large-scale biases in global atmospheric CO2 analyses and forecasts (Agustí-Panareda et al. 2016) http://www.atmos-chem-phys.net/16/10399/2016/

Relationship of ground-level ozone with synoptic weather conditions in Chicago (Jing et al. 2016) http://www.sciencedirect.com/science/article/pii/S2212095516300335

Global detection of absorbing aerosols over the ocean in the red and near infrared spectral region (Waquet et al. 2016) http://onlinelibrary.wiley.com/doi/10.1002/2016JD025163/abstract

Atmospheric benzene observations from oil and gas production in the Denver Julesburg basin in July and August 2014 (Halliday et al. 2016) http://onlinelibrary.wiley.com/doi/10.1002/2016JD025327/abstract

Carbon monoxide climatology derived from the trajectory mapping of global MOZAIC-IAGOS data (Osman et al. 2016) http://www.atmos-chem-phys.net/16/10263/2016/

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New research – climate change impacts on biosphere (September 14, 2016)

Posted by Ari Jokimäki on September 14, 2016

Some of the latest papers on climate change impacts on biosphere are shown below. First a few highlighted papers with abstracts and then a list of some other papers. If this subject interests you, be sure to check also the other papers – they are by no means less interesting than the highlighted ones.

Highlights

Increasing nest predation will be insufficient to maintain polar bear body condition inthe face of sea-ice loss (Dey et al. 2016) http://onlinelibrary.wiley.com/doi/10.1111/gcb.13499/abstract

Abstract: Climate change can influence interspecific interactions by differentially affecting species-specific phenology. In seasonal ice environments, there is evidence that polar bear predation of Arctic bird eggs is increasing because of earlier sea ice break-up, which forces polar bears into near-shore terrestrial environments where Arctic birds are nesting. Because polar bears can consume a large number of nests before becoming satiated, and because they can swim between island colonies, they could have dramatic influences on seabird and seaduck reproductive success. However, it is unclear whether nest foraging can provide an energetic benefit to polar bear populations, especially given the capacity of bird populations to redistribute in response to increasing predation pressure. In this study, we develop a spatially explicit agent-based model of the predator-prey relationship between polar bears and common eiders, a common and culturally important bird species for northern peoples. Our model is composed of two types of agents (polar bear agents, and common eider hen agents) whose movements and decision heuristics are based on species-specific bioenergetic and behavioral ecological principles, and are influenced by historical and extrapolated sea ice conditions. Our model reproduces empirical findings that polar bear predation of bird nests is increasing, and predicts an accelerating relationship between advancing ice break-up dates and the number of nests depredated. Despite increases in nest predation, our model predicts that polar bear body condition during the ice-free period will continue to decline. Finally, our model predicts that common eider nests will become more dispersed and will move closer to the mainland in response to increasing predation, possibly increasing their exposure to land-based predators, and influencing the livelihood of local people that collect eider eggs and down. These results show that predator-prey interactions can have non-linear responses to changes in climate, and provides important predictions of ecology change in Arctic ecosystems.

Lizards fail to plastically adjust nesting behavior or thermal tolerance as needed to buffer populations from climate warming (Telemaco et al. 2016) http://onlinelibrary.wiley.com/doi/10.1111/gcb.13476/abstract

Abstract: Although observations suggest the potential for phenotypic plasticity to allow adaptive responses to climate change, few experiments have assessed that potential. Modeling suggests that Sceloporus tristichus lizards will need increased nest depth, shade cover, or embryonic thermal tolerance to avoid reproductive failure resulting from climate change. To test for such plasticity, we experimentally examined how maternal temperatures affect nesting behavior and embryonic thermal sensitivity. The temperature regime that females experienced while gravid did not affect nesting behavior, but warmer temperatures at the time of nesting reduced nest depth. Additionally, embryos from heat-stressed mothers displayed increased sensitivity to high-temperature exposure. Simulations suggest that critically low temperatures, rather than high temperatures, historically limit development of our study population. Thus, the plasticity needed to buffer this population has not been under selection. Plasticity will likely fail to compensate for ongoing climate change when such change results in novel stressors.

Adapt, move, or die – how will tropical coral reef fishes cope with ocean warming? (Habary et al. 2016) http://onlinelibrary.wiley.com/doi/10.1111/gcb.13488/abstract

Abstract: Previous studies hailed thermal tolerance and the capacity for organisms to acclimate and adapt as the primary pathways for species survival under climate change. Here we challenge this theory. Over the past decade more than 365 tropical stenothermal fish species have been documented moving pole-ward, away from ocean warming hotspots where temperatures 2-3 °C above long-term annual means can compromise critical physiological processes. We examined the capacity of a model species – a thermally-sensitive coral reef fish, Chromis viridis (Pomacentridae) – to use preference behaviour to regulate its body temperature. Movement could potentially circumvent the physiological stress response associated with elevated temperatures and may be a strategy relied upon before genetic adaptation can be effectuated. Individuals were maintained at one of six temperatures (23, 25, 27, 29, 31 and 33 °C) for at least six weeks. We compared the relative importance of acclimation temperature to changes in upper critical thermal limits, aerobic metabolic scope, and thermal preference. While acclimation temperature positively affected the upper critical thermal limit, neither aerobic metabolic scope nor thermal preference exhibited such plasticity. Importantly, when given the choice to stay in a habitat reflecting their acclimation temperatures or relocate, fish acclimated to end-of-century predicted temperatures (i.e., 31 or 33 °C) preferentially sought out cooler temperatures, those equivalent to long-term summer averages in their natural habitats (~29 °C). This was also the temperature providing the greatest aerobic metabolic scope and body condition across all treatments. Consequently, acclimation can confer plasticity in some performance traits, but may be an unreliable indicator of the ultimate survival and distribution of mobile stenothermal species under global warming. Conversely, thermal preference can arise long before, and remain long after, the harmful effects of elevated ocean temperatures take hold and may be the primary driver of the escalating pole-ward migration of species.

