{"title":"Aircraft observations of tropical cyclones core structure over the South China Sea and their impacts on track and intensity forecasts","authors":"Chengzhong Zhang , Pak-wai Chan , Sheng Hu , Yerong Feng , Shuixin Zhong , Yanyan Huang","doi":"10.1016/j.dynatmoce.2025.101580","DOIUrl":null,"url":null,"abstract":"<div><div>In this study, characteristics of wind and temperature in the inner-core region of tropical cyclones (TCs) are analyzed using dropsonde data from three aircraft observation missions over the South China Sea (SCS) conducted by the Hong Kong Observatory between 2022 and 2023. The impact of assimilating inner-core dropsonde data on TC track and intensity forecasts is also evaluated. Results indicate that both TCs Nesat and Suola exhibit shared features: Tangential wind speeds weaken significantly above 850–500 hPa; A distinct warm core structure persists between 700 and 300 hPa; The boundary layer height varies across cases. Two parallel experiments,ASSI_drop (with inner-core dropsonde assimilation) and No_da (without assimilation), were implemented using the GRAPES (Global/Regional Assimilation and Prediction System) model with 3DVar. Data assimilation significantly reduced 72-hour mean track errors (49 % of reduction), while intensity forecasts showed neutral to weak positive improvements. The track improvement closely aligns with Feng et al. (2023)'s reduction via inner-core assimilation in northern SCS cases, while substantially exceeding the 10–13 % range documented in analogous SCS studies (Chan et al., 2018; Zhang et al., 2020). North Pacific DOTSTAR(Dropwindsonde Observations for Typhoon Surveillance near the Taiwan Region)cases demonstrated a 22 % mean improvement (Wu et al., 2007), contrasting with the SCS's 10–49 % variability range. This regional inconsistency underscores the necessity for expanded airborne dropsonde campaigns across the SCS to establish result representativeness and regional applicability.</div></div>","PeriodicalId":50563,"journal":{"name":"Dynamics of Atmospheres and Oceans","volume":"111 ","pages":"Article 101580"},"PeriodicalIF":1.9000,"publicationDate":"2025-07-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Dynamics of Atmospheres and Oceans","FirstCategoryId":"89","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0377026525000557","RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"GEOCHEMISTRY & GEOPHYSICS","Score":null,"Total":0}
引用次数: 0
Abstract
In this study, characteristics of wind and temperature in the inner-core region of tropical cyclones (TCs) are analyzed using dropsonde data from three aircraft observation missions over the South China Sea (SCS) conducted by the Hong Kong Observatory between 2022 and 2023. The impact of assimilating inner-core dropsonde data on TC track and intensity forecasts is also evaluated. Results indicate that both TCs Nesat and Suola exhibit shared features: Tangential wind speeds weaken significantly above 850–500 hPa; A distinct warm core structure persists between 700 and 300 hPa; The boundary layer height varies across cases. Two parallel experiments,ASSI_drop (with inner-core dropsonde assimilation) and No_da (without assimilation), were implemented using the GRAPES (Global/Regional Assimilation and Prediction System) model with 3DVar. Data assimilation significantly reduced 72-hour mean track errors (49 % of reduction), while intensity forecasts showed neutral to weak positive improvements. The track improvement closely aligns with Feng et al. (2023)'s reduction via inner-core assimilation in northern SCS cases, while substantially exceeding the 10–13 % range documented in analogous SCS studies (Chan et al., 2018; Zhang et al., 2020). North Pacific DOTSTAR(Dropwindsonde Observations for Typhoon Surveillance near the Taiwan Region)cases demonstrated a 22 % mean improvement (Wu et al., 2007), contrasting with the SCS's 10–49 % variability range. This regional inconsistency underscores the necessity for expanded airborne dropsonde campaigns across the SCS to establish result representativeness and regional applicability.
期刊介绍:
Dynamics of Atmospheres and Oceans is an international journal for research related to the dynamical and physical processes governing atmospheres, oceans and climate.
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