The High Resolution Climatic Simulation And Evaluation In The Three Gorges Area Based On WRF Model Combined With Assimilating Automatic Weather Station Data

In this paper, based on the WRF (Weather Research Forecast) model and its own Nudging assimilation system and method.The automatic station observation data assimilation after a series of quality control of the encrypted automatic stations in January and July 2014 in the Three Gorges area were assimilated,establishted the 3km high resolution air temperature field, relative humidity field and wind field in the Three Gorges region in January 2014 and July 2014. And its result with the results of the non-assimilation test and the sparse field assimilation test of the NCEP sparse observation site are compared and analyzed.And the three tests are compared and evaluated with the actual observation data at the same time.And the improvement effect of assimilation data compared to the actual observation in different terrain of plain,hills and mountain are analyzed.The results show:(1) Quality control of the Three Gorges area of the automatic station observation data makes effective screening and investigation, established the necessary basis for the automatic station assimilation test.(2) The simulated effect of WRF model assimilation automatic station on temperature field, relative humidity field and wind field is better than that of non-assimilation test and sparse field assimilation test. The sparse field assimilation test is superior to the non-assimilation test, and the simulation results of automatic station assimilation test has significant improvement when compared with the other two tests.(3) Compared the simulation results of temperature field, relative humidity field and wind field.The establish results of high resolution of the temperature field of WRF model assimilation automatic station test in January 2014 and July 2014 has the best effect, After assimilating automatic station , compared to the actual observed monthly mean temperature field, the temperature deviation in most areas is reduced to ± 0.5 ? or less, daily and hourly temperature correlation coefficient between daily temperature change series and observation sequence increased to 0.9 and above,which provides an effective reference to establish high resolution temperature field in the region; and the result of relative humidity field is better than the wind field.(4) Compared the simulation results improvement of temperature field in plain ,hills and mountain, it shows that the improvement is the most significant in hills in January,followed by mountain;And the improvement is the most significant in plain in July ,also followed by mountain.In the simulation results improvement of relative humidity