Projections of climate change impacts on central America tropical rainforest (Lyra et al. 2016) http://rd.springer.com/article/10.1007%2Fs10584-016-1790-2

Abstract: Tropical rainforest plays an important role in the global carbon cycle, accounting for a large part of global net primary productivity and contributing to CO2 sequestration. The objective of this work is to simulate potential changes in the rainforest biome in Central America subject to anthropogenic climate change under two emissions scenarios, RCP4.5 and RCP8.5. The use of a dynamic vegetation model and climate change scenarios is an approach to investigate, assess or anticipate how biomes respond to climate change. In this work, the Inland dynamic vegetation model was driven by the Eta regional climate model simulations. These simulations accept boundary conditions from HadGEM2-ES runs in the two emissions scenarios. The possible consequences of regional climate change on vegetation properties, such as biomass, net primary production and changes in forest extent and distribution, were investigated. The Inland model projections show reductions in tropical forest cover in both scenarios. The reduction of tropical forest cover is greater in RCP8.5. The Inland model projects biomass increases where tropical forest remains due to the CO2 fertilization effect. The future distribution of predominant vegetation shows that some areas of tropical rainforest in Central America are replaced by savannah and grassland in RCP4.5. Inland projections under both RCP4.5 and RCP8.5 show a net primary productivity reduction trend due to significant tropical forest reduction, temperature increase, precipitation reduction and dry spell increments, despite the biomass increases in some areas of Costa Rica and Panama. This study may provide guidance to adaptation studies of climate change impacts on the tropical rainforests in Central America.

Interactive effects of temperature and pCO2 on sponges: from the cradle to the grave (Bennett et al. 2016) http://onlinelibrary.wiley.com/doi/10.1111/gcb.13474/abstract

Abstract: As atmospheric CO2 concentrations rise, associated ocean warming (OW) and ocean acidification (OA) are predicted to cause declines in reef-building corals globally, shifting reefs from coral-dominated systems to those dominated by less sensitive species. Sponges are important structural and functional components of coral reef ecosystems, but despite increasing field based evidence that sponges may be ‘winners’ in response to environmental degradation, our understanding of how they respond to the combined effects of OW and OA is limited. To determine the tolerance of adult sponges to climate change, four abundant Great Barrier Reef species were experimentally exposed to OW and OA levels predicted for 2100, under two CO2 Representative Concentration Pathways (RCPs). The impact of OW and OA on early life history stages was also assessed for one of these species to provide a more holistic view of species impacts. All species were generally unaffected by conditions predicted under RCP6.0, although environmental conditions projected under RCP8.5 caused significant adverse effects; with elevated temperature decreasing the survival of all species, increasing levels of tissue necrosis and bleaching, elevating respiration rates and decreasing photosynthetic rates. OA alone had little adverse effect, even under RCP8.5 concentrations. Importantly, the interactive effect of OW and OA varied between species with different nutritional modes, with elevated pCO2 exacerbating temperature stress in heterotrophic species but mitigating temperature stress in phototrophic species. This antagonistic interaction was reflected by reduced mortality, necrosis and bleaching of phototrophic species in the highest OW/OA treatment. Survival and settlement success of C. foliascens larvae were unaffected by experimental treatments, and juvenile sponges exhibited greater tolerance to OW than their adult counterparts. With elevated pCO2 providing phototrophic species with protection from elevated temperature, across different life-stages, climate change may ultimately drive a shift in the composition of sponge assemblages towards a dominance of phototrophic species.

Other papers

Stability in a changing world – palm community dynamics in the hyperdiverse western Amazon over 17 years (Olivares et al. 2016) http://onlinelibrary.wiley.com/doi/10.1111/gcb.13494/abstract

Recent climate hiatus revealed dual control by temperature and drought on the stem growth of Mediterranean Quercus ilex (Lempereur et al. 2016) http://onlinelibrary.wiley.com/doi/10.1111/gcb.13495/abstract

Environmental constraints on Holocene cold-water coral reef growth off Norway: Insights from a multi-proxy approach (Raddatz et al. 2016) http://onlinelibrary.wiley.com/doi/10.1002/2016PA002974/abstract

Projected shifts in fish species dominance in Wisconsin lakes under climate change (Hansen et al. 2016) http://onlinelibrary.wiley.com/doi/10.1111/gcb.13462/abstract

Phenological research of climate changes in the north part of Lithuania by the phenological garden of Šiauliai University (Klimienė et al. 2016) http://rd.springer.com/article/10.1007%2Fs00484-016-1211-2

Stream network geomorphology mediates predicted vulnerability of anadromous fish habitat to hydrologic change in southeast Alaska (Sloat et al. 2016) http://onlinelibrary.wiley.com/doi/10.1111/gcb.13466/abstract

Diatom assemblages reveal regional-scale differences in lake responses to recent climate change at the boreal-tundra ecotone, Manitoba, Canada (Shinneman et al. 2016) http://rd.springer.com/article/10.1007%2Fs10933-016-9911-5

Temperature sensitivity thresholds to warming and cooling in phenophases of alpine plants (Meng et al. 2016) http://rd.springer.com/article/10.1007%2Fs10584-016-1802-2

Relationships between climate, topography, water use and productivity in two key Mediterranean forest types with different water-use strategies (Helman et al. 2016) http://www.sciencedirect.com/science/article/pii/S0168192316303732

Ant assemblages have darker and larger members in cold environments (Bishop et al. 2016) http://onlinelibrary.wiley.com/doi/10.1111/geb.12516/abstract

Spring blooms in the Baltic Sea have weakened but lengthened from 2000 to 2014 (Groetsch et al. 2016) http://www.biogeosciences.net/13/4959/2016/

Current and projected global distribution of Phytophthora cinnamomi, one of the world’s worst plant pathogens (Burgess et al. 2016) http://onlinelibrary.wiley.com/doi/10.1111/gcb.13492/abstract

Assessing drought-driven mortality trees with physiological process-based models (Hendrik & Maxime, 2016) http://www.sciencedirect.com/science/article/pii/S0168192316303744

Global patterns in lake ecosystem responses to warming based on the temperature dependence of metabolism (Kraemer et al. 2016) http://onlinelibrary.wiley.com/doi/10.1111/gcb.13459/abstract

Additive effects of temperature and infection with an acanthocephalan parasite on the shredding activity of Gammarus fossarum (Crustacea: Amphipoda): the importance of aggregative behavior (Labaude et al. 2016) http://onlinelibrary.wiley.com/doi/10.1111/gcb.13490/abstract

Growth of northern deciduous trees under increasing atmospheric humidity: possible mechanisms behind the growth retardation (Sellin et al. 2016) http://rd.springer.com/article/10.1007%2Fs10113-016-1042-z

Responses of net primary productivity to phenological dynamics in the Tibetan Plateau, China (Wang et al. 2016) http://www.sciencedirect.com/science/article/pii/S0168192316303756

Variation in White Stork (Ciconia ciconia) diet along a climatic gradient and across rural-to-urban landscapes in North Africa (Chenchouni, 2016) http://rd.springer.com/article/10.1007%2Fs00484-016-1232-x

