Applicability assessment of CRA40 reanalysis data in the study of the extreme heavy precipitation occurred in July,2021
Based on actual observed data,a comparative analysis was conducted to assess the performance of ERA5,CRA40,CFSR,and NCEP/NCAR reanalysis datasets in the study of the extreme rainstorm occurred in July 2021.ERA5 data was used as the reference for comparison,and the applicability of CRA40 data was evaluated in the study of extreme rainstorms.Results show that:(1)the intensity estimation on Typhoon"In-Fa",the subtropical high,and other key circulation systems by the four datasets is consistently lower.CRA40's analysis of the geopotential height field aligns well with ERA5,and the circulation pattern is closer to the actual conditions.The intensity estimation of the 200 hPa upper-level jet stream is the highest in ERA5,and the difference between CRA40 and ERA5 is minimal.In terms of reproducing the lower-layer wind speed in the troposphere,CRA40 is equivalent to ERA5.None of the four datasets can reproduce the strengthening and turning point of Typhoon"In-Fa".(2)In the 925 hPa temperature field,compared with other datasets,the ERA5 temperature is lower in the Qinghai-Tibet Plateau region,and the CRA40 temperature is the highest.For the process of weak cold air intruding into the northern part of Henan Province,CRA40 and ERA5 results are the closest.CRA40's depiction of water vapor flux and its divergence is relatively close to ERA5 in terms of distribution and numerical values.(3)Both CRA40 and ERA5 datasets depict favorable dynamic conditions in the upper atmosphere over Zhengzhou station in July 2021.In terms of intensity,CRA40 is slightly weaker than ERA5,and the two datasets show consistent features in terms of meridional/zonal circulation and vorticity.
CRA40ERA5rainstorm in July 2021reanalysis datadata assessment
万方数据
