New insights from the bias-corrected simulations of CMIP6 in Northern Hemisphere’s snow drought
摘要
Recent decades have witnessed increasing snow droughts in the Northern Hemisphere, yet reliable future projections remain challenging due to biases in climate models. This study employs a Cumulative Distribution Function-transform bias correction method to refine Snow Water Equivalent outputs from 29 CMIP6 models, enabling a robust assessment of future snow drought characteristics using the Snow Water Equivalent Index. Our analysis reveals a fundamental structural shift in snow drought regimes under high-emission scenarios. While the frequency and duration of less severe droughts may stabilize or even decline, the most extreme droughts intensify dramatically—becoming more frequent, prolonged, and severe. This escalation is strongly tied to emission levels, with the SSP585 scenario projecting a 54.5% increase in duration and a six-fold rise in intensification trends compared to sustainable pathways. Spatially, hotspots emerge across Europe, western Asia, and central North America. These findings underscore the critical need for rapid emission reductions to mitigate escalating snow drought risks and their profound implications for water resources, ecosystems, and socioeconomic stability.