Species-specific responses to climate change and community composition determine future calcification rates of Florida Keys reefs (Okazaki et al. 2016) http://onlinelibrary.wiley.com/doi/10.1111/gcb.13481/abstract

Aleppo pine forests from across Spain show drought-induced growth decline and partial recovery (Gazol et al. 2016) http://www.sciencedirect.com/science/article/pii/S0168192316303690

Climate change will increase the naturalization risk from garden plants in Europe (Dullinger et al. 2016) http://onlinelibrary.wiley.com/doi/10.1111/geb.12512/abstract

Coarse climate change projections for species living in a fine-scaled world (Nadeau et al. 2016) http://onlinelibrary.wiley.com/doi/10.1111/gcb.13475/abstract

Confounding effects of spatial variation on shifts in phenology (de Keyzer et al. 2016) http://onlinelibrary.wiley.com/doi/10.1111/gcb.13472/abstract

Climate warming reduces fish production and benthic habitat in Lake Tanganyika, one of the most biodiverse freshwater ecosystems (Cohen et al. 2016) http://www.pnas.org/content/113/34/9563.short

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Papers on micro-organisms in permafrost

Posted by Ari Jokimäki on September 13, 2016

This is a list of papers on micro-organisms in permafrost. The list is not complete, and will most likely be updated in future in order to make it more thorough and more representative.

Functional Characterization of Bacteria Isolated from Ancient Arctic Soil Exposes Diverse Resistance Mechanisms to Modern Antibiotics (Perron et al. 2015) [FULL TEXT]
Abstract: “Using functional metagenomics to study the resistomes of bacterial communities isolated from different layers of the Canadian high Arctic permafrost, we show that microbial communities harbored diverse resistance mechanisms at least 5,000 years ago. Among bacteria sampled from the ancient layers of a permafrost core, we isolated eight genes conferring clinical levels of resistance against aminoglycoside, β-lactam and tetracycline antibiotics that are naturally produced by microorganisms. Among these resistance genes, four also conferred resistance against amikacin, a modern semi-synthetic antibiotic that does not naturally occur in microorganisms. In bacteria sampled from the overlaying active layer, we isolated ten different genes conferring resistance to all six antibiotics tested in this study, including aminoglycoside, β-lactam and tetracycline variants that are naturally produced by microorganisms as well as semi-synthetic variants produced in the laboratory. On average, we found that resistance genes found in permafrost bacteria conferred lower levels of resistance against clinically relevant antibiotics than resistance genes sampled from the active layer. Our results demonstrate that antibiotic resistance genes were functionally diverse prior to the anthropogenic use of antibiotics, contributing to the evolution of natural reservoirs of resistance genes.”
Citation: Perron GG, Whyte L, Turnbaugh PJ, Goordial J, Hanage WP, Dantas G, et al. (2015) Functional Characterization of Bacteria Isolated from Ancient Arctic Soil Exposes Diverse Resistance Mechanisms to Modern Antibiotics. PLoS ONE 10(3): e0069533. doi:10.1371/journal.pone.0069533.

Molecular characterization of bacteria from permafrost of the Taylor Valley, Antarctica (Bakermans et al. 2014) [FULL TEXT]
Abstract: “While bacterial communities from McMurdo Dry Valley soils have been studied using molecular techniques, data from permafrost are particularly scarce given the logistical difficulties of sampling. This study examined the molecular diversity and culturability of bacteria in permafrost from the Taylor Valley (TV), Antarctica. A 16S rRNA gene clone library was constructed to assess bacterial diversity, while a clone library of the RNA polymerase beta subunit (rpoB) gene was constructed to examine amino acid composition of an essential protein-coding gene. The 16S rRNA gene clone library was dominated by Acidobacteria from Gp6 and Gemmatimonadetes. The rpoB gene clone library (created with primers designed in this study) was also dominated by Acidobacteria. The ability of sequence analyses to garner additional information about organisms represented by TV sequences was explored. Specifically, optimum growth temperature was estimated from the stem GC content of the 16S rRNA gene, while potential cold adaptations within translated rpoB sequences were assessed. These analyses were benchmarked using known psychrophiles and mesophiles. Bioinformatic analyses suggested that many TV sequences could represent organisms capable of activity at low temperatures. Plate counts confirmed that c. 103 cells per gram permafrost remained viable and were culturable, while laboratory respiration assays demonstrated that microbial activity occurred at −5 °C and peaked at 15 °C.”
Citation: Bakermans, C., Skidmore, M. L., Douglas, S. and McKay, C. P. (2014), Molecular characterization of bacteria from permafrost of the Taylor Valley, Antarctica. FEMS Microbiol Ecol, 89: 331–346. doi:10.1111/1574-6941.12310.

Bacterial growth at −15 °C; molecular insights from the permafrost bacterium Planococcus halocryophilus Or1 (Mykytczuk et al. 2013) [FULL TEXT]
Abstract: “Planococcus halocryophilus strain Or1, isolated from high Arctic permafrost, grows and divides at −15 °C, the lowest temperature demonstrated to date, and is metabolically active at −25 °C in frozen permafrost microcosms. To understand how P. halocryophilus Or1 remains active under the subzero and osmotically dynamic conditions that characterize its native permafrost habitat, we investigated the genome, cell physiology and transcriptomes of growth at −15 °C and 18% NaCl compared with optimal (25 °C) temperatures. Subzero growth coincides with unusual cell envelope features of encrustations surrounding cells, while the cytoplasmic membrane is significantly remodeled favouring a higher ratio of saturated to branched fatty acids. Analyses of the 3.4 Mbp genome revealed that a suite of cold and osmotic-specific adaptive mechanisms are present as well as an amino acid distribution favouring increased flexibility of proteins. Genomic redundancy within 17% of the genome could enable P. halocryophilus Or1 to exploit isozyme exchange to maintain growth under stress, including multiple copies of osmolyte uptake genes (Opu and Pro genes). Isozyme exchange was observed between the transcriptome data sets, with selective upregulation of multi-copy genes involved in cell division, fatty acid synthesis, solute binding, oxidative stress response and transcriptional regulation. The combination of protein flexibility, resource efficiency, genomic plasticity and synergistic adaptation likely compensate against osmotic and cold stresses. These results suggest that non-spore forming P. halocryophilus Or1 is specifically suited for active growth in its Arctic permafrost habitat (ambient temp. ~−16 °C), indicating that such cryoenvironments harbor a more active microbial ecosystem than previously thought.”
Citation: Nadia C S Mykytczuk, Simon J Foote, Chris R Omelon, Gordon Southam, Charles W Greer, Lyle G Whyte, The ISME Journal (2013) 7, 1211–1226; doi:10.1038/ismej.2013.8.

