南海西沙高空风的变化特征  

Characteristics of the Variation of Upper⁃level Winds at Xisha,South China Sea

作　　者：欧阳海霞 周宇 周海霞 唐海荣 何飞淼 OUYANG Hai-xia;ZHOU Yu;ZHOU Hai-xia;TANG Hai-rong;HE Fei-miao(Sansha Meteorological Service,Sansha,Hainan 573199)

机构地区：[1]三沙市气象局,海南三沙573199

出　　处：《广东气象》2024年第3期45-49,55,共6页Guangdong Meteorology

基　　金：海南省气象局科研项目(HNQXSX202204)。

摘　　要：利用南海西沙高空气象探测站2007—2022年逐日07:00风资料,分析了规定标准等压面层、最大风层、零度层和对流层顶风向风速的变化特征,结果表明:西沙探空规定等压面层风向均呈双峰型特征,风向随季节的变化有明显的差异。最大风层风向比较集中,主要以ENE风为主,西沙夏季风旺盛时期是最大风层出现频率最高时期,两者出现时间比较一致;高空的最大风层以ENE风为主,平均高度在15 000~16 000 m之间。零度层主要风向为WSW风,在夏季风旺盛期零度层的平均气压最低,平均高度最高。南海西沙历年只在150~40 hPa之间出现第2对流层顶,对流层顶风向以ENE风为主;西沙夏季风最旺盛时期对流层顶风向最集中,以ENE风向为主,风速达到最大。Using the daily data of 07:00 winds from an upper⁃level meteorological station at Xisha,South China Sea from 2007 to 2022,this paper analyzed the characteristics of wind direction and speed vari⁃ations for mandatory isobaric surface layers,maximum wind layers,zero⁃degree layers and the tropopause.The results are shown as follows.The wind directions of Xisha as detected by radiosonde at mandatory iso⁃baric surface layers are bimodal and their variations differ much with with the season.The wind direction is relatively concentrated for the layer of maximum wind,mainly at ENE.For Xisha,summer monsoons prevail at a time when the maximum wind layer occurs most frequently,being highly consistent in the time of occur⁃rence.The maximum wind layer at the upper level is mainly of the ENE wind and at heights between 15000 and 16000 m on average.Dominated by the WSW wind,the layer with zero degree of temperature has the lowest average air pressure and highest average altitude when the summer monsoon prevails.Historically,the layer between 150 and 40 hPa is the only layer for Xisha where a secondary tropopause occurs,at which the wind direction is mainly of ENE.At Xisha,the tropopause wind direction concentrates at ENE and the wind speed is the maximum when the summer monsoon is at its prime stage.

关 键 词：气候学 标准等压面层 最大风层 零度层 对流层顶 西沙 

分 类 号：P46[天文地球—大气科学及气象学]