| “21·7”河南极端强降水特征及环流异常性分析 |
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| 引用本文： | 张霞,杨慧,王新敏,申琳,王迪,栗晗.“21·7”河南极端强降水特征及环流异常性分析[J].大气科学学报,2021,44(5):672-687. |
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| 作者姓名： | 张霞 杨慧 王新敏 申琳 王迪 栗晗 |
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| 作者单位： | 中国气象局 河南省农业气象保障与应用技术重点开放实验室, 河南 郑州 450003;河南省气象台, 河南 郑州 450003;长江生态环保集团有限公司, 湖北 武汉 430062 |
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| 基金项目： | 中国气象局河南省农业气象保障与应用技术重点实验室重点项目（KZ202001）；河南省2021年度国家超级计算郑州中心创新生态系统建设科技专项（201400210800） |
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| 摘 要： | 基于国家自动站及区域自动站降水观测资料、欧洲中心大气再分析资料（ERA5）分析了河南“21·7”过程的降水特征及环流和物理量的异常性，并对比1981年以来郑州和鹤壁50 mm以上强降水过程的物理量特征。结果表明：1）“21·7”强降水过程在累计降水量、强降水覆盖范围、日雨量和小时雨强等方面均表现出显著极端性，过程累计降水量超过400 mm的站点集中分布在太行山东麓沿山地区和伏牛山东侧迎风坡一侧，与地形关系十分密切。2）南亚高压增强东伸，副热带高压异常偏强偏北，低纬度地区活跃的低值系统等大气环流异常，导致了水汽稳定持久向河南输送，太行山和伏牛山沿山一带水汽辐合偏离气候态最强超过-10σ，表现出显著极端性。3）“21·7”过程中，动力条件的异常特征十分显著，200 hPa的辐散中心分别位于伏牛山和太行山东麓沿山一带，相较历史气候态偏离度达到2σ～5σ；伏牛山沿山一带850 hPa涡度偏离气候态程度较太行山东麓一带更大，达6σ；而700 hPa上升运动则是太行山东麓一带极端性更强，标准差达-3σ～-5σ。4）与1981年以来同区域暴雨过程相比，“21·7”过程中，850 hPa涡度和700 hPa垂直速度的标准差为历次过程最大（最小）或次大（次小）者，对暴雨极端性有指示意义，地形附近历次暴雨过程物理量统计显示，伏牛山和太行山东麓的850 hPa辐合及700 hPa垂直速度平均偏离气候态超过3σ（-3σ），且偏离程度与日雨量呈正相关。
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| 关 键 词： | 极端强降水 环流异常 标准差 地形抬升 |
| 收稿时间： | 2021/9/7 0:00:00 |
| 修稿时间： | 2021/9/22 0:00:00 |
Analysis on characteristic and abnormality of atmospheric circulations of the July 2021 extreme precipitation in Henan |
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| ZHANG Xi,YANG Hui,WANG Xinmin,SHEN Lin,WANG Di,LI Han.Analysis on characteristic and abnormality of atmospheric circulations of the July 2021 extreme precipitation in Henan[J].大气科学学报,2021,44(5):672-687. |
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| Authors: | ZHANG Xi YANG Hui WANG Xinmin SHEN Lin WANG Di LI Han |
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| Institution: | Henan Key Laboratory of Agrometeorological Support and Applied Technique, CMA, Zhengzhou 450003, China;Henan Meteorological Observatory, Zhengzhou 450003, China;Yangtze Ecology and Environmental Co., Ltd., Wuhan 430062, China |
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| Abstract: | The severe torrential rain attacked Henan province during July 17-22 in 2021 (abbreviation "21·7") whenever the process total rainfall amount reaches 1 122.6 mm and the hourly rain intensity at Zhengzhou national observation is up to 201.9 mm/h which broke through the meteorological record of hourly rain intensity extreme value in Chinese inland since 1951.The precipitation features and abnormality of atmospheric circulations and the environmental physical quantities were analyzed with the comparative analysis of physical quantities in the process of heavy rain over 50 mm in Zhengzhou and Hebi since 1981 based on the national and regional automatic meteorological observation data and the high resolution European central atmospheric reanalysis (ERA5).As shown by the results, the "21·7" severe rainfall process presents significant extremes in terms of cumulative precipitation, heavy rainfall coverage, daily rainfall, and hourly rainfall intensity.The eastern foot of Taihang Mountain and the windward slope of eastern Funiu Mountain are the only two locations with accumulated precipitation over 400 mm, which are closely related to topography.Anomalies in atmospheric circulation such as the enhancement and eastward extension of the South Asian high, the northward anomaly of the subtropical high, and the low-value system in low-latitude regions are responsible for the stable and lasting water vapor transport to Henan province.Water vapor convergence along Taihang and Funiu Mountain was below -10σ, showing significant extremes.Dynamic conditions are also apparent in the "21·7" process.With a deviation of 2σ-5σ from the historical climate, the divergence centers are located along the eastern foothills of Taihang Mountain and Funiu Mountain in 200 hPa.The deviation of 850 hPa vorticity from the climate state along Funiu Mountain is higher than that on the eastern foot of Taihang Mountain while the deviation of 700 hPa vertical velocity from the climate is more extreme on the eastern foot.For the same region since 1981, the standard deviation of 850 hPa vorticity and 700 hPa vertical velocity is the largest (least) or the secondary maximum (minimum) in the process of "21·7", which indicates the extreme rain.In the eastern foot of Taihang Mountain and Funiu Mountain, the deviations of 850 hPa convergence and 700 hPa vertical velocity are consistently greater than 3σ(-3σ) on average, positively correlated with daily rainfall. |
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| Keywords: | extreme precipitation circulation anomaly standard deviation terrain elevation |
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