New research – temperature (July 26, 2016)
Posted by Ari Jokimäki on July 26, 2016
Some of the latest papers on temperature 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.
The rogue nature of hiatuses in a global warming climate (Sévellec, Sinha & Skliris, 2016)
Abstract: The nature of rogue events is their unlikelihood and the recent unpredicted decade-long slowdown in surface warming, the so-called hiatus, may be such an event. However, given decadal variability in climate, global surface temperatures were never expected to increase monotonically with increasing radiative forcing. Here, surface air temperature from twenty climate models is analysed to estimate the historical and future likelihood of hiatuses and “surges” (faster than expected warming), showing that the global hiatus of the early 21st Century was extremely unlikely. A novel analysis of future climate scenarios suggests that hiatuses will almost vanish and surges will strongly intensify by 2100 under a “business as usual” scenario. For “CO2 stabilisation” scenarios, hiatus and surge characteristics revert to typical 1940s values. These results suggest to study the hiatus of the early 21st Century and future re-occurrences as rogue events, at the limit of the variability of current climate modelling capability.
Underestimated warming of northern Canada in the Berkeley Earth temperature product (Way, Oliva & Viau, 2016)
Abstract: The Berkeley Earth surface temperature (BERK) project provides gridded global temperature anomaly products using an automated geostatistical approach to adjust station data for systematic biases. Despite its widespread usage, the BERK data set has not been evaluated at the national-scale, especially in data-sparse high latitude environments. This study provides an evaluation of the BERK product across all of Canada using 333 climate stations made available from the homogenized Environment Canada station network (HTcan). Comparison between co-located monthly air temperature anomalies for the two data sets suggests small differences between the two products for mean surface (∼2 m) air temperature. However, the relatively minimal bias in mean temperature is a consequence of contrasting cold and warm biases in minimum and maximum air temperatures, respectively, that are larger but effectively even out when averaged together. The BERK product is shown to exhibit systematic underestimation of recent regional warming in northern Canada which when combined with an overestimation of warmth earlier in the record results in an observable reduction in warming rates for minimum and mean temperature anomalies since 1950. The temporal evolution and spatial pattern of the observed biases suggest that the BERK-automated adjustments to station data in northern Canada miss some inhomogeneities in the raw station data. These results highlight the need for enhanced data recovery and homogenization efforts in data-sparse high latitude regions and emphasize the importance of national-scale climate data sets for evaluating global gridded products. We also recommend caution when using the BERK minimum and maximum monthly air temperature products for long-term trend analyses.
Revisiting whether recent surface temperature trends agree with the CMIP5 ensemble (Lin & Huybers, 2016)
Abstract: A weaker trend in global mean temperature over the past 15 years relative to the preceding decades has been characterized as significantly lower than those contained within the CMIP5 ensemble. In this study, divergence between model simulations and observations is estimated using a fixed-intercept linear trend with a slope estimator that has one-third the noise variance compared to simple linear regression. Following the approach of Fyfe et al. (2013) where inter-model spread is used to assess the distribution of trends, but using the fixed-intercept trend metric, demonstrates that recently observed trends in global-mean temperature are consistent (p > 0.1) with the CMIP5 ensemble for all 15-year intervals of observation-model divergence since 1970. Significant clustering of global trends according to modeling center indicates that the spread in CMIP5 trends is better characterized using ensemble members drawn across models, as opposed to using ensemble members from a single model. Despite model-observation consistency at the global level, substantial regional discrepancies in surface temperature trends remain.
Climate change in the Kola Peninsula, Arctic Russia, during the last 50 years from meteorological observations (Marshall, Vignols & Rees, 2016)
Abstract: We provide a detailed climatology and evaluation of recent climate change in the Kola Peninsula, Arctic Russia, a region influenced by both the North Atlantic and Arctic Oceans. The analysis is based on 50 years of monthly surface air temperature (SAT), precipitation (PPN) and sea level pressure (SLP) data from ten meteorological stations for 1966-2015. Regional mean annual SAT is ~0°C: the moderating effect of the ocean is such that coastal (inland) stations have a positive (negative) value. Examined mean annual PPN totals rise from ~430 mm in the north-east of the region to ~600 mm in the west.
