| 摘要: |
| 研究了闪电资料同化对2021年7月20日河南郑州特大暴雨短临预报的影响。利用天气研究与预报（WRF）模式的三维变分（3DVAR）数据同化系统（WRFDA），开展了两组循环同化试验：（1）同化地面和探空常规观测资料（包括风速、风向、温度和气压）的试验（CONV）；（2）同化常规观测资料和由闪电资料反演的伪相对湿度的试验（LGDA），并与无资料同化的试验（NoDA）进行对比。结果表明，CONV的分析场和NoDA都未能模拟出强对流系统的回波结构，但由于LGDA增加了对整层大气的湿度场的调整，其分析场在闪电发生位置处的水凝物增量较大，相对湿度和反射率的分布情况与中国全球大气再分析资料（CRA）及雷达反射率观测值最接近。降水预报方面，LGDA显著提高了大暴雨雨带（6 h累积降水量≥50 mm）和强降水中心（6 h累积降水量≥200 mm）位置和强度的预报效果，对本次强降水过程的预报起到了积极作用，尤其是对前3 h的降水预报。 |
| 关键词: 闪电资料同化 河南特大暴雨 三维变分同化 |
| DOI：10.16032/j.issn.1004-4965.2024.014 |
| 分类号: |
| 基金项目: |
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| Impact of Lightning Data Assimilation on Forecasting the “7.20” Extreme Heavy Rainfall in Zhengzhou, Henan Province |
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PANG Ying1, HU Junjun2,3, CHEN Sheng4, LU Gaopeng5, WU Chong6, WEI Chunxia7, HUANG Chaoying8
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1. Zhuhai-Macao Collaborative Research Center for Meteorological Innovation and Application, Zhuhai, Guangdong 519000, China;2. Key Laboratory of Land Surface Process and Climate Change in Cold and Arid Regions, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou 730000, China;3. Nagqu Station of Plateau Climate and Environment, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Nagqu, Xizang 852000, China;4. Key Laboratory of Remote Sensing of Gansu Province, Heihe Remote Sensing Experimental Research Station, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou 730000, China;5. School of Earth and Space Science, University of Science and Technology of China, Hefei 230026, China;6.6. Chinese Academy of Meteorological Sciences, Beijing 100081, China;7.7. Guangxi Zhuang Autonomous Region Institute of Meteorological Sciences, Nanning 530022, China;8.8. Dongguan Meteorological Bureau of Guangdong Province, Dongguan, Guangdong 523086, China)
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| Abstract: |
| This study evaluates the impact of lightning data assimilation (DA) on short-term forecasts of an extremely heavy rainfall event that occurred in Zhengzhou, Henan Province on July 20, 2021. Based on the Weather Research and Forecast (WRF) three-dimensional variational (3DVAR) data assimilation system (WRFDA), two cycling DA experiments were designed: one test (CONV) assimilated ground and sounding observation data (i.e., wind speed, wind direction, temperature, and air pressure), and the other test (LGDA) assimilated both conventional observations and pseudo-relative humidity observations derived from lightning data. The results of assimilated test were compared with those of the test without data assimilation (NoDA). Neither the analysis fields of CONV nor NoDA were able to simulate the echo structure of a strong convective system. Since LGDA increased the adjustment of the humidity field, its analysis field had a large increase in hydrometeor at the location where lightning strikes and the distribution of relative humidity and reflectivity was closest to the China Global Atmosphere Reanalysis data and radar reflectivity observations. The predictive precipitation shows that the spatial coverage of the rainstorm belt (6-h accumulated precipitation≥50 mm), as well as the location and amount of heavy precipitation center (6-h accumulated precipitation≥200 mm), have been well predicted by LGDA, demonstrating the positive impact of lightning DA on this extremely heavy rainfall event, especially the precipitation forecast for the first three hours. |
| Key words: lightning data assimilation extremely heavy rainfall in Henan three-dimensional variational assimilation |