Climate change and zoonotic infections in the Russian Arctic (Revich et al. 2012) [FULL TEXT]
Abstract: “Climate change in the Russian Arctic is more pronounced than in any other part of the country. Between 1955 and 2000, the annual average air temperature in the Russian North increased by 1.2°C. During the same period, the mean temperature of upper layer of permafrost increased by 3°C. Climate change in Russian Arctic increases the risks of the emergence of zoonotic infectious diseases. This review presents data on morbidity rates among people, domestic animals and wildlife in the Russian Arctic, focusing on the potential climate related emergence of such diseases as tick-borne encephalitis, tularemia, brucellosis, leptospirosis, rabies, and anthrax.”
Citation: Boris Revich, Nikolai Tokarevich, Alan J. Parkinson, Int J Circumpolar Health 2012, 71: 18792 – http://dx.doi.org/10.3402/ijch.v71i0.18792.

On the prospects of microbiological research on mammoth fauna in permafrost (Neustroev, 2012)
Abstract: “Research of mammoth microflora is of current interest in terms of psychrophiles, cryoanabiosis, and the peculiar properties of ecology and evolution of microorganisms. Recovered Bacillus bacteria strains of the mammoths express antagonistic activity against pathogenic and opportunistic microorganisms. Moreover, the strains are antibiotic resistant and salt tolerant. The obtained data is consistent with research on biocoenosis of domestic and wild animals, cryogenic soil, air, atmosphere precipitation, and plants. Having high biological activity, Bacillus bacteria are the dominant group in the microbiocenosis environment in permafrost.”
Citation: M.P. Neustroev, Quaternary International, Volume 255, 26 March 2012, Pages 139–140, http://dx.doi.org/10.1016/j.quaint.2011.06.003.

43. Global warming and expanding the range of feral conditions in Yakutia – The coldest region of the North-East Asia (Solomonov et al. 2012)
Abstract: “In Yakutia, there has long been a number of natural foci of infectious human and animal diseases such as tularemia, anthrax, rabies, brucellosis, leptospirosis and others. The circulation of pathogens in nature is closely connected with the peculiarities of natural ecosystems and their animal populations, especially the mass species of birds and mammals and their ecto-and endoparasites. Global warming has caused the expansion to the north of the range of many species of birds and their ectoparasites from the southern parts of the Asia–Pacific region. There was the possibility of the spread causative agent of avian influenza H5N1 dangerous to humans, in-line with those observed in recent decades, global warming and the expansion of the range of animal-carriers and custodians of infectious agents are expanding the range of feral diseases such as rabies, brucellosis,and encephalitis, stable foci of new diseases, including pseudotuberculosis, have appeared in our region. With further advancement of the classical forms of rabies in South Yakutia in the central and northern areas of the Arctic, the counter-propagation form of rabies may occur to the south, with the genetic restructuring of their agents as a result of recombination of genes and new mutations. Melting of permafrost soils and an irrigation of territories can promote “awakening” of the centres, previously widespread in the region, of a malignant anthrax and natural smallpox. There is concern has about the recently established detection of viable, including spore-forming, micro-organisms in the remains of the mammoth fauna of the natural burial sites in the Late Pleistocene permafrost sediments over time. The latter indicates that there is potential for the release of pathogens from the surface of especially dangerous infections from that era (epidemiological echo). Previously, Somov (1974), who worked many years in Chukotka and other regions of the Russian Far East, put forward a hypothesis on the preservation of psychrophilic pathogens infections at low temperatures of the environment in saprophytic state that only if it enters the human body become virulent. In this regard, we suggested in 1980 that “the further development of the northern territories may appear natural foci of new, perhaps previously unknown infectious diseases”. Thus, global warming contributes to increased incidence of especially dangerous infections by expanding the range of animal carriers and disseminators of infection due to possible preservation at low temperatures in the state of saprophytic pathogens in the active state.”
Citation: N.G. Solomonov, V.F. Chernyavskyy, B.M. Kerschengoltz, O.I. Nikiphorov, E.S. Khlebnyy, Cryobiology, Volume 65, Issue 3, December 2012, Pages 353, http://dx.doi.org/10.1016/j.cryobiol.2012.07.044.

Thawing of permafrost may disturb historic cattle burial grounds in East Siberia (Revich & Podolnaya, 2011) [FULL TEXT]
Abstract: “Climate warming in the Arctic may increase the risk of zoonoses due to expansion of vector habitats, improved chances of vector survival during winter, and permafrost degradation. Monitoring of soil temperatures at Siberian cryology control stations since 1970 showed correlations between air temperatures and the depth of permafrost layer that thawed during summer season. Between 1900s and 1980s, the temperature of surface layer of permafrost increased by 2–4°C; and a further increase of 3°C is expected. Frequent outbreaks of anthrax caused death of 1.5 million deer in Russian North between 1897 and 1925. Anthrax among people or cattle has been reported in 29,000 settlements of the Russian North, including more than 200 Yakutia settlements, which are located near the burial grounds of cattle that died from anthrax. Statistically significant positive trends in annual average temperatures were established in 8 out of 17 administrative districts of Yakutia for which sufficient meteorological data were available. At present, it is not known whether further warming of the permafrost will lead to the release of viable anthrax organisms. Nevertheless, we suggest that it would be prudent to undertake careful monitoring of permafrost conditions in all areas where an anthrax outbreak had occurred in the past.”
Citation: Boris A. Revich, Marina A. Podolnaya, Global Health Action 2011, 4: 8482 – DOI: 10.3402/gha.v4i0.8482.

Biogeochemistry of permafrost in Central Yakutia (Brouchkov et al. 2011) [FULL TEXT]
Abstract: “Permafrost is widespread in the Northern Hemisphere and is as old as hundreds of thousands to millions of years. Frozen ground stores living microorganisms which remain unfrozen in the relatively warm environment (–2…–8 °C) but are immobilized and may be about the age of the host permafrost. A strain of Bacillus sp. was isolated from ~3 Ma permafrost and its 16S rDNA sequence was identified. A large group of microorganisms including fungi was isolated from the wedge ice. Permafrost deposits contain invertase, urease, katalase and dehydrogenase.”
Citation: A.V. Brouchkov, V.P. Melnikov, M.V. Schelchkova, G.I. Griva, V.E. Repin, E.V. Brenner, M. Tanaka, EARTH CRYOSPHERE, 2011, Vol. XV, № 4, p. 79-87.

