祁连山区大雨特征及其与副高的关系  

Characteristics of Heavy Rainfall Over Qilian Mountain and Its Relationship with Subtropical High

作　　者：邓永龙 谢启玉 

机构地区：[1]青海省海北州气象台,青海海晏810200

出　　处：《现代农业科技》2017年第2期186-188,190,共4页Modern Agricultural Science and Technology

基　　金：青海省气象局预报员专项(201526)

摘　　要：利用2010—2015年5—9月祁连山区6个国家气象站、23个区域自动站逐日降水资料以及每日2次探空资料和常规气象观测资料,统计并分析了祁连山区大雨过程(以下简称大雨)的特征及其与副高的关系。结果表明:祁连山区大雨发生在每年5—9月,6年共出现42次(90站次),连续2 d大雨有6次;2个大雨中心分别位于门源盆地和刚察地区,祁连山西部为少雨区。且大雨的年、月和旬际变化均呈现双峰型。大雨与副高西脊点、北界关系密切,大雨前3 d副高偏西,前1~2 d副高东移或分为东、西2个部分,当日副高分布在70°~105°E范围内。8月除外,其他月份大雨前3 d副高偏南,前1~2 d副高北抬,5—8月当日,副高北界在35°~45°N之间,而9月在30°~40°N之间;大雨日在关键区的副高脊线平均维持3~6 d,最长5~15 d,最短为1~3 d。大雨还与副高面积有关,大雨前2 d较之前3 d副高面积扩大,即副高西伸北抬,引导低纬的西南气流沿副高西侧向北推进,为大雨区提供充沛的水汽;前0~1 d副高东移南压,面积明显减小,致使北方南下的冷空气和沿副高西侧北上的暖湿气流得以交汇并产生强降水。Characteristics of heavy rainfall over Qilian Mountain（QM） and its relations with Subtropical High（SH）were analyzed by daily rainfall data,twice daily radiosonde data and the convention meteorological data of 6 national stations and 23 regional stations between May and September during 2010-2015. The results were as follows ：Heavy rainfall over QM appeared between May and September every year and about 42 times（90 stations）in years,continuous two-days heavy rainfall were 6 times. The centers of heavy rainfall were in Men-yuan Basin and Gangcha region,and the western region of QM was less rain. Its yearly,monthly and ten-days change all appeared two peaks. The heavy rainfall was closely related to the western ridge point and the northern border of SH,the SH was westerly 3 days before the heavy rainfall,eastward or distributed into two parts 1~2 days before the heavy rainfall,and SH appeared longitude of 70°~105°E. Except in August,the northern border of SH was southerly 3 days before the heavy rainfall,continuously northward 1~2 days before the heavy rainfall,it was mainly between 30°N and 40°N in September,and between 35°N and 45°N in other months. The ridge of the SH meanly maintained 3~6 days,the longest were 5~15 days and the shortest were 1~3 days. The heavy rainfall was also related to SH proportion. The SH proportion enlarged 3 days than 2 days before the heavy rainfall,that simultaneously northward and leading to northward of southwest airflow of lower latitude,which provided abundant water vapor for the heavy rainfall. The SH was eastward and southward and the proportion decreases 1 day before the heavy rainfall which made the cold air from the northern region southward and the warm and moist air along the border of SH northward,their merge led to heavy rainfall.

关 键 词：大雨 特征 副高 关系 祁连山区 

分 类 号：P426.62[天文地球—大气科学及气象学]