1981~2020年北半球冬季气温变化对降雪量的影响

Impact of Winter Temperature Changes on Snowfall in the Northern Hemisphere from 1981 to 2020

摘要: 全球变暖背景下，北半球冬季气温和降雪量变化对全球气候系统具有重要影响。本文基于CRU和ERA5再分析数据，采用趋势分析、Mann-Kendall突变检验和相关性分析等方法，系统研究了1981~2020年北半球冬季气温和降雪量的时间变化特征及其相互关系。结果表明：(1) 1981~2020年北半球冬季平均气温为0.43℃，呈显著上升趋势(P < 0.05)，变化速率为0.30℃/10a，40年间气温升高约1.2℃，于1996年发生显著突变，突变后气温较突变前升高0.66℃；(2) 北半球年平均降雪量为117.28 mm，呈显著下降趋势(P < 0.05)，变化速率为−2.24 mm/10a，40年间降雪量减少约8.96 mm，同样在1996年发生突变性减少，突变后较突变前减少5.75 mm；(3) 北半球年平均气温与年降雪量呈极显著负相关关系(r = −0.49, P < 0.01)，气温每升高1℃，降雪量平均减少约3.44 mm。研究揭示了全球变暖背景下北半球冬季“暖干化”趋势，气温上升导致降雪量减少，为理解气候变化对北半球冬季降雪的影响机制提供了科学依据。

Abstract: Under the background of global warming, changes in winter temperature and snowfall in the Northern Hemisphere have significant impacts on the global climate system. Based on CRU and ERA5 reanalysis data, this study systematically investigates the temporal variation characteristics of winter temperature and snowfall in the Northern Hemisphere from 1981 to 2020 and their relationship using trend analysis, Mann-Kendall mutation test, and correlation analysis. The results indicate that: (1) The average winter temperature in the Northern Hemisphere from 1981 to 2020 was 0.43˚C, showing a significant upward trend (P < 0.05) with a rate of 0.30˚C/10a. The temperature increased by approximately 1.2˚C over the 40 years, with a significant mutation occurring in 1996. After the mutation, the temperature increased by 0.66˚C compared to the period before the mutation. (2) The average annual snowfall in the Northern Hemisphere was 117.28 mm, showing a significant downward trend (P < 0.05) with a rate of −2.24 mm/10a. Snowfall decreased by approximately 8.96 mm over the 40 years, also experiencing a significant mutation decrease in 1996. After the mutation, snowfall decreased by 5.75 mm compared to the period before the mutation. (3) There is a highly significant negative correlation between the average annual temperature and annual snowfall in the Northern Hemisphere (r = −0.49, P < 0.01). For every 1˚C increase in temperature, snowfall decreases by an average of approximately 3.44 mm. This study reveals a “warming and drying” trend in Northern Hemisphere winters under global warming, where rising temperatures lead to reduced snowfall, providing a scientific basis for understanding the impact mechanism of climate change on winter snowfall in the Northern Hemisphere.