Multi-locus real-time PCR for quantitation of bacteria in the environment reveals Exiguobacterium to be prevalent in permafrost (Rodrigues & Tiedje, 2007) [FULL TEXT]
Abstract: “We developed a multi-locus quantitative PCR approach to minimize problems of precision, sensitivity and primer specificity for quantifying a targeted microbial group in nature. This approach also avoids a systematic error in population quantitation when 16S rRNA genes are used because of copy number heterogeneity. Specific primers were designed to assess the abundance of psychrotrophic and mesophilic Exiguobacterium spp. that excluded the thermophilic members of the genus. The chosen primers targeted genes for DNA gyrase B (gyrB), the beta subunit of the RNA polymerase gene (rpoB) and a hypothetical gene so far found only in this group. The results demonstrate that the multiple primer approach provides a more reliable estimate of population density; that the targeted Exiguobacterium group is found at a median density of 50 000 gene copies per μg of total community DNA in 27 of 29 permafrost soils but was found in only one of the four temperate and tropical soils tested.”
Citation: Rodrigues, D. F. and Tiedje, J. M. (2007), Multi-locus real-time PCR for quantitation of bacteria in the environment reveals Exiguobacterium to be prevalent in permafrost. FEMS Microbiology Ecology, 59: 489–499. doi:10.1111/j.1574-6941.2006.00233.x.

Diversity and distribution of alkaliphilic psychrotolerant bacteria in the Qinghai–Tibet Plateau permafrost region (Zhang et al. 2007)
Abstract: “The Qinghai–Tibet Plateau represents a unique permafrost environment, being a result of high elevation caused by land uplift. And the urgency was that plateau permafrost was degrading rapidly under the current predicted climatic warming scenarios. Hence, the permafrost there was sampled to recover alkaliphilic bacteria populations. The viable bacteria on modified PYGV agar were varied between 102 and 105 CFU/g of dry soil. Forty-eight strains were gained from 18 samples. Through amplified ribosomal DNA restriction analysis (ARDRA) and phylogenetic analyses, these isolates fell into three categories: high G + C gram positive bacteria (82.3%), low G + C gram positive bacteria (7.2%), and gram negative α-proteobacteria (10.5%). The strains could grow at pH values ranging from 6.5 to 10.5 with optimum pH in the range of 9–9.5. Their growth temperatures were below 37°C and the optima ranging from 10 to 15°C. All strains grew well when NaCl concentration was below 15%. These results indicate that there are populations of nonhalophilic alkaliphilic psychrotolerant bacteria within the permafrost of the Qinhai-Tibet plateau. The abilities of many of the strains to produce extracellular protease, amylase and cellulase suggest that they might be of potential value for biotechnological exploitation.”
Citation: Zhang, G., Ma, X., Niu, F. et al. Extremophiles (2007) 11: 415. doi:10.1007/s00792-006-0055-9.

Characterization of the microbial diversity in a permafrost sample from the Canadian high Arctic using culture-dependent and culture-independent methods (Steven et al. 2007) [FULL TEXT]
Abstract: “A combination of culture-dependent and culture-independent methodologies (Bacteria and Archaea 16S rRNA gene clone library analyses) was used to determine the microbial diversity present within a geographically distinct high Arctic permafrost sample. Culturable Bacteria isolates, identified by 16S rRNA gene sequencing, belonged to the phyla Firmicutes, Actinobacteria and Proteobacteria with spore-forming Firmicutes being the most abundant; the majority of the isolates (19/23) were psychrotolerant, some (11/23) were halotolerant, and three isolates grew at −5°C. A Bacteria 16S rRNA gene library containing 101 clones was composed of 42 phylotypes related to diverse phylogenetic groups including the Actinobacteria, Proteobacteria, Firmicutes, Cytophaga – Flavobacteria – Bacteroides, Planctomyces and Gemmatimonadetes; the bacterial 16S rRNA gene phylotypes were dominated by Actinobacteria- and Proteobacteria-related sequences. An Archaea 16S rRNA gene clone library containing 56 clones was made up of 11 phylotypes and contained sequences related to both of the major Archaea domains (Euryarchaeota and Crenarchaeota); the majority of sequences in the Archaea library were related to halophilic Archaea. Characterization of the microbial diversity existing within permafrost environments is important as it will lead to a better understanding of how microorganisms function and survive in such extreme cryoenvironments.”
Citation: Steven, B., Briggs, G., McKay, C. P., Pollard, W. H., Greer, C. W. and Whyte, L. G. (2007), Characterization of the microbial diversity in a permafrost sample from the Canadian high Arctic using culture-dependent and culture-independent methods. FEMS Microbiology Ecology, 59: 513–523. doi:10.1111/j.1574-6941.2006.00247.x.

Microbial ecology and biodiversity in permafrost (Steven et al. 2006) [FULL TEXT]
Abstract: “Permafrost represents 26% of terrestrial soil ecosystems; yet its biology, essentially microbiology, remains relatively unexplored. The permafrost environment is considered extreme because indigenous microorganisms must survive prolonged exposure to subzero temperatures and background radiation for geological time scales in a habitat with low water activity and extremely low rates of nutrient and metabolite transfer. Yet considerable numbers and biodiversity of bacteria exist in permafrost, some of which may be among the most ancient viable life on Earth. This review describes the permafrost environment as a microbial habitat and reviews recent studies examining microbial biodiversity found in permafrost as well as microbial growth and activity at ambient in situ subzero temperatures. These investigations suggest that functional microbial ecosystems exist within the permafrost environment and may have important implications on global biogeochemical processes as well as the search for past or extant life in permafrost presumably present on Mars and other bodies in our solar system.”
Citation: Steven, B., Léveillé, R., Pollard, W.H. et al. Extremophiles (2006) 10: 259. doi:10.1007/s00792-006-0506-3.

