吉林省扶余市短时内接连两次暴雪过程对比分析

Comparative Analysis of Two Consecutive Snowstorm Events in Fuyu County, Jilin Province

摘要: 本文基于吉林省扶余市2023年11月6日和11月8日两次降雪过程的逐小时观测资料、ERA5与GDAS再分析数据，结合HYSPLIT后向轨迹模型和水汽收支诊断方法，探讨两次降雪过程的水汽输送特征及动力–水汽配置差异。结果表明，11月6日强暴雪过程累计降雪量达16.6 cm，受高纬冷湿气流与海洋暖湿水汽共同影响，500 hPa层西北冷湿输送明显，700 hPa层日本海暖湿气流持续北上，形成深厚水汽耦合结构；边界水汽收支呈强辐合特征，为暴雪发展提供充足水汽。11月8日过程降雪量为8.4 cm，以近源内陆水汽补给为主，高低层输送距离较短，海洋暖湿水汽贡献不足，水汽辐合及收支强度均明显减弱。对比发现，水汽来源范围、输送路径及收支强度差异是造成两次降雪强度差异的主要原因。

Abstract: This article is based on hourly observation data from two snowfall events in Fuyu City, Jilin Province, on November 6 and 8, 2023, as well as ERA5 and GDAS reanalysis data. Using the HYSPLIT backward trajectory model and moisture budget diagnostic methods, it explores the moisture transport characteristics and differences in dynamic–moisture configurations between the two snowfall events. The results show that the heavy snow on November 6 accumulated 16.6 cm, influenced by both high-latitude cold and wet air and warm, moist air from the ocean. At the 500 hPa level, northwestern cold and wet transport was obvious, while at 700 hPa, warm and moist flow from the Sea of Japan continued advancing north, forming a deep moisture-coupled structure. The boundary layer moisture budget showed strong convergence, providing ample moisture for the snowstorm. The November 8 event accumulated 8.4 cm of snow and was mainly supported by nearby inland moisture, with shorter-distance transport in both high and low levels. Oceanic warm and moist air contributed less, and both moisture convergence and budget intensity were significantly weaker. Comparisons reveal that differences in the range of moisture sources, transport paths, and budget intensity were the main reasons for the difference in snowfall intensity between the two events.