摘要
2022年6月6~10日我国江淮-华南地区发生一次大范围强降水过程,造成重大洪涝灾害。强降水发生在850 hPa切变线附近,当切变线南压至华南地区时,配合西南暖湿气流,造成华南地区大暴雨降水。利用ERA5再分析数据及降水融合产品,评估了中国气象局全球同化预报系统(CMA-GFS)对此次过程的预报效果,诊断了预报偏差来源,进行了针对性敏感试验。结果表明:CMA-GFS对影响此次雨带位置和移动的南亚高压脊线移动、副高范围变化趋势以及850 hPa切变线移动预报与再分析结果一致,因此对雨带位置和移动趋势预报效果较好,但存在切变线降水偏弱,福建东部沿海、广东北部及广西中部的分散性大暴雨漏报,广东北部雨带偏北及暖区暴雨漏报问题;偏差诊断显示,CMA-GFS对切变线北侧风速预报偏弱3~8 m/s,广西、广东中北部水汽辐合偏弱2×10^(-5)~5×10^(-5)g/(m^(2)·Pa·s),导致切变线降水偏弱,南侧南风分量偏强3~5 m/s导致广东北部雨带偏北约60 km,华南沿海850 hPa急流偏弱4~6 m/s,暖区水汽输送偏少4~10 g/(cm·hPa·s),导致暖区暴雨漏报;采用美国全球预报系统(NCEP-GFS)分析场初始化明显改善了雨带位置预报,采用WSM6云微物理方案及收紧积云对流参数化方案中对流触发条件改善了切变线降水中心位置和量级预报,暖区降水量级也由小到中雨增强至中到大雨。
A large-scale heavy precipitation occurred in Jianghuai-South China from June 6 to 10,2022,causing severe floods and waterlogs.The precipitation mainly appeared near the shear line at 850 hPa.When the shear line moved to South China and coincided with the southwest warm and humid air,it resulted in a rainstorm in the region.In this paper,the performance of the China Meteorological Administration Global Forecast System(CMA-GFS)on this process is evaluated using ERA5 reanalysis and merging precipitation products.The diagnosis of forecast deviations and sensitivity experiments are also conducted.The results show that the movement of the South Asia high ridge,range of subtropical high,and the movement of the shear line at 850 hPa forecast by CMA-GFS that affect the location and shift of the rain belt are consistent with the results of ERA5 reanalysis.Therefore,the CMA-GFS performed well on the location and shift of this rain belt.However,the forecast has some deficiencies including that the precipitation along the shear line is weak,scattered heavy rainstorms in eastern Fujian,Northern Guangdong and central Guangxi are missed,the rain belt in northern Guangdong is located northward,and the magnitude of precipitation in warm sector is under estimated.The deviation diagnosis reflects that the wind speed forecast on the north side of the shear line is weaker by 3~8 m/s,and the water vapor convergence over the central and northern parts of Guangxi and Guangdong is weaker by 2×10^(-5)~5×10^(-5)g/(m^(2)·Pa·s),resulting in the weak precipitation on the shear line.The wind forecast on the south side is stronger by 3~5 m/s,resulting in the rain belt in northern Guangdong located northward by approximately 60 km.The jet over the South China coast at 850 hPa is weaker by 4~6 m/s,and the water vapor fluxes in the warm area are less by 4~10 g/(cm·hPa·s),resulting in the less rainstorms in the warm sector.Some numerical experiments are carried out to modify these deviations forecast by CMA-GFS.Using the analysis of the Natio
作者
王蕾
陈起英
徐国强
胡江林
WANG Lei;CHEN Qiying;XU Guoqiang;HU Jianglin(CMA Earth System Modeling and Prediction Centre/Key Laboratory of Earth System Modeling and Prediction,China Meteorological Administration,Beijing 100081,China)
出处
《中山大学学报（自然科学版）（中英文）》
CAS
CSCD
北大核心
2024年第2期46-58,共13页
Acta Scientiarum Naturalium Universitatis Sunyatseni
基金
中国气象局能力提升联合研究专项(22NLTSZ006)
风云卫星应用先行计划。
关键词
CMA-GFS
强降水
误差诊断
预报改进
CMA-GFS
heavy precipitation
deviation diagnosis
model improvement