Characterization of potential stress responses in ancient Siberian permafrost psychroactive bacteria (Ponder et al. 2005) [FULL TEXT]
Abstract: “Past studies of cold-acclimated bacteria have focused primarily on organisms not capable of sub-zero growth. Siberian permafrost isolates Exiguobacterium sp. 255-15 and Psychrobacter sp. 273-4, which grow at subzero temperatures, were used to study cold-acclimated physiology. Changes in membrane composition and exopolysaccharides were defined as a function of growth at 24, 4 and −2.5 °C in the presence and absence of 5% NaCl. As expected, there was a decrease in fatty acid saturation and chain length at the colder temperatures and a further decrease in the degree of saturation at higher osmolarity. A shift in carbon source utilization and antibiotic resistance occurred at 4 versus 24 °C growth, perhaps due to changes in the membrane transport. Some carbon substrates were used uniquely at 4 °C and, in general, increased antibiotic sensitivity was observed at 4 °C. All the permafrost strains tested were resistant to long-term freezing (1 year) and were not particularly unique in their UVC tolerance. Most of the tested isolates had moderate ice nucleation activity, and particularly interesting was the fact that the Gram-positive Exiguobacterium showed some soluble ice nucleation activity. In general the features measured suggest that the Siberian organisms have adapted to the conditions of long-term freezing at least for the temperatures of the Kolyma region which are −10 to −12 °C where intracellular water is likely not frozen.”
Citation: Monica A. Ponder, Sarah J. Gilmour, Peter W. Bergholz, Carol A. Mindock, Rawle Hollingsworth, Michael F. Thomashow, James M. Tiedje, FEMS Microbiology Ecology, Volume 53, Issue 1, Pp. 103 – 115, DOI: http://dx.doi.org/10.1016/j.femsec.2004.12.003.

Long-term persistence of bacterial DNA (Willerslev et al. 2004) [FULL TEXT]
Abstract: “The persistence of bacterial DNA over geological timespans remains a contentious issue. In direct contrast to in vitro based predictions, bacterial DNA and even culturable cells have been reported from various ancient specimens many million years (Ma) old. As both ancient DNA studies and the revival of microorganisms are known to be susceptible to contamination, it is concerning that these results have not been independently replicated to confirm their authenticity. Furthermore, they show no obvious relationship between sample age, and either bacterial composition or DNA persistence, although bacteria are known to differ markedly in hardiness and resistance to DNA degradation. We present the first study of DNA durability and degradation of a broad variety of bacteria preserved under optimal frozen conditions, using rigorous ancient DNA methods. The results demonstrate that non-spore-forming gram-positive (GP) Actinobacteria are by far the most durable, out-surviving endospore-formers such as Bacillaceae and Clostridiaceae. The observed DNA degradation rates are close to theoretical calculations, indicating a limit of ca. 400 thousand years (kyr) beyond which PCR amplifications are prevented by the formation of DNA interstrand crosslinks (ICLs).”
Citation: Eske Willerslev, Anders J. Hansen, Regin Rønn, Tina B. Brand, Ian Barnes, Carsten Wiuf, David Gilichinsky, David Mitchell, Alan Cooper, Current Biology, Volume 14, Issue 1, 6 January 2004, Pages R9–R10, http://dx.doi.org/10.1016/j.cub.2003.12.012.

Reproduction and metabolism at − 10°C of bacteria isolated from Siberian permafrost (Bakermans et al. 2003) [FULL TEXT]
Abstract: “We report the isolation and properties of several species of bacteria from Siberian permafrost. Half of the isolates were spore-forming bacteria unable to grow or metabolize at subzero temperatures. Other Gram-positive isolates metabolized, but never exhibited any growth at − 10°C. One Gram-negative isolate metabolized and grew at − 10°C, with a measured doubling time of 39 days. Metabolic studies of several isolates suggested that as temperature decreased below + 4°C, the partitioning of energy changes with much more energy being used for cell maintenance as the temperature decreases. In addition, cells grown at − 10°C exhibited major morphological changes at the ultrastructural level.”
Citation: Bakermans, C., Tsapin, A. I., Souza-Egipsy, V., Gilichinsky, D. A. and Nealson, K. H. (2003), Reproduction and metabolism at − 10°C of bacteria isolated from Siberian permafrost. Environmental Microbiology, 5: 321–326. doi:10.1046/j.1462-2920.2003.00419.x.

Low-temperature recovery strategies for the isolation of bacteria from ancient permafrost sediments (Vishnivetskaya et al. 2000) [FULL TEXT]
Abstract: “Permafrost represents a unique ecosystem that has allowed the prolonged survival of certain bacterial lineages at subzero temperatures. To better understand the permafrost microbial community, it is important to identify isolation protocols that optimize the recovery of genetically diverse bacterial lineages. We have investigated the impact of different low-temperature isolation protocols on recovery of aerobic bacteria from northeast Siberian permafrost of variable geologic origin and frozen for 5000 to 3 million years. Low-nutrient media enhanced the quantitative recovery of bacteria, whereas the isolation of diverse morphotypes was maximized on rich media. Cold enrichments done directly in natural, undisturbed permafrost led not only to recovery of increased numbers of bacteria but also to isolation of genotypes not recovered by means of liquid low-temperature enrichments. On the other hand, direct plating and growth at 4°C also led to recovery of diverse genotypes, some of which were not recovered following enrichment. Strains recovered from different permafrost samples were predominantly oligotrophic and non-spore-forming but were otherwise variable from each other in terms of a number of bacteriological characteristics. Our data suggest that a combination of isolation protocols from different permafrost samples should be used to establish a culture-based survey of the different bacterial lineages in permafrost.”
Citation: Vishnivetskaya, T., Kathariou, S., McGrath, J. et al. Extremophiles (2000) 4: 165. doi:10.1007/s007920070031.

Metabolic Activity of Permafrost Bacteria below the Freezing Point (Rivkina et al. 2000) [FULL TEXT]
Abstract: “Metabolic activity was measured in the laboratory at temperatures between 5 and −20°C on the basis of incorporation of14C-labeled acetate into lipids by samples of a natural population of bacteria from Siberian permafrost (permanently frozen soil). Incorporation followed a sigmoidal pattern similar to growth curves. At all temperatures, the log phase was followed, within 200 to 350 days, by a stationary phase, which was monitored until the 550th day of activity. The minimum doubling times ranged from 1 day (5°C) to 20 days (−10°C) to ca. 160 days (−20°C). The curves reached the stationary phase at different levels, depending on the incubation temperature. We suggest that the stationary phase, which is generally considered to be reached when the availability of nutrients becomes limiting, was brought on under our conditions by the formation of diffusion barriers in the thin layers of unfrozen water known to be present in permafrost soils, the thickness of which depends on temperature.”
Citation: E. M. Rivkina, E. I. Friedmann, C. P. McKay, D. A. Gilichinsky, Appl. Environ. Microbiol. August 2000 vol. 66 no. 8 3230-3233, doi: 10.1128/AEM.66.8.3230-3233.2000.

