气候变化领域集成服务门户(CCPortal): Future snowfall in the Alps: Projections based on the EURO-CORDEX regional climate models

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DOI	10.5194/tc-12-1-2018
	Future snowfall in the Alps: Projections based on the EURO-CORDEX regional climate models
	Frei P.; Kotlarski S.; Liniger M.A.; Schär C.
发表日期	2018
ISSN	19940416
卷号	12 期号:1
英文摘要	Twenty-first century snowfall changes over the European Alps are assessed based on high-resolution regional climate model (RCM) data made available through the EURO-CORDEX initiative. Fourteen different combinations of global and regional climate models with a target resolution of 12 km and two different emission scenarios are considered. As raw snowfall amounts are not provided by all RCMs, a newly developed method to separate snowfall from total precipitation based on near-surface temperature conditions and accounting for subgrid-scale topographic variability is employed. The evaluation of the simulated snowfall amounts against an observation-based reference indicates the ability of RCMs to capture the main characteristics of the snowfall seasonal cycle and its elevation dependency but also reveals considerable positive biases especially at high elevations. These biases can partly be removed by the application of a dedicated RCM bias adjustment that separately considers temperature and precipitation biases. Snowfall projections reveal a robust signal of decreasing snowfall amounts over most parts of the Alps for both emission scenarios. Domain and multi-model mean decreases in mean September-May snowfall by the end of the century amount to .25 and .45% for representative concentration pathway (RCP) scenarios RCP4.5 and RCP8.5, respectively. Snowfall in low-lying areas in the Alpine forelands could be reduced by more than .80 %. These decreases are driven by the projected warming and are strongly connected to an important decrease in snowfall frequency and snowfall fraction and are also apparent for heavy snowfall events. In contrast, high-elevation regions could experience slight snowfall increases in midwinter for both emission scenarios despite the general decrease in the snowfall fraction. These increases in mean and heavy snowfall can be explained by a general increase in winter precipitation and by the fact that, with increasing temperatures, climatologically cold areas are shifted into a temperature interval which favours higher snowfall intensities. In general, percentage changes in snowfall indices are robust with respect to the RCM postprocessing strategy employed: Similar results are obtained for raw, separated, and separated-bias-adjusted snowfall amounts. Absolute changes, however, can differ among these three methods. © 2018 Author.
语种	英语
来源期刊	Cryosphere
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/119247
作者单位	Institute for Atmospheric and Climate Sciences, ETH Zurich, Zurich, 8006, Switzerland; Federal Office of Meteorology and Climatology, Zurich Airport, 8058, Switzerland
推荐引用方式 GB/T 7714	Frei P.,Kotlarski S.,Liniger M.A.,et al. Future snowfall in the Alps: Projections based on the EURO-CORDEX regional climate models[J],2018,12(1).
APA	Frei P.,Kotlarski S.,Liniger M.A.,&Schär C..(2018).Future snowfall in the Alps: Projections based on the EURO-CORDEX regional climate models.Cryosphere,12(1).
MLA	Frei P.,et al."Future snowfall in the Alps: Projections based on the EURO-CORDEX regional climate models".Cryosphere 12.1(2018).