AGW Observer

Observations of anthropogenic global warming

New research – climate change impacts on cryosphere (July 23, 2016)

Posted by Ari Jokimäki on July 23, 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.


Antarctic sea-ice expansion between 2000 and 2014 driven by tropical Pacific decadal climate variability

Abstract: Antarctic sea-ice extent has been slowly increasing in the satellite record that began in 1979. Since the late 1990s, the increase has accelerated, but the average of all climate models shows a decline. Meanwhile, the Interdecadal Pacific Oscillation, an internally generated mode of climate variability, transitioned from positive to negative, with an average cooling of tropical Pacific sea surface temperatures, a slowdown of the global warming trend and a deepening of the Amundsen Sea Low near Antarctica that has contributed to regional circulation changes in the Ross Sea region and expansion of sea ice. Here we show that the negative phase of the Interdecadal Pacific Oscillation in global coupled climate models is characterized by anomalies similar to the observed sea-level pressure and near-surface 850 hPa wind changes near Antarctica since 2000 that are conducive to expanding Antarctic sea-ice extent, particularly in the Ross Sea region in all seasons, involving a deepening of the Amundsen Sea Low. These atmospheric circulation changes are shown to be mainly driven by precipitation and convective heating anomalies related to the Interdecadal Pacific Oscillation in the equatorial eastern Pacific, with additional contributions from convective heating anomalies in the South Pacific convergence zone and tropical Atlantic regions.

Million year old ice found under meter thick debris layer in Antarctica

Abstract: Cosmogenic nuclide measurements associated with buried glacier ice in Ong Valley, in the Transantarctic Mountains, suggest the preservation of ancient ice. There are three glacial tills on the valley floor which have formed from the concentration of regolith contained within sublimating glacier ice. Two tills are less than 1 m thick and underlain by ice. Measurements of cosmogenic 10Be, 26Al, and 21Ne show that (i) the youngest buried ice unit and corresponding till are at least 11–13 ka, (ii) another ice unit and corresponding intermediate-age till are at least 1.1 Ma old under any circumstances and most likely older than 1.78 Ma, and (iii) the oldest till is at least 1.57 Ma and most likely greater than 2.63 Ma. These observations highlight the longevity of ice under thin debris layers and the potential to sample ancient ice for paleoclimate/paleoatmosphere information close to the present land surface.

Accelerating retreat and high-elevation thinning of glaciers in central Spitsbergen

Abstract: Svalbard is a heavily glacier-covered archipelago in the Arctic. Dickson Land (DL), in the central part of the largest island, Spitsbergen, is relatively arid and, as a result, glaciers there are relatively small and restricted mostly to valleys and cirques. This study presents a comprehensive analysis of glacier changes in DL based on inventories compiled from topographic maps and digital elevation models for the Little Ice Age (LIA) maximum, the 1960s, 1990, and 2009/2011. Total glacier area has decreased by  ∼ 38 % since the LIA maximum, and front retreat increased over the study period. Recently, most of the local glaciers have been consistently thinning in all elevation bands, in contrast to larger Svalbard ice masses which remain closer to balance. The mean 1990–2009/2011 geodetic mass balance of glaciers in DL is among the most negative from the Svalbard regional means known from the literature.

The Andes Cordillera. Part I: snow distribution, properties, and trends (1979–2014)

Abstract: Snow cover presence, duration, properties, and water amount play a major role in Earth’s climate system through its impact on the surface energy budget. Snow cover conditions and trends (1979–2014) were simulated for South America – for the entire Andes Cordillera. Recent data sets and SnowModel developments allow relatively high-resolutions of 3-h time step and 4-km horizontal grid increment for this domain. US Geological Survey’s Global Multi-resolution Terrain Elevation Data 2010 topography, Global Land Cover (GlobCover), Randolph Glacier Inventory (v. 4.0) glacier, and NASA modern-era retrospective analysis for research and applications data sets were used to simulate first-order atmospheric forcing (e.g. near-surface air temperature and precipitation, including the fraction of precipitation falling as snow) and terrestrial snow characteristics (e.g. snow cover days, snow water equivalent depth, and snow density). Simulated snow conditions were verified against moderate-resolution imaging spectroradiometer-derived snow cover extent and 3064 individual direct observations of snow depths. Regional variability in mean annual air temperature occurred: positive trends in general were seen in the high Andes Cordillera, and negative trends at relatively lower elevations both east and west of the Cordillera. Snow precipitation showed more heterogeneous patterns than air temperature due to the influence from atmospheric conditions, topography, and orography. Overall, for the Cordillera, much of the area north of 23°S had a decrease in the number of snow cover days, while the southern half experienced the opposite. The snow cover extent changed ∼−15% during the simulation period, mostly between the elevations of ∼3000 and 5000 m above sea level (a.s.l.). However, below 1000 m a.s.l. (in Patagonia) the snow cover extent increased. The snow properties varied over short distances both along and across the Andes Cordillera.