Hygienic problems in using permafrost soils for organic waste disposal (Bölter & Höller, 1999) [FULL TEXT]
Abstract: “This paper reviews the risks on hygienic problems in the northern environments by reindeer slaughter and related waste disposals. Such risks are evident from anticipated possible changes in the socio-economic structure in this region and changes in land use and animal keeping. There are several problems going along with different pathogens and their infection ways. Precautions have to be taken especially for those organisms which can live for long times under dormant stages or which form spores.”
Citation: Manfred Bölter, Christiane Höller, Polarforschung 66 (1/2),61 – 65,1996 (erschienen 1999).

Characterization of Viable Bacteria from Siberian Permafrost by 16S rDNA Sequencing (Shi et al. 1997) [FULL TEXT]
Abstract: “Viable bacteria were found in permafrost core samples from the Kolyma-Indigirka lowland of northeast Siberia. The samples were obtained at different depths; the deepest was about 3 million years old. The average temperature of the permafrost is −10°C. Twenty-nine bacterial isolates were characterized by 16S rDNA sequencing and phylogenetic analysis, cell morphology, Gram staining, endospore formation, and growth at 30°C. The majority of the bacterial isolates were rod shaped and grew well at 30°C; but two of them did not grow at or above 28°C, and had optimum growth temperatures around 20°C. Thirty percent of the isolates could form endospores. Phylogenetic analysis revealed that the isolates fell into four categories: high-GC Gram-positive bacteria, β-proteobacteria, γ-proteobacteria, and low-GC Gram-positive bacteria. Most high-GC Gram-positive bacteria and β-proteobacteria, and all γ-proteobacteria, came from samples with an estimated age of 1.8–3.0 million years (Olyor suite). Most low-GC Gram-positive bacteria came from samples with an estimated age of 5,000–8,000 years (Alas suite).”
Citation: Shi, T., Reeves, R., Gilichinsky, D. et al. Microb Ecol (1997) 33: 169. doi:10.1007/s002489900019.

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New research – carbon cycle (September 12, 2016)

Posted by Ari Jokimäki on September 12, 2016

Some of the latest papers on carbon cycle are shown below. First a few highlighted papers with abstracts and then a list of some other papers. If this subject interests you, be sure to check also the other papers – they are by no means less interesting than the highlighted ones.

Highlights

Methane emissions proportional to permafrost carbon thawed in Arctic lakes since the 1950s (Anthony et al. 2016) http://www.nature.com/ngeo/journal/vaop/ncurrent/full/ngeo2795.html

Abstract: Permafrost thaw exposes previously frozen soil organic matter to microbial decomposition. This process generates methane and carbon dioxide, and thereby fuels a positive feedback process that leads to further warming and thaw. Despite widespread permafrost degradation during the past ~40 years, the degree to which permafrost thaw may be contributing to a feedback between warming and thaw in recent decades is not well understood. Radiocarbon evidence of modern emissions of ancient permafrost carbon is also sparse. Here we combine radiocarbon dating of lake bubble trace-gas methane (113 measurements) and soil organic carbon (289 measurements) for lakes in Alaska, Canada, Sweden and Siberia with numerical modelling of thaw and remote sensing of thermokarst shore expansion. Methane emissions from thermokarst areas of lakes that have expanded over the past 60 years were directly proportional to the mass of soil carbon inputs to the lakes from the erosion of thawing permafrost. Radiocarbon dating indicates that methane age from lakes is nearly identical to the age of permafrost soil carbon thawing around them. Based on this evidence of landscape-scale permafrost carbon feedback, we estimate that 0.2 to 2.5 Pg permafrost carbon was released as methane and carbon dioxide in thermokarst expansion zones of pan-Arctic lakes during the past 60 years.

Rising Plant-mediated Methane Emissions from Arctic Wetlands (Andresen et al. 2016) http://onlinelibrary.wiley.com/doi/10.1111/gcb.13469/abstract

Abstract: Plant-mediated CH4 flux is an important pathway for land-atmosphere CH4 emissions but the magnitude, timing, and environmental controls, spanning scales of space and time, remain poorly understood in arctic tundra wetlands, particularly under the long term effects of climate change. CH4 fluxes were measured in situ during peak growing season for the dominant aquatic emergent plants in the Alaskan arctic coastal plain, Carex aquatilis and Arctophila fulva, to assess the magnitude and species-specific controls on CH4 flux. Plant biomass was a strong predictor of A. fulva CH4 flux while water depth and thaw depth were co-predictors for C. aquatilis CH4 flux. We used plant and environmental data from 1971-72 from the historic International Biological Program (IBP) research site near Barrow, Alaska, which we resampled in 2010-13, to quantify changes in plant biomass and thaw depth, and used these to estimate species-specific decadal-scale changes in CH4 fluxes. A ~60% increase in CH4 flux was estimated from the observed plant biomass and thaw depth increases in tundra ponds over the past 40 years. Despite covering only ~5% of the landscape, we estimate that aquatic C. aquatilis and A. fulva account for two-thirds of the total regional CH4 flux of the Barrow Peninsula. The regionally observed increases in plant biomass and active layer thickening over the past 40 years not only have major implications for energy and water balance, but have significantly altered land-atmosphere CH4 emissions for this region, potentially acting as a positive feedback to climate warming.

Enhanced carbon export to the abyssal depths driven by atmosphere dynamics (Pedrosa-Pàmies et al. 2016) http://onlinelibrary.wiley.com/doi/10.1002/2016GL069781/abstract

Abstract: Long-term biogeochemical observations are critical to understand the natural ability of the oceans to fix CO2 into organic carbon and export it to the deep as sinking particles. Here we present results from a 3 year (2010–2013) sediment trap deployment that allowed detecting interannual variations of carbon fluxes beyond 4000 m depth in the Eastern Mediterranean Sea. Anomalous atmospheric conditions triggering strong heat losses in winter–spring 2012 resulted in convective mixing, nutrient uplifting, and a diatom-dominated bloom southeast of Crete. Phytoplankton growth, reinforced by the arrival of nutrients from airborne Etna volcano ash, was the highest in the last decade (satellite-derived Chl a concentrations up to 1.9 mg m−3). This situation caused carbon export to increase by 2 orders of magnitude (12.2 mg m−2 d−1) with respect to typical values, which demonstrates how pulses of sinking fresh phytodetritus linked to rare atmospheric processes can episodically impact one of the most oligotrophic environments in the world ocean.

