不同水汽源地对夏季青藏高原降水过程影响的模拟研究  

Influence of Different Water Vapor Sources on the Precipitation Processes on the Qinghai-Xizang(Tibet)Plateau in Summer

作　　者：朱昌睿 宋敏红 张少波 马龙腾飞 ZHU Changrui;SONG Minhong;ZHANG Shaobo;MA Longtengfei(Chengdu University of Information Technology/Sichuan Key Laboratory of Plateau Atmosphere and Environment,Chengdu 610225,Sichuan,China)

机构地区：[1]成都信息工程大学大气科学学院/高原大气与环境四川省重点实验室,四川成都610225

出　　处：《高原气象》2023年第5期1129-1143,共15页Plateau Meteorology

基　　金：第二次青藏高原综合科学考察研究项目(2019QZKK0103)。

摘　　要：基于对青藏高原夏季水汽来源主要为阿拉伯海、孟加拉湾和南海三地的认知,开展了不同水汽源地对青藏高原夏季东部型和西部型降水影响的模拟研究。利用常规观测资料、NCEP/NCAR全球再分析资料以及中尺度数值模式WRF对2016年6月28日至7月2日(东部型)和2018年7月19-23日(西部型)青藏高原上两次强降水过程进行了不同水汽源地水汽含量减少的数值模拟试验,通过将阿拉伯海、孟加拉湾和南海三地的相对湿度分别由地面至100 hPa依次减少70%、60%、50%、40%、30%三组敏感性试验和控制性试验的对比,从环流场、水汽输送及降水变化等角度深入探讨不同水汽源地水汽含量的减少对高原夏季降水的影响,得到以下主要结论:(1)三个水汽源地水汽含量的减少对青藏高原夏季降水有影响且影响程度不同,其中减少孟加拉湾上空水汽,使2016年(东部型)和2018年(西部型)青藏高原夏季降水量相较于控制性试验显著下降约10%,而减少南海上空水汽对两次高原夏季降水过程影响极小。减少阿拉伯海上空水汽对高原西部型降水起促进作用,降水量相对于控制性试验增加约10%;对高原东部型降水抑制作用,使得降水量相较于控制性试验减少约5%。(2)改变孟加拉湾水汽源地的水汽条件对高原降水影响最明显,可能的原因是减少孟加拉湾上空水汽条件,使得高原南侧的低值系统有所减弱,高原上偏南风减弱,水汽输送较弱,致使高原上的降水减少。(3)在模拟初期控制性试验和三个敏感性试验的高原地区水汽收支差异不明显,但随着模拟时间的增加(约48 h后),青藏高原地区水汽收支存在明显差异,且水汽收支情况与日降水量存在明显的相关关系。Based on the knowledge that the main sources of summer water vapor on the Qinghai-Xizang(Tibet) Plateau are the Arabian Sea,the Bay of Bengal,and the South China Sea,a simulation study of the effects of different water vapor sources on the eastern-type and western-type precipitation on the Qinghai-Xizang(Tibet) Plateau in summer was carried out.Numerical simulations of water vapor content reduction at different water vapor source locations were conducted using conventional observations,NCEP/NCAR global reanalysis data,and the mesoscale numerical model WRF for two intense precipitation processes on the Qinghai-Xizang(Tibet) Plateau from June 28 to July 2,2016(eastern type) and from July 19 to 23,2018(western type),by separately integrating the Arabian Sea,Bay of Bengal,and South China Sea By comparing three sets of sensitivity experiment and control experiment,the relative humidity at the Arabian Sea,the Bay of Bengal and the South China Sea was reduced by 70%,60%,50%,40% and 30% from the ground to 100hPa respectively,and the effects of the reduction of water vapor content at different water vapor sources on summer precipitation on the plateau were explored in depth from the perspectives of circulation field,water vapor transport and precipitation changes,and the following main conclusions were obtained:(1) The reduction of water vapor content at three water vapor sources has an effect on The reduction of water vapor over the Bay of Bengal significantly reduced the summer precipitation of the Qinghai-Xizang(Tibet) Plateau by about 10% in 2016(eastern type) and 2018(western type) compared with the controlled experiment,while the reduction of water vapor over the South China Sea had minimal effects on the two summer precipitation processes of the Qinghai-Xizang(Tibet) Plateau.Reducing the water vapor over the Arabian Sea plays a catalytic role in the precipitation of the western type of the plateau,increasing the precipitation by about 10% relative to the controlled test;and inhibiting the precipitation of the easte

关 键 词：青藏高原 敏感性试验 水汽源地 水汽通量 

分 类 号：P426[天文地球—大气科学及气象学]