青藏高原东缘边坡地区暖季降水的精细化特征分析  

Fine-scale characteristics of warm season precipitation over the eastern periphery of the Tibetan Plateau

作　　者：王钦 曾波[2] 董元昌[2] WANG Qin;ZENG Bo;DONG Yuanchang(Civil Aviation Flight University of China,Sichuan Guanghan 618307,China;Chengdu Institute of Plateau Meteorological,China Meteorology Administration/Heavy Rain and Drought-Flood Disasters in Plateau and Basin Key Laboratory of Sichuan Province,Chengdu 610072,China)

机构地区：[1]中国民用航空飞行学院广汉分院,四川广汉618307 [2]中国气象局成都高原气象研究所/高原与盆地暴雨旱涝灾害四川省重点实验室,成都610072

出　　处：《气象科学》2025年第1期57-67,共11页Journal of the Meteorological Sciences

基　　金：西藏科技厅重大专项(XZ202402ZD0006);国家自然科学基金重点资助项目(42030611);国家自然基金重大研究计划集成项目(91937301);中国气象局决策气象服务专项重点项目(JCZX2023010);高原与盆地暴雨旱涝灾害四川省重点实验室发展基金项目(SCQXKJQN202217,SCQXKJQN202216,SCQXKJYJXZD202202);川西南(雅安)暴雨实验室研究型业务面上专项(CXNBYSYSM202406)。

摘　　要：利用2013—2019年四川省信息中心提供的逐小时降水自动观测数据,分析了四川盆地西南缘与青藏高原东缘之间从平原到高原地形陡升区的降水时空分布特征。结果表明:(1)暖季降水量总体呈两高(西南部、东部)一低(中部)分布,累计降水大值中心主要位于雅安市荥经县龙苍沟。降水量与降水频率以及降水强度三者的空间配置差异性较大,其中降水强度与海拔高度呈显著负相关,即海拔越高的地区,降水强度越弱;(2)暖季小时降水的月变化和日变化均呈单峰型结构。除西北部的泸定县降水强度在6月达到峰值外,大部分地区累计降水量、降水强度均在7、8月达到峰值;(3)夜雨特征明显,日降水峰值主要出现在15—16时(世界时,下同),谷值出现在05—06时。夜雨量占全天的76%,明显多于昼雨量。累计降水量、降水频次以及降水强度的日变化峰值在水平空间上表现出自南向北、自西向东增加的趋势,时间上表现出自南向北、自东向西传播的特征,且日降水峰值出现时间随海拔增加而逐渐提前;(4)研究区域内暖季降水以0.1~1.0 mm的小时降水量为主,频率高达60%~70%。20 mm以下不同量级的降水日变化呈单峰结构,20 mm以上的短时强降水表现出双峰日变化特征,第二峰值出现在20时。随着小时降水量级的增加,对应的降水频次日变化幅度也逐渐增加,峰值时间逐渐提前。Based on the hourly rain gauge records from 2013 to 2019,the temporal and spatial distribution characteristics of warm season precipitation in the slope area between the eastern periphery of the Tibet Plateau and southwestern Sichuan basin were examined.Results show that:(1)the accumulated warm season precipitation displayed large value in both southwestern and eastern region,but low in middle,and its center located at Longcanggou,Yingjing County,Ya an City.The spatial distribution of precipitation frequency and precipitation intensity are also found quit different from that in accumulate precipitation,and among these three features,the precipitation intensity has a significant negative correlation with terrain height,that is,the higher the terrain height,the weaker the precipitation intensity.(2)The monthly and daily variations of hourly precipitation in warm season show a single peak structure.Except that,the precipitation intensity in Luding County peaks in June,but the cumulative precipitation and precipitation intensity in most study areas reach the peak in July or August.(3)The nocturnal rainfall dominates the warm season precipitation over the the eastern periphery of the Tibet Plateau.The diurnal rainfall peaks from 1500 UTC to 1600 UTC,when the lowest value reaches from 0500 UTC to 0600 UTC.The rainfall at night accounts for 76%of the whole day,which is significantly higher than that in the daytime.The diurnal peak value of cumulative precipitation,precipitation frequency and precipitation intensity show the trend of increasing from south to north and from west to East in horizontal space,and propagating from south to north and from east to west,and besides,the diurnal peaks advanced as the terrain height increased.(4)The hourly precipitation of 0.1-1.0 mm dominates the warm season precipitation in the slope area,with a high frequency of 60%-70%.The precipitation of different magnitude below 20 mm shows a single peak structure,while the short-term heavy precipitation(hourly precipitation above 20 mm)exhi

关 键 词：青藏高原边坡地区 降水量 降水频次 特征 

分 类 号：P426.6[天文地球—大气科学及气象学]