Improving the Nowcasting of Strong Convection by Assimilating Both Wind and Reflectivity Observations of Phased Array Radar:A Case Study  

作　　者：Xiaoxia LIN Yerong FENG Daosheng XU Yuntao JIAN Fei HUANG Jincan HUANG 

机构地区：[1]Guangzhou Institute of Tropical and Marine Meteorology/Guangdong Provincial Key Laboratory of Regional Numerical Weather Prediction,Chinese Meteorological Adminstration,Guangzhou 510641 [2]Guy Carpenter Asia-Pacific Climate Impact Centre,School of Energy and Environment,City University of Hong Kong,Hong Kong 999077 [3]Zhuhai Meteorological Bureau,Zhuhai 519000 [4]Foshan Meteorological Service of Guangdong Province,Foshan 528200

出　　处：《Journal of Meteorological Research》2022年第1期61-78,共18页气象学报（英文版）

基　　金：Supported by the National Natural Science Foundation of China(U1811464 and 40675099);National Key Research and Development Program of China(2018YFC1506900)。

摘　　要：With the advent of the phased array radar(PAR)technology,it is possible to capture the development and evolution of convective systems in a much shorter time interval and with higher spatial resolution than via traditional Doppler radar.Research on the assimilation of PAR observations in numerical weather prediction models is still in its infancy in China.In this paper,the impact of assimilating PAR data on model forecasts was investigated by a case study of a local heavy rainfall event that occurred over Foshan city of Guangdong Province on 26 August 2020,via a series of sensitivity experiments.Both the retrieved three-dimensional wind and hydrometeor fields were assimilated through the nudging method with the Tropical Regional Assimilation Model for South China Sea_Rapid Update Cycle_1km(TRAMS_RUC_1km).The temperature and moisture fields were also adjusted accordingly.The results show that significant improvements are made in the experiments with latent heat nudging and adjustment of the water vapor field,which implies the importance of thermodynamic balance in the initialization of the convective system and highlights the need to assimilate PAR radar observations in a continuous manner to maximize the impact of the data.Sensitivity tests also indicate that the relaxation time should be less than 5 min.In general,for this case,the assimilation of PAR data can significantly improve the nowcasting skill of the regional heavy precipitation.This study is the first step towards operational PAR data assimilation in numerical weather prediction in southern China.

关 键 词：phased array radar data assimilation INITIALIZATION nudging 

分 类 号：P412.25[天文地球—大气科学及气象学] P45