Warmer climate: less or more snow?
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Changes in snow amount, as measured by the water equivalent of the snow pack (SWE), are studied using simulations of 21st century climate by 20 global climate models. Although the simulated warming makes snow season to shorten from its both ends in all of Eurasia and North America, SWE at the height of the winter generally increases in the coldest areas. Elsewhere, snow decreases throughout the winter. The average borderline between increasing and decreasing midwinter SWE coincides broadly with the −20°C isotherm in late 20th century November–March mean temperature, although with some variability between different areas. On the colder side of this isotherm, an increase in total precipitation generally dominates over reduced fraction of solid precipitation and more efficient melting, and SWE therefore increases. On the warmer side, where the phase of winter precipitation and snowmelt are more sensitive to the simulated warming, the reverse happens. The strong temperature dependence of the simulated SWE changes suggests that projections of SWE change could be potentially improved by taking into account biases in simulated present-day winter temperatures. A probabilistic cross verification exercise supports this suggestion.
KeywordsClimate change Climate projection Snow Snow water equivalent Snow depth
We acknowledge the modeling groups for making their model output available as part of the WCRP’s CMIP3 multi-model dataset, the Program for Climate Model Diagnosis and Intercomparison (PCMDI) for collecting and archiving this data, and the WCRP’s Working Group on Coupled Modelling (WGCM) for organizing the model data analysis activity. The WCRP CMIP3 multi-model dataset is supported by the Office of Science, US Department of Energy. This paper benefited from the constructive comments of two anonymous reviewers.
- ACIA (2005) Arctic climate impact assessment: scientific report. Cambridge University Press, London, p 1042Google Scholar
- Christensen JH, Hewitson B, Busuioc A, Chen A, Gao X, Held I, Jones R, Kwon W-T, Laprise R, Magaña Rueda V, Mearns L, Menéndez CG, Räisänen J, Rinke A, Kolli RK, Sarr A, Whetton P (2007) Regional climate projections. In: Solomon S et al (eds) Climate change 2007: the physical science basis. Cambridge University Press, London, pp 847–940Google Scholar
- Foster D, Davy R (1988) Global snow depth climatology. USAF Publ. USAFETAC/TN-88/006, Scott Air Force Base, Illinois, p 48Google Scholar
- Krenke A (1998) Former Soviet Union hydrological snow surveys, 1966–1996. Edited by NSIDC. National Snow and Ice Data Center/World Data Center for Glaciology, Digital media, BoulderGoogle Scholar
- Lemke P, Ren J, Alley R, Allison I, Carrasco J, Flato G, Fujii Y, Kaser G, Mote P, Thomas R, Zhang T (2007) Observations: changes in snow, ice and frozen ground. In: Solomon S et al (eds) Climate change 2007: the physical science basis. Cambridge University Press, London, pp 337–383Google Scholar
- Meehl GA, Stocker TF, Collins W, Friedlingstein P, Gaye A, Gregory J, Kitoh A, Knutti R, Murphy J, Noda A, Raper S, Watterson I, Weaver A, Zhao Z-C (2007) Global climate projections. In: Solomon S et al (eds) Climate change 2007: the physical science basis. Cambridge University Press, London, pp 747–845Google Scholar
- Nakićenović N, Swart R, Eds. (2000) Emission Scenarios. A special report of Working Group III of the Intergovernmental Panel on Climate Change. Cambridge University Press, London, p 599Google Scholar
- Räisänen J, Ruokolainen L (2006) Probabilistic forecasts of near-term climate change based on a resampling ensemble technique. Tellus 58A:461–472Google Scholar
- Randall DA, Wood RA, Bony S, Colman R, Fichefet T, Fyfe J, Kattsov V, Pitman A, Shukla J, Srinivasan J, Stouffer RJ, Sumi A, Taylor KE (2007) Climate models and their evaluation. In: Solomon S et al (eds) Climate change 2007: the physical science basis. Cambridge University Press, London, pp 589–662Google Scholar
- Scherrer SC, Appenzeller C, Laternser M (2004) Trends in Swiss alpine snow days––the role of local and large-scale climate variability. Geophys Res Lett 31, doi:10.1029/2004GL020255Google Scholar
- Wilks DS (1995) Statistical methods in the atmospheric Sciences. Academic, New york, p 467Google Scholar