The Characteristics And Inversion Of Wind Fiele With Doppler Radar Data In The Severe Precipitation

Short heavy rainfall happens frequently in Qinhuangdao because that it locates in the west of Bohai bay and the north of Yanshan Mountain and has complex terrain. Severe precipitations in the short time have its unique properties. In this paper, utilizing Micaps information, NCAR/ NCEP reanalysis data, Doppler radar, automatic weather station wind and precipitation data, using WRF model, the radar echo analysis, EVAD method, four-dimensional variation method, analyzing a short duration heavy rain occurred in 6 July 2009 in Qinhuangdao City, the main conclusions are as follows:(1)Using the WRF model simulate the heavy precipitation, the results shows that the simulated distribution of precipitation is close to the observation, but the rainfall in Qinhuangdao simulates weak. WRF model can simulate the trough moving eastward deepening with the strengthening the sea breeze, the simulated surface convergence line and moisture convergence center has obvious implications for heavy rainfall, but relevant physical quantities simulates a little weak. The reasons may be that the initial field data is density, when the model is interpolating, the smaller the weather system may be smoothed out. Therefore, using conventional data simulate small-scale systems in WRF model also has some limitations.(2)Analyzing the characteristics of Doppler radar reflectivity, vertical wind profile and radial velocity field in the heavy rainfall, the results show that the vertical wind profile radar products can reflect the atmospheric water vapor content changes in higher level; when the dry cold air in middle layer invades, the rainfall intensity increases; the instructions of Doppler radar's radial velocity field on heavy rainfall is earlier than the reflectivity.(3)Using EVAD method calculate the average atmospheric divergence, using the variation method calculate the average atmospheric vertical velocity, analyzing the dynamic process of the precipitation, the results show that the method can reflect the dynamic characteristics of the precipitation process, the severe convective weather would be brought out when there was strong convergence of low-mid level Jet Stream and with the severe ascending motion.(4)By four-Dimensional Variation Method (the data of two adjacent volume scan were input once in so-called 4DVM), to run the wind field interpretation, depending on the analysis for the severe precipitation of micro-and meso scale systems in the short time, the situation of micro-and meso-scale weather system can be reflected truly. The heavy rainfall occurred in the "people"(Chinese character) shaped shear line before the warm the shear line side, when the middle-y cyclonic circulation appears near the warn shear line, the precipitation will enhanced further more.