基于EAR5数据的宁夏固原市偏南大风的特征分析

Characteristics of Strong Southerly Winds in Guyuan City, Ningxia: An Analysis Based on EAR5 Data

摘要: 基于1994~2023年逐日地面极大风速观测数据，筛选9个代表性偏南大风案例，利用ERA5再分析数据的逐小时气象要素资料，对大风天气形势分类并分析相关气象要素特征。结果表明：天气形势分三类，分别是平直西风气流下的东高西低型、宽广槽区下的东高西低型以及两槽一脊下的短波槽型；700 hPa受南风控制且常伴南风急流，地面普遍受热低压影响，大风多出现于中高空槽前暖平流区和地面热低压区。此外，700 hPa散度与地面风速显著正相关，700 hPa位势高度与多个气象要素显著相关。

Abstract: Based on daily surface maximum wind speed observations from 1994 to 2023, this study screened 9 representative cases of southern-blowing winds. Using hourly meteorological element data from ERA5 reanalysis, we classified wind patterns and analyzed their meteorological characteristics. Results indicate three main types: 1) East-high west-low configuration under steady westerly airflow, 2) East-high west-low configuration under a broad trough region, and 3) Short-wave trough pattern under two troughs and one ridge. The 700 hPa level is predominantly controlled by southerly winds and often accompanied by southerly jet streams, with surface areas generally influenced by warm low-pressure systems. Strong winds typically occur in warm advection zones ahead of meso-altitude troughs and surface thermal low-pressure areas. Additionally, 700 hPa divergence shows significant positive correlation with surface wind speed, while 700 hPa potential height demonstrates significant correlations with multiple meteorological elements.