Comparative Analysis of Sounding Rocket Data and ERA5 Reanalysis Data Under Typhoon Conditions

ZHENG Yi; ZHAO Bingke; CHEN Yonghang; LIU Qiong; LIU Tongqiang; SONG Jinke; WEI Xin; WEI Yu; LUO Weiting

doi:10.16032/j.issn.1004-4965.2024.047

Abstract：The accuracy of reanalysis data is crucial for numerical model predictions and stratospheric studies.However,there is a lack of direct observational data in the stratosphere during strong typhoon conditions.This study compares meteorological parameters under strong typhoon conditions using ERA5 reanalysis data and a new type of sounding rocket data.The findings are as follows:(1)Temperature profiles in the troposphere for the three typhoon experiments are nearly identical between ERA5 and sounding rocket data.The mean error between the two datasets is less than 1℃ below 15 km.However,as altitude increases in the stratosphere,the deviation between ERA5 and sounding rocket data becomes more significant.ERA5 consistently shows lower temperatures compared to the sounding rocket data.The mean deviations between ERA5 and rocket data are 3.75℃,5.52℃,14.41℃,and 19.25℃ in the altitude ranges of 15～20 km,20～30 km,30～40 km,and above 40 km,respectively.(2)Regarding relative humidity,both datasets exhibit similar trends.However,there is a notable difference in the lower stratosphere(15～20 km).According to the sounding rocket data,the boundary altitude for dry and humid air is around 15 km,while ERA5 suggests this boundary is above 20 km.It is worth mentioning that both datasets show that relative humidity above 25 km is close to 0% before the typhoon's impact.During the typhoon's impact,the sounding rocket data indicates relative humidity can reach up to 5%,whereas ERA5 still shows relative humidity close to 0% .(3)Wind speed profiles during the three typhoon experiments demonstrate high similarity and correlation coefficients of approximately 0.85 in the troposphere and lower stratosphere.The average deviation is around 2 m·s-1.However,as altitude increases in the middle and upper stratosphere,the similarity decreases,and the deviation increases.ERA5 consistently shows wind speeds approximately 4 m·s-1 lower than the sounding rocket data.