An analysis of present and future seasonal Northern Hemisphere land snow cover simulated by CMIP5 coupled climate models

Abstract

Abstract. The 20th century seasonal Northern Hemisphere (NH) land snow cover as simulated by available CMIP5 model output is compared to observations. On average, the models reproduce the observed snow cover extent very well, but the significant trend towards a reduced spring snow cover extent over the 1979-2005 period is underestimated (observed: (−3.4 ± 1.1) % per decade; simulated: (−1.0 ± 0.3) % per decade). We show that this is linked to the simulated Northern Hemisphere extratropical spring land warming trend over the same period, which is also underestimated, although the models, on average, correctly capture the observed global warming trend. There is a good linear correlation between the extent of hemispheric seasonal spring snow cover and boreal large-scale spring surface air temperature in the models, supported by available observations. This relationship also persists in the future and is independent of the particular anthropogenic climate forcing scenario. Similarly, the simulated linear relationship between the hemispheric seasonal spring snow cover extent and global mean annual mean surface air temperature is stable in time. However, the slope of this relationship is underestimated at present (observed: (−11.8 ± 2.7) % • C −1 ; simulated: (−5.1 ± 3.0) % • C −1 ) because the trend towards lower snow cover extent is underestimated, while the recent global warming trend is correctly represented.

Evaluation of North Eurasian snow-off dates in the ECHAM5.4 atmospheric general circulation model

“…Recently, Brutel-Vuilmet et al (2013) found that, while there is still substantial intermodel dispersion among the CMIP5 models, on average the springtime snowmelt is slightly delayed in northern Eurasia. Taken at face value, the default version of ECHAM5 agrees with this result for the eastern parts of northern Eurasia, while in the west, snow vanishes too early (Figs.…”

“…These include several intercomparisons of snow conditions simulated by atmospheric and fully coupled general circulation models (GCMs) with observational data (Foster et al, 1996;Frei and Robinson, 1998;Frei et al, 2003Frei et al, , 2005Roesch, 2006;Derksen and Brown, 2012;Brutel-Vuilmet et al, 2013). Most recently, Brutel-Vuilmet et al (2013) evaluated the snow cover simulated by models participating in Phase 5 of the Coupled Model Intercomparison Project (CMIP5).…”

“…Derksen and Brown (2012) further demonstrated, for a subset of eight CMIP5 models, that the models failed to capture the rapid decline in Northern Hemisphere late spring (May-June) snow cover observed in 2008-2012. Regarding the reasons for biases in modelled snow conditions, the intercomparison studies have, in general, not been very conclusive. Most attention has been paid to biases in simulated air temperature (Foster et al, 1996;Räisänen, 2008) and total precipitation or snowfall (Foster et al, 1996;Roesch, 2006;Brutel-Vuilmet et al, 2013). Frei et al (2005) further suggested that the exclusion of subgrid-scale treatments for terrain and land cover contributed to overestimated ablation rate of snow in spring over North America in AMIP2 models.…”

Assessment of Snow, Sea Ice, and Related Climate Processes in Canada's Earth-System Model and Climate Prediction System

“…A standard target for snow process analysis in climate models is snow-cover extent trends, which are strongly temperature 25 controlled (e.g. Brutel-Vuilmet et al, 2013;Mudryk et al, 2017). Assessing the ability of models to capture these trends needs to account for natural variability, forced variability, observational uncertainty, and intermodel differences.…”

Assessment of Simulations of Snow Depth in the Qinghai-Tibetan Plateau Using CMIP5 Multi-Models

“…Brutel-Vuilmet et al (2013) have compared the 20th century seasonal northern hemisphere land snow cover as simulated by available CMIP5 model output to observations, and the results show that the models reproduce the observed snow cover extent very well on average but the significant trend toward a reduced spring snow cover extent over the 1979-2005 period is underestimated. Zhu and Dong (2013) have pointed out that the CMIP5 coupled models can catch the main distribution characteristics of the observed northern hemisphere March-April snow cover but overestimate the mean snow cover in complex terrain area such as Qinghai-Tibet Plateau.…”