Greenland Ice Sheet seasonal and spatial mass variability from model simulations and GRACE (2003–2012)

Abstract: Improving the ability of regional climate models (RCMs) and ice sheet models (ISMs) to simulate spatiotemporal variations in the mass of the Greenland Ice Sheet (GrIS) is crucial for prediction of future sea level rise. While several studies have examined recent trends in GrIS mass loss, studies focusing on mass variations at sub-annual and sub-basin-wide scales are still lacking. At these scales, processes responsible for mass change are less well understood and modeled, and could potentially play an important role in future GrIS mass change. Here, we examine spatiotemporal variations in mass over the GrIS derived from the Gravity Recovery and Climate Experiment (GRACE) satellites for the January 2003–December 2012 period using a “mascon” approach, with a nominal spatial resolution of 100 km, and a temporal resolution of 10 days. We compare GRACE-estimated mass variations against those simulated by the Modèle Atmosphérique Régionale (MAR) RCM and the Ice Sheet System Model (ISSM). In order to properly compare spatial and temporal variations in GrIS mass from GRACE with model outputs, we find it necessary to spatially and temporally filter model results to reproduce leakage of mass inherent in the GRACE solution. Both modeled and satellite-derived results point to a decline (of −178.9 ± 4.4 and −239.4 ± 7.7 Gt yr−1 respectively) in GrIS mass over the period examined, but the models appear to underestimate the rate of mass loss, especially in areas below 2000 m in elevation, where the majority of recent GrIS mass loss is occurring. On an ice-sheet-wide scale, the timing of the modeled seasonal cycle of cumulative mass (driven by summer mass loss) agrees with the GRACE-derived seasonal cycle, within limits of uncertainty from the GRACE solution. However, on sub-ice-sheet-wide scales, some areas exhibit significant differences in the timing of peaks in the annual cycle of mass change. At these scales, model biases, or processes not accounted for by models related to ice dynamics or hydrology, may lead to the observed differences. This highlights the need for further evaluation of modeled processes at regional and seasonal scales, and further study of ice sheet processes not accounted for, such as the role of subglacial hydrology in variations in glacial flow.

Other papers

The effects of Antarctic iceberg calving-size distribution in a global climate model

Emerging impact of Greenland meltwater on deepwater formation in the North Atlantic Ocean

Glacial Isostatic Adjustment (GIA) in Greenland: a Review

Long-term changes of glaciers in north-western Spitsbergen

Twelve-year cyclic surging episodes at Donjek Glacier in Yukon, Canada

Glacier melting and precipitation trends detected by surface area changes in Himalayan ponds

Effects of sources, transport and post-depositional processes on levoglucosan records in southeastern Tibetan glaciers

A global assessment of the societal impacts of glacier outburst floods

Interaction of sea ice floe size, ocean eddies and sea ice melting

Arctic sea ice decline contributes to thinning lake ice trend in northern Alaska

Predictability of Arctic annual minimum sea ice patterns

Changes in summer sea ice, albedo, and portioning of surface solar radiation in the Pacific sector of Arctic Ocean during 1982-2009

Patterns of Sea-Ice Retreat in the Transition to a Seasonally Ice-Free Arctic

Sea ice leads in the Arctic Ocean: Model assessment, interannual variability and trends

Atmospheric winter response to Arctic sea ice changes in reanalysis data and model simulations

The Role of Ocean Heat Transport in the Global Climate Response to Projected Arctic Sea Ice Loss

The Role of Springtime Arctic Clouds in Determining Autumn Sea Ice Extent

Linkages between Arctic summer circulation regimes and regional sea ice anomalies

Water-mass transformation by sea ice in the upper branch of the Southern Ocean overturning

A review of recent changes in Southern Ocean sea ice, their drivers and forcings

About the consistency between Envisat and CryoSat-2 radar freeboard retrieval over Antarctic sea ice

Monitoring surface deformation over permafrost with an improved SBAS-InSAR algorithm: With emphasis on climatic factors modeling

Permafrost Meta-Omics and Climate Change

Carbon loss and chemical changes from permafrost collapse in the northern Tibetan Plateau

The Effects of Climate Change on Seasonal Snowpack and the Hydrology of the Northeastern and Upper Midwest, U.S.

Characterizing the extreme 2015 snowpack deficit in the Sierra Nevada (USA) and the implications for drought recovery

Effect of snow grain shape on snow albedo

The Andes Cordillera. Part II: Rio Olivares Basin snow conditions (1979–2014), central Chile

Design of a scanning laser meter for monitoring the spatio-temporal evolution of snow depth and its application in the Alps and in Antarctica

Decreasing Spatial Dependence in Extreme Snowfall in the French Alps since 1958 under Climate Change

A snow climatology of the Andes Mountains from MODIS snow cover data

Spatiotemporal Snowfall Variability in the Lake Michigan Region: How is Warming Affecting Wintertime Snowfall?

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