黄河中游一次区域性暴雨过程的诊断分析和数值模拟

2021-12-17 00:46:36张利娜韩作强刘静龙晓彤
人民黄河 2021年12期

张利娜 韩作强 刘静 龙晓彤

摘 要:利用常规气象观测资料、水文观测资料和NCEP再分析资料,对2018年7月10日发生在黄河中游的一次区域性暴雨过程进行诊断分析和数值模拟。结果表明:此次强降雨是西风槽携带冷空气和副热带高压边缘暖湿气流在暴雨区上空交汇过程中发生的,低空低涡切变、低空急流和地面冷锋是主要影响系统。有利的水汽、动力和热力条件是强降雨产生、发展的物理基础。通过对各微物理过程和积云对流参数化方案组合进行对比分析发现,WRF模式能模拟出造成本次降雨的环流形势、降雨落区及雨区走向,Kessler云微物理方案和GD积云对流参数化方案在本次降雨过程的模拟中效果最佳。

关键词:暴雨;WRF模式;诊断分析;参数化方案;黄河中游

中图分类号:P458.3;TV882.1

文献标志码:A

doi:10.3969/j.issn.1000-1379.2021.12.005

引用格式:张利娜,韩作强,刘静,等.黄河中游一次区域性暴雨过程的诊断分析和数值模拟[J].人民黄河,2021,43(12):23-28,34.

Abstract: A regional rainstorm process in the middle Yellow River on July 10, 2018 was studied by the conventional meteorological data, the hydrological data and the NCEP reanalysis data. The rainstorm process was simulated by a mesoscale numerical model WRF. The results show that the intersection of westerly trough cold air and the subtropical high warm wet air in the upper level over rainstorm touches off the heavy rainfall; low-level vortex shear, low-level jet stream and the surface cold front are the main impact systems; the favorable vapor, dynamic and thermal conditions are the physical basis of precipitation occurrence and development. By comparing the different combinations of cumulus parameterizations and cloud microphysical schemes, the simulated results illustrate that the WRF model is potential in simulating and predicting this precipitation, including the circulation situation causing precipitation, rainfall area and rain belt trend. The combination of Kessler microphysical scheme and GD cumulus parameterization scheme are the best in this case.

Key words: rainstorm; WRF model; diagnostic analysis; parameterization scheme; Middle Yellow River

暴雨是常見的自然天气灾害之一,因其降雨强度大、天气系统发展快,一直是预报业务中的重点和难点。黄河中游大部分地区处于黄土高原,是黄河的主要产洪产沙区,降雨集中在夏季且多暴雨,强降雨极易产生高含沙洪水,因此对该地区强降雨进行预报分析和研究是有重要意义的。

作为新一代中尺度数值预报模式,WRF能模拟降雨的主要天气系统的位置和移动过程[1],从而使WRF模拟的降雨落区好于MM5。WRF动力框架具有一定的优越性,使其对天气形势场的模拟效果好于MM5,模拟的降雨落区和强度更接近实况[2]。……

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