基于快速多维经验模态分解的北半球冬季近地表气温和积雪覆盖频率变化趋势提取  

Untangling of northern midaltitude near surface air temperature and snow cover frequency trends with multidimensional ensemble empirical mode decomposition

作　　者：刘权 姚凤梅 LIU Quan;YAO Fengmei(College of Earth and Planetary Sciences,University of Chinese Academy of Sciences,Beijing 100049,China)

机构地区：[1]中国科学院大学地球与行星科学学院,北京100049

出　　处：《中国科学院大学学报（中英文）》2023年第2期191-202,共12页Journal of University of Chinese Academy of Sciences

基　　金：中国科学院先导专项(No.XDA19030402);国家自然科学基金(42071425)资助。

摘　　要：北极正在以全球平均水平2倍的速度变暖,而北半球中纬度冬季出现明显的变冷趋势。这种异常的气候模式受到广泛关注。使用改进的快速多维经验模态分解方法,提取北半球中纬度近地表气温和积雪覆盖频率的长期趋势和变化率。从累积变化趋势来看,自1990年代开始,亚欧大陆中部地区变冷,西伯利亚高压增强,积雪覆盖频率增大;但从变化速率来看,欧亚大陆中部的快速变冷和积雪覆盖频率的快速增加主要发生在1990—2000年代,之后变率趋缓。因此,随着变化率进一步降低,北半球中纬度冬季的快速变冷可能发展为一个短期而非长期趋势。本研究展示的近地表气温和积雪覆盖频率趋势的演化过程,对探究北半球中纬度变冷的成因有重要意义。The Arctic has warmed more rapidly than the globe as a whole,while the northern midlatitudes have experienced more frequent severe winters.The anomalous climate pattern has drawn wide attentions.Here we improved the method fast multidimensional ensemble empirical mode decomposition(Fast-MEEMD)to extract the long-term trends of near surface air temperature(SAT)and snow cover frequency(SCF).The results show evident“warming arctic-cooling continent(WACC)”pattern.From the perspective of cumulative change,SAT over central Eurasia has decreased,the Siberia High has amplified and the SCF over Eastern Asian has increased since 1990s.while in term of changing rate,this accelerated cooling tendency over midlatitudes is mainly occurred between 1990s-2000s.Therefore,the cooling trends may develop as short rather than long-term trends.The study provides new materials to evaluate the roles of other factors in driving midlatitudes cooling.

关 键 词：近地表气温 积雪覆盖频率 快速多维经验模态分解 

分 类 号：P467[天文地球—大气科学及气象学]