欧亚大陆春季融雪异常10-30天季节内变化主要特征及其环流异常演变分析  

Analysis for the Main Characteristics of 10-30-day Intraseasonal Variations in Spring Snowmelt Anomalies over Eurasia and Associated Abnormal Circulation Patterns

作　　者：陆聪 陈海山[1,2] 孙悦[1,2] LU Cong;CHEN Haishan;SUN Yue(Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters/Key Laboratory of Meteorological Disaster,Ministry of Education,Nanjing University of Information Science and Technology,Nanjing 210044;School of Atmospheric Sciences,Nanjing University of Information Science and Technology,Nanjing 210044)

机构地区：[1]南京信息工程大学气象灾害预报预警与评估协同创新中心/气象灾害教育部重点实验室,南京210044 [2]南京信息工程大学大气科学学院,南京210044

出　　处：《大气科学》2024年第4期1427-1443,共17页Chinese Journal of Atmospheric Sciences

基　　金：国家自然科学基金项目42088101。

摘　　要：欧亚大陆积雪是影响中高纬气候的重要因子,深入理解该区域积雪异常变化的特征及其成因,对于气候研究和预测有重要意义。目前的研究大多关注积雪年际、年代际变化及其气候效应,而有关积雪季节内变化的认识还有待加强。本文基于观测和再分析资料,通过统计诊断探讨了欧亚大陆不同区域春季融雪的季节内变化及其与之相关的大气环流特征和地表能量演变过程。结果表明,欧亚大陆春季融雪异常具有明显的季节内变化特征,其主导周期为10~30 d,且季节内变化的信号主要出现在斯堪的纳维亚半岛、东欧平原和西西伯利亚三个区域。进一步分析表明,斯堪的纳维亚半岛地区融雪季节内变化可能和斯堪的纳维亚半岛遥相关型负位相(SCA−)有关,东欧平原融雪季节内变化可能和欧亚遥相关型负位相(EU−)有关,西西伯利亚地区融雪季节内变化可能和斯堪的纳维亚半岛遥相关型正位相(SCA+)有关。不同区域导致融雪异常的原因存在明显差异,长波辐射增加可能是斯堪的纳维亚半岛区域开始发生融雪异常的主要原因;而在东欧平原和西西伯利亚区域,感热通量异常可能是开始发生融雪异常的主要原因。Eurasian snow cover significantly influences the climate in the mid-high latitudes.Understanding the characteristics and causes of abnormal changes in Eurasian snow cover is crucial for advancing climate research and improving climate prediction accuracy.While current research has predominantly focused on interannual and interdecadal changes and climatic effects of the snow cover,there is a lack of understanding of its intraseasonal changes.This paper discusses the intraseasonal variation in spring snowmelt across different regions of Eurasia,along with related atmospheric circulation characteristics and surface-energy evolution processes,using observation and reanalysis data through statistical methods.The results reveal that anomalies in the Eurasian spring snowmelt exhibit obvious intraseasonal variation,with a dominant cycle of 10-30 days.Intraseasonal signals mainly appear in the Scandinavian Peninsula,the eastern European Plain,and western Siberia.Further analysis shows that the intraseasonal variation in the spring snowmelt in the Scandinavian Peninsula may be related to the negative phase of the Scandinavian teleconnection(SCA−),while that in the eastern European Plain may be related to the negative phase of the Eurasian teleconnection(EU−).The intraseasonal variation in western Siberia may be related to the positive phase of the Scandinavian teleconnection(SCA+).There are obvious differences in the causes of spring snowmelt anomalies in different regions.In Scandinavia,an increase in long-wave radiation is likely the main cause.Conversely,sensible heat flux anomalies may be the main causes in the eastern European Plain and western Siberia.

关 键 词：春季融雪 季节内变化 大气遥相关 地表能量通量 

分 类 号：P434[天文地球—大气科学及气象学]