四川盆地一次强降水过程水汽特征  

Cooperative Analysis of a Heavy Precipitation Process in Sichuan Basin by Using WRF Model and Ground-Based GPS Water Vapor Data

作　　者：宋雯雯 李国平[2,3] 王皓 

机构地区：[1]高原与盆地暴雨旱涝灾害四川省重点实验室,成都610072 [2]成都信息工程大学大气科学学院,成都610225 [3]气象灾害预报预警与评估协同创新中心,南京210044 [4]成都信息工程大学大气探测学院,成都610225

出　　处：《气象科技》2018年第1期129-138,共10页Meteorological Science and Technology

基　　金：国家自然科学基金(41675057;91337215;41405036);公益性行业(气象)科研专项(GYHY201206042);中国气象科学研究院基本科研业务项目(2017Z017)资助

摘　　要：利用WRF模式、地基GPS资料以及常规气象观测资料,结合模式输出资料的高空间分辨率(10km)和GPS大气可降水量(GPS-PWV)资料的高时间分辨率(30min)的优点,对2008年7月20—22日四川盆地一次暴雨过程的水汽变化特征及各物理量与大气可降水量的关系进行综合分析。结果表明:此次降雨过程是由高原涡和西南涡共同作用引起,WRF模式能够较好地模拟出降雨落区和强度。GPS-PWV反映的大气可降水量增减趋势与WRF模拟的较为一致。水汽密度垂直分布反映了大气可降水量分布,水汽密度随高度增加而递减,降雨初期,水汽密度随高度减小迅速,降雨强盛时期,水汽密度随高度减小的速度减慢。水汽辐合使得水汽密度和大气可降水量增大,风的散度项与水汽通量散度的变化一致,而水汽平流项对水汽辐合贡献较小,水汽的辐合主要由风场辐合造成。By using the WRF model,ground-based GPS data,and conventional observational data,combining with the high spatial-resolution（10 km）WRF model output data and high time-resolution（30 min）GPS-Precipitable Water Vapor（GPS-PWV）data,a heavy precipitation process in the Sichuan basin is synthetically analyzed,especially on the vapor variation characteristics and the relationship between various physical quantities and GPS-PWV data.The results show the heavy precipitation event was caused by the interaction of the plateau vortex and the southwest vortex,and the WRF model can simulate the rainfall area and intensity well.The increase and decrease trends of atmospheric precipitable water vapor simulated by WRF fit with GPS-PWV.The vertical distribution of water vapor density reflected the distribution of precipitable water vapor,and the water vapor density decreased while the height increased.At the beginning of the precipitation,the water vapor density decreased quickly while the height increased.At the strong stage of the precipitation,the water vapor density decreased slowly while the height increased.The water vapor convergence resulted in the increasing of water vapor density and precipitable water vapor.The change of the divergence term of the wind agreed with the vapor flux divergence.The advection term of the water vapor had less contribution to the water vapor flux convergence.The convergence of the water vapor was mainly caused by the convergence of the wind field.

关 键 词：WRF模式 地基GPS 暴雨 大气可降水量(PWV) 水汽 

分 类 号：P458.1[天文地球—大气科学及气象学]