塔克拉玛干沙漠腹地夏季夜间低空急流变化特征  

Variation characteristics of nocturnal low-level jet in summer over the hinterland of Taklimakan Desert

作　　者：张建涛[1] 王敏仲[1] 何清 潘红林 孟露 王延慧 Zhang Jiantao;Wang Minzhong;He Qing;Pan Honglin;Meng Lu;Wang Yanhui(Taklimakan Desert Meteorology Field Experiment Station of CMA,Institute of Desert Meteorology,China Meteorological Administration,Urumqi 830002,China;Xinjiang Meteorological Bureau,Urumqi 830002,China;Meteorological Disaster Prevention Technology Center of Xinjiang Uygur Autonomous Region,Urumqi 830002,China)

机构地区：[1]中国气象局乌鲁木齐沙漠气象研究所塔克拉玛干沙漠气象野外科学试验基地,新疆乌鲁木齐830002 [2]新疆气象局,新疆乌鲁木齐830002 [3]新疆维吾尔自治区气象灾害防御技术中心,新疆乌鲁木齐830002

出　　处：《中国沙漠》2020年第5期89-100,共12页Journal of Desert Research

基　　金：国家自然科学基金项目(41775030);国家自然科学基金重点项目(41830968);中国沙漠气象科学研究基金项目(Sqj2019001);新疆天山青年计划项目(2017Q042)。

摘　　要：利用2016年7月和2017年7月塔克拉玛干沙漠腹地GPS探空观测试验数据,分析了夏季夜间低空急流的变化特征及成因。结果表明:塔克拉玛干沙漠腹地夏季夜间低空急流发生概率较高,较弱的低空急流(LLJ1)发生概率约为71.0%,平均急流风速为13.2 m·s-1,平均急流高度为424 m,急流风向以偏东风为主,急流风速主要分布在9~14 m·s-1,急流高度主要分布在低空200~500 m,较强的低空急流(LLJ4)分布在较高的高度上。晴天夜间低空急流形成和发展具有清晰的日变化特征,日落后开始发展,午夜达到最大,之后逐渐减弱,并在日出前后消散,急流风向随时间推移,由东北风逐渐向右偏转为偏东风或东南风。沙尘暴天气对低空急流的发展具有促进作用,急流风速可在沙尘暴风速的基础上进一步增大,形成较强的夜间低空急流。天气系统的强迫对沙漠腹地夜间低空急流强度影响较大,但时间较短,而惯性震荡和地形因素对急流强度影响较弱,但能够长期影响低空急流的形成和发展。In this paper,based on the data of GPS sounding observation in July of 2016 and 2017 in the hinterland of the Taklimakan Desert,the variation characteristics and causes of nocturnal low-level jet(NLLJ)in summer are analyzed. The results show that the occurrence probability of NLLJ is high in the Taklimakan Desert hinterland in summer. The probability of weak NLLJ is about 71. 0%,the average jet velocity is 13. 2 m·s-1,the average jet height is 424 m,the main wind direction of the jet is easterly,the jet velocity is mainly distributed in the range of 9-14 m·s-1,the jet height is mainly distributed in the low level of 200-500 m,and the strong NLLJ is distributed in the higher altitude. In addition,the formation and development of NLLJ on a clear day presents a clear diurnal variation. It starts to develop after sunset,reaches its maximum at midnight,then gradually weakens,and dissipates before and after sunrise. The jet wind direction gradually deflects from northeast wind to east wind or southeast wind with the passage of time. Furthermore,sandstorm can promote the development of NLLJ,and the speed of jet can be further increased on the basis of sandstorm,forming a strong NLLJ. The forcing of weather system has a great influence on the intensity of NLLJ in the hinterland of the Taklimakan Desert,but the time is short. The inertial concussion and terrain factors attach a weak influence on the intensity of jets,but they can affect the formation and development of NLLJ for a long time.

关 键 词：夜间低空急流 塔克拉玛干沙漠 惯性震荡 日变化 

分 类 号：P425[天文地球—大气科学及气象学]