Annual SAT in the Kola Peninsula has increased by 2.3 ± 1.0 °C over the past 50 years. Seasonally, statistically significant warming has taken place in spring and fall, although the largest trend has occurred in winter. While there has been no significant change in annual PPN, spring has become significantly wetter and fall drier. The former is associated with the only significant seasonal SLP trend (decrease). A positive winter North Atlantic Oscillation (NAO) index is generally associated with a warmer and wetter Kola Peninsula while a positive Siberian High (SH) index has the opposite impact. The relationship between both the NAO and SH and SAT is broadly coherent across the region whereas their relationship with PPN varies markedly, although none of the relationships are temporally invariant. Reduced sea ice in the Barents and White Seas and associated circulation changes are likely to be the principal drivers behind the observed changes.
Water temperature increases in the river Rhine in response to climate change (Hardenbicker et al. 2016)
Abstract: The present study analyzes climate change effects on the water temperature of the Rhine, one of the largest rivers in Central Europe. Simulation calculations were performed based on a range of climate and river flow projections for the near (2021–2050) and for the far future (2071–2100) compared to a reference period (1961–1990). Changes in mean annual water temperature in the near future range between +0.6 and +1.4 °C and between +1.9 and +2.2 °C in the far future (average of nine stations). Monthly mean values of the far future change in a more differentiated way by +0.4 to +1.3 °C in spring and +2.7 to +3.4 °C in late summer. The length of periods of high water temperature, expressed as successive days with water temperatures over 27 °C, increases by a factor of four until 2100. These prolonged durations of periods with unusually high water temperatures may provoke changes in the food web and in the rates of biological processes in the Rhine.
Assessing the uncertainty of CESM-LE in simulating the trends of mean and extreme temperature and precipitation over China (Li, Zhu & Dong, 2016)
Reconciling Observed and Modelled Temperature and Precipitation Trends over Europe by Adjusting for Circulation Variability (Saffioti et al. 2016)
Geo-spatial analysis of temporal trends of temperature and its extremes over India using daily gridded (1°×1°) temperature data of 1969–2005 (Chakraborty et al. 2016)
Sudden stratospheric warmings observed in the last decade by satellite measurements (Kishore et al. 2016)
Longitudinal Asymmetric Trends of Tropical Cold-point Tropopause Temperature and Their Link to Strengthened Walker Circulation (Hu et al. 2016)
An in situ-based analysis of the relationship between land surface ‘skin’ and screen-level air temperatures (Good, 2016)
Spatiotemporal rainfall and temperature trends throughout the Brazilian Legal Amazon, 1973–2013 (Almeida et al. 2016)
Spatial variation of deterministic chaos in mean daily temperature and rainfall over Nigeria (Fuwape et al. 2016)
Homogenisation of temperature and precipitation time series with ACMANT3: method description and efficiency tests (Domonkos & Coll, 2016)
The tropical Pacific as a key pacemaker of the variable rates of global warming (Kosaka & Xie, 2016)
The changing shape of Northern Hemisphere summer temperature distributions (McKinnon et al. 2016)
Future Decreases in Freezing Days Across North America (Rawlins et al. 2016)
Arctic warming, moisture increase and circulation changes observed in the Ny-Ålesund homogenized radiosonde record (Maturilli & Kayser, 2016)
Trend analysis of air temperature time series in Greece and their relationship with circulation using surface and satellite data: recent trends and an update to 2013 (Feidas, 2016)
Urban Heat Island traverses in the City of Adelaide, South Australia (Clay et al. 2016)
Recent Extreme Arctic Temperatures are due to a Split Polar Vortex (Overland & Wang, 2016)
Potential tropical Atlantic impacts on Pacific decadal climate trends (Chikamoto et al. 2016)
Consistent land surface temperature data generation from irregularly spaced Landsat imagery (Fu & Weng, 2016)
Spatial and temporal variation in daily temperature indices in summer and winter seasons over India (1969–2012) (Kumar et al. 2016)
Spatial patterns of recent Antarctic surface temperature trends and the importance of natural variability: lessons from multiple reconstructions and the CMIP5 models (Smith & Polvani, 2016)
From Urban to National Heat Island: the effect of anthropogenic heat output on climate change in high population industrial countries (Murray & Heggie, 2016)
From accelerated warming to warming hiatus in China (Xie, Huang & Liu, 2016)
Weekly cycles in peak time temperatures and urban heat island intensity (Earl, Simmonds & Tapper, 2016)
Radiative and Dynamical Influences on Polar Stratospheric Temperature Trends (Ivy, Solomon & Rieder, 2016)