气象学报2018，Vol.76Issue(3)：343-360,18.DOI:10.11676/qxxb2018.008
基于西南涡加密探空资料同化的一次奇异路径耦合低涡大暴雨数值模拟研究
A numerical study on a heavy rainfall caused by anabnormal-path coupling vortex with the assimilation of southwest China vortex scientific experiment data
摘要
Abstract
Using the Weather Research Forecast (WRF)model and WRF data assimilation system (WRFDA),sensitivity ex-periments are conducted to simulate a heavy rainfall caused by the coupling of the Tibetan Plateau vortex (TPV)and an abnor-mal-path southwest China vortex (SWCV)in Sichuan Basin with assimilation of operational sounding data and the intensive ob-served data obtained through the SWCV Scientific Experiment.The model simulations of precipitation and the vortex moving path using different initial conditions are compared,and the impacts on the structure evolution of the SWCV and associated pre-cipitation by assimilating intensive sounding data are analyzed.The results show that the model capability for the forecast of precipitation and the moving paths of TPV and SWCV is improved by assimilating both intensive sounding data and convention-al sounding data,while the forecast is less satisfactory with assimilation of only the conventional sounding data.By introducing intensive sounding data,the intensities of initial TPV and SWCV are enhanced due to the increased cyclonic perturbation on the initial wind field.In addition,the more unstable stratification adjusted by data assimilation makes it easy for the model to pro-duce large precipitation with a magnitude that is consistent to observation at the initial time.The experiment reveals that the generation and maintenance of the SWCV at 700 hPa in this case not only rely on high potential vorticity in the upper levels,but also rely on increases in positive vorticity caused by horizontal convergence in the lower levels and its upward transport,which is favorable for the SWCV to develop and move.Latent heat release associated with precipitation at the beginning of the simula-tion also plays an important role in the development of SWCV.Results of the present study are helpful for better understanding the mechanisms for the development of SWCV and associated precipitation process.关键词
西南涡/高原涡/WRFDA/西南涡加密探空资料/涡度方程Key words
SWCV/TPV/WRFDA/Intensive sounding data of SWCV/Vorticity equation分类
天文与地球科学引用本文复制引用
高笃鸣,李跃清,程晓龙..基于西南涡加密探空资料同化的一次奇异路径耦合低涡大暴雨数值模拟研究[J].气象学报,2018,76(3):343-360,18.基金项目
国家自然科学基金重点项目(91337215 )、国家自然科学基金面上项目(41275051 )、四川省应用基础研究重点项目(2016JY0046)、公益性行业(气象)科研专项项目(GYHY201006053). （91337215 ）