Partitioning uncertainty in ocean carbon uptake projections: Internal variability, emission scenario, and model structure (Lovenduski et al. 2016) http://onlinelibrary.wiley.com/doi/10.1002/2016GB005426/abstract

Abstract: We quantify and isolate the sources of projection uncertainty in annual-mean sea-air CO2 flux over the period 2006–2080 on global and regional scales using output from two sets of ensembles with the Community Earth System Model (CESM) and models participating in the 5th Coupled Model Intercomparison Project (CMIP5). For annual-mean, globally-integrated sea-air CO2 flux, uncertainty grows with prediction lead time and is primarily attributed to uncertainty in emission scenario. At the regional scale of the California Current System, we observe relatively high uncertainty that is nearly constant for all prediction lead times, and is dominated by internal climate variability and model structure, respectively in the CESM and CMIP5 model suites. Analysis of CO2 flux projections over 17 biogeographical biomes reveals a spatially heterogenous pattern of projection uncertainty. On the biome scale, uncertainty is driven by a combination of internal climate variability and model structure, with emission scenario emerging as the dominant source for long projection lead times in both modeling suites.

The sensitivity of soil respiration to soil temperature, moisture, and carbon supply at the global scale (Hursh et al. 2016) http://onlinelibrary.wiley.com/doi/10.1111/gcb.13489/abstract

Abstract: Soil respiration (Rs) is a major pathway by which fixed carbon in the biosphere is returned to the atmosphere, yet there are limits to our ability to predict respiration rates using environmental drivers at the global scale. While temperature, moisture, carbon supply and other site characteristics are known to regulate soil respiration rates at plot scales within certain biomes, quantitative frameworks for evaluating the relative importance of these factors across different biomes and at the global scale require tests of the relationships between field estimates and global climatic data. This study evaluates the factors driving Rs at the global scale by linking global datasets of soil moisture, soil temperature, primary productivity and soil carbon estimates with observations of annual Rs from the Global Soil Respiration Database (SRDB). We find that calibrating models with parabolic soil moisture functions can improve predictive power over similar models with asymptotic functions of mean annual precipitation. Soil temperature is comparable with previously-reported air temperature observations used in predicting Rs, and is the dominant driver of Rs in global models; however, within certain biomes soil moisture or soil carbon emerge as dominant predictors of Rs. We identify regions where typical temperature-driven responses are further mediated by soil moisture, precipitation, and carbon supply and regions in which environmental controls on high Rs values are difficult to ascertain due to limited field data. Because soil moisture integrates temperature and precipitation dynamics, it can more directly constrain the heterotrophic component of Rs, but global-scale models tend to smooth its spatial heterogeneity by aggregating factors that increase moisture variability within and across biomes. We compare statistical and mechanistic models that provide independent estimates of global Rs ranging from 83 to 108 Pg/yr, but also highlight regions of uncertainty where more observations are required or environmental controls are hard to constrain.

Other papers

Methane and carbon dioxide fluxes of a temperate mire in Central Europe (Fortuniak et al. 2016) http://www.sciencedirect.com/science/article/pii/S0168192316303781

Airborne methane remote measurements reveal heavy-tail flux distribution in Four Corners region (Frankenberg et al. 2016) http://www.pnas.org/content/113/35/9734.short

Greenhouse gas emissions from natural ecosystems and agricultural lands in sub-Saharan Africa: synthesis of available data and suggestions for further research (Kim et al. 2016) http://www.biogeosciences.net/13/4789/2016/

Peak season carbon exchange shifts from a sink to a source following 50+ years of herbivore exclusion in an Arctic tundra ecosystem (Lara et al. 2016) http://onlinelibrary.wiley.com/doi/10.1111/1365-2745.12654/abstract

Vegetation carbon sequestration in Chinese forests from 2010 to 2050 (He et al. 2016) http://onlinelibrary.wiley.com/doi/10.1111/gcb.13479/abstract

CH4 concentrations over the Amazon from GOSAT consistent with in situ vertical profile data (Webb et al. 2016) http://onlinelibrary.wiley.com/doi/10.1002/2016JD025263/abstract

CH4 exchanges of the natural ecosystems in China during the past three decades: the role of wetland extent and its dynamics (Wei & Wang, 2016) http://onlinelibrary.wiley.com/doi/10.1002/2016JG003418/abstract

Mesoscale modulation of air-sea CO2 flux in Drake Passage (Song et al. 2016) http://onlinelibrary.wiley.com/doi/10.1002/2016JC011714/abstract

Biomass turnover time in terrestrial ecosystems halved by land use (Erb et al. 2016) http://www.nature.com/ngeo/journal/vaop/ncurrent/full/ngeo2782.html

Permafrost carbon as a missing link to explain CO 2 changes during the last deglaciation (Crichton et al. 2016) http://www.nature.com/ngeo/journal/vaop/ncurrent/full/ngeo2793.html

High export via small particles before the onset of the North Atlantic spring bloom (Giering et al. 2016) http://onlinelibrary.wiley.com/doi/10.1002/2016JC012048/abstract

Inorganic carbon cycling and biogeochemical processes in an Arctic inland sea (Hudson Bay) (Burt et al. 2016) http://www.biogeosciences.net/13/4659/2016/

Constrained partitioning of autotrophic and heterotrophic respiration reduces model uncertainties of forest ecosystem carbon fluxes but not stocks (Carbone et al. 2016) http://onlinelibrary.wiley.com/doi/10.1002/2016JG003386/abstract

Century-long increasing trend and variability of dissolved organic carbon export from the Mississippi River basin driven by natural and anthropogenic forcing (Ren et al. 2016) http://onlinelibrary.wiley.com/doi/10.1002/2016GB005395/abstract

Apparent winter CO2 uptake by a boreal forest due to decoupling (Jocher et al. 2016) http://www.sciencedirect.com/science/article/pii/S0168192316303495

Over-estimating climate warming-induced methane gas escape from the seafloor by neglecting multi-phase flow dynamics (Stranne et al. 2016) http://onlinelibrary.wiley.com/doi/10.1002/2016GL070049/abstract

Strong regional atmospheric 14C signature of respired CO2 observed from a tall tower over the mid-western United States (LaFranchi et al. 2016) http://onlinelibrary.wiley.com/doi/10.1002/2015JG003271/abstract

Underestimation of boreal soil carbon stocks by mathematical soil carbon models linked to soil nutrient status (Ťupek et al. 2016) http://www.biogeosciences.net/13/4439/2016/

Methane Emissions from global rice fields: Magnitude, spatio-temporal patterns and environmental controls (Zhang et al. 2016) http://onlinelibrary.wiley.com/doi/10.1002/2016GB005381/abstract

Modeling pCO2 variability in the Gulf of Mexico (Xue et al. 2016) http://www.biogeosciences.net/13/4359/2016/

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