2014年南疆西部一次大风天气过程分析  

An Analysis on a Strong Windy Weather Process Over the West of South Xinjiang in 2014

作　　者：周宏 杨利鸿 胡素琴 宋利生 那斯尔江.帕塔尔 卓亚克孜.赛帕吉 冉金玉 

机构地区：[1]岳普湖县气象局,喀什岳普湖844400 [2]喀什地区气象局,新疆喀什844000 [3]贡山县气象局,云南贡山673500 [4]塔什库尔干县气象局,新疆喀什845250 [5]吐尔尕特气象站,新疆喀什844000

出　　处：《沙漠与绿洲气象》2015年第6期50-55,共6页Desert and Oasis Meteorology

基　　金：公益性行业专项(GYHY201306066)资助

摘　　要：利用常规地面、高空观测资料和NECP逐日4次1毅伊1毅网格再分析资料,对2014年5月22日发生在南疆西部地区的一次翻山型大风天气过程的物理机制进行了诊断分析。结果表明：此次大风是高压脊衰退,冷空气沿西北路径爆发产生的大风天气过程;喀什站与乌鲁木齐、塔什干指标站气压差有明显的指示意义：喀什站与乌鲁木齐站气压差由负转正达到＋3 h Pa左右,与塔什干站气压差达到最大-26 h Pa左右,此时可作为出现全区性大风的参考时间节点,当喀什站与乌鲁木齐站气压差扩大到-15 h Pa左右并维持稳定,与塔什干气压差减小至-13 h Pa左右,可作为全区性大风结束的参考时间节点;同时大风出现及结束时间节点在地理上呈现阶梯性变化特征;高空急流、垂直速度圈、变压中心以及冷锋的位置变化相互制约影响;中低层300~850 h Pa较深厚的强冷平流输送,盆地热低压发展是翻山大风形成的热力因子。The physical mechanism of the gale weather process across mountain in Kashgar on May22 in 2014 was diagnosed and analyzed using conventional surface observation and NEPC reanalysisdata. The results indicated that the gale was caused by ridge decline and cold air outburst along thenorthwest path. Pressue differences of Kashgar, Urumqi and Tashkent stations had indicativesignificance： pressure differences between Kashgar and Urumqi changed from negative to positive,reaching around ＋3 h Pa. Meanwhile pressure differences between Kashgar and Tashkent reachedthe maximum, about-26 h Pa, and this could be the reference of time node when the district galeoccurred. When pressure differences between Kashgar and Urumqi raised to about-15 h Pa andpressure differences between Kashgar and Tashkent reduced to around-13 h Pa, remaining stable,this could be the reference time node when the district gale ended. Upper-level jet-stream, verticalvelocity, variable pressure center and the variation of space position in cold front interacted witheach other. The interaction of upper jet-stream and vertical circulation were the vital dynamicmechanism of downward momentum transferring from upper air. Convergence in the low layer ofsouth Xinjiang Basin and divergence in Pamirs exacerbated the rising decompression in southXinjiang basin and sinking compression in low-middle layer of Pamirs, which was another dynamicmechanism. The transportation of deep and strong cold advection between 300 h Pa and 850 h Pa,and development of thermal low were the thermodynamical factor for the strong wind acrossmountain.

关 键 词：南疆西部 翻山型大风 高压脊衰退 西北路径 物理机制 

分 类 号：P458[天文地球—大气科学及气象学]