The Retrieved Wind Field From Single Doppler Radar Data By Using Twi-adjoint Method And Its Application On Study Of Mesoscale Heavy Rain Process

At present, Doppler radar is the most useful instrument to observemeso-scale weather system directly. Depending on its high density, wecan catch the fine structure of meso-seale weather system. But in mostarea, there is just one single Doppler radar. So, it is meaningful thatresearching retrieval method on the basis of single Doppler radarobservation data. Here, we put forward twi-adjoint method to retrievewind field from single Doppler radar: First, created initial wind fieldfrom routine sounder data using multivariate optimum interpolation, thenon the basis of it, make the aim-function infinitesimally without thebackground field restriction and the smoothness of three-dimensionalwind field restriction. Do it again adding the two disregardedrestriction condition and adopting the retrieved three-dimensional windfield as background field, we can get the three-dimensional wind fieldfinally. And,to analyze a meso-seale rain storm in the middle of Jiangsuprovince on June 2005 making use of the outcome. It can elementarily showus the reason of why the strong rainfall center existed through analyzingthe retrieval wind structure and some physical diagnoses. The resultexplained that the twi-adjoint method could show the characters ofmeso-scale rainfall relative clearly. Then we use WRF to simulate thismeso-scale rain storm to get high density data just like the retrievaldata, and to compare their three-dimensional wind field. The consistentoutcome shows that the twi-adjoint method is reasonable and useful.