Precipitable Water Data Are Applied In The Assimilation Of Numerical Model

It is well known, Moisture is the basic condition for precipitation. Water vapor content of both the number could reach saturation point decision, The same size directly related to precipitation. In recent years,GPS has opened up a foundation to improve the possibility of monitoring of water vapor in the atmosphere. GPS data analysis using a combination of network parameters to measure the earth. The results show that, GPS can be derived rainfall is relatively high accuracy. GPS has high time density,it can be able to provide 30-minute intervals for the measurement results, At the same time its high density of space, Can point-intensive cloth.We take a heavy rainfall process during 4-5,June,2006 as the experimental research object, use the genetic algorithm assimilation system ,and carry out data assimilation experiment of GPS precipitable water data. And to do with the comparision experiment of adioint 4DVAR model. It is find that the heavy rain event was close related to generation and development of mesoscale vortex in the mid-low troposphere .The environmental condition between the southern edge of tge westerlies and northern rim of the subtropical high of the western Pacific is favorable for the development of Mesoscale Convective Systems(MCSs)and the occurrence of heavy rain.MCSs develop continuously over there while the low-level jet transports warm and moisture air to the south of MCSs.the effect of numerical simulation with GPS precipitable water(GPS) data is better than without GPS. To further test the use of genetic algorithm for the effects of assimilation system, Through the RMS experiments of the humidity, wind and high field ,prove the experiment adding GPS can directly improve the other elements' forecasts obviously comparing that adioint 4DVAR model, can simulate the structure of lower wind field and humidity field that is more close to the real fact,it can improve the districts and the strength of the heavy rain.