辽宁暴雨的日变化特征及其成因分析  

Characteristic analysis and mechanism study of the diurnal variation of heavy rain in Liaoning

作　　者：公颖[1] 杨阳[1] 周小珊[1] 董博[2] GONG Ying;YANG Yang;ZHOU Xiaoshan;DONG Bo(Shenyang Institute of Atmosphere Environment, CMA, Shengyang 110016;Shengyang Meteorology Bureau, Shengyang 110016)

机构地区：[1]中国气象局沈阳大气环境研究所,沈阳110016 [2]沈阳市气象局,沈阳110016

出　　处：《暴雨灾害》2017年第2期125-131,共7页Torrential Rain and Disasters

基　　金：中国气象局沈阳大气环境研究所中央级公益性科研院所基本科研业务专项(2012IAE-CMA07)

摘　　要：利用长时序(1961—2012年)的辽宁省夏季逐小时降水观测资料、2008—2013年CMORPH(中国自动站与NOAA气候预报中心morphing技术融合的逐时降水量0.1°网格数据)夏季逐小时降水资料、2000—2012年NCEP再分析资料以及高分辨率中小尺度数值模式WRFV3.3.1,对辽宁暴雨日变化规律进行了统计,并对其形成机理进行了分析和数值试验,结果表明:(1)辽宁省内陆地区基本为午后降水(暴雨)峰值,沿海地区基本为午前降水(暴雨)峰值,内陆平原站点凌晨到午前有次峰现象发生。(2)辽宁降水日变化特征与地理环境关系密切,内陆地区午后降水峰值、沿海地区午前降水峰值的主要原因是大兴安岭—内蒙古高原山区、东北平原、海洋三大地形热力性质的不同而诱发的局地环流日变化。内陆地区午后—夜间降水峰值由山地—平原局地环流上升支诱发,沿海地区凌晨—午前降水峰值现象由海—陆局地环流上升支诱发。(3)对内陆站点做去除大地形试验的数值模拟试验表明,去除大地形对于日累积降水量无明显影响,但对内陆站点的降水日变化有影响,去掉地形后,内陆站点降水峰值发生时间基本均明显提前至正午前后且峰值雨量均明显减小;沿海站点做海洋改陆地数值模拟试验结果表明,海洋改陆地试验对于日累积降水量也无明显影响,但对沿海站点降水日变化有影响,海洋改为陆地后,沿海站点降水峰值由午前变为午后至夜间。数值试验结果进一步说明山地、海洋大地形是诱发辽宁降水日变化规律形成的主要原因。Using long time series(1961-2012)observational hourly rainfall data in Liaoning province,hourly0.1°×0.1°resolution mergedprecipitation products over whole China from2008to2013,NCEP reanalysis data from2000to2012and high resolution meso-scale numericalmodel WRFV3.3.1,the characteristcs of the diurnal variation of heavy rain in Liaoning province were summarized,and the mechanismshave been analyzed and numerically examined.The results are as follows.(1)The(heavy)rain peak inland of Liaoning province mostly happensfrom afternoon to midnight,while that inshore mostly happens in the morning.There is a secondary peak for inland plain stations from weehours to morning.(2)There is a close relationship between the behavor of precipitation diurnal variation and the geographical environment inLiaoning province.The main reason of the rain peak in the afternoon inland and in the forenoon inshore is the local circulation diurnal variationcaused by difference of thermodynamic character among the mountainous area,Northeast plain and the ocean.The rain peak inland from afternoonto midnight is caused by the updraft of the mountain-plain local circulation,while the inshore rain peak from wee hours to forenoon iscaused by the updraft of the ocean-land local circulation.(3)The numerical test for inland stations without mountains shows that the daily accumulatedrainfall was not affected,but the precipitation diurnal variation was obviously affected.After removing the mountains,the rain peakwas advanced to noon and the peak value became smaller.The numerical test for inshore stations when altering ocean to land shows that thedaily accumulated rainfall was also not affected,and the precipitation diurnal variation was again obviously affected.After altering ocean toland,the rain peak of inshore stations occurred at night instead of in the morning.In summary,the result of numerical test further illustratesthat the large terrain of mountain and ocean is the main factors causing the precipitation diurnal variation in Liaoning province.

关 键 词：暴雨日变化 降水峰值 地理环境 

分 类 号：P463.213[天文地球—大气科学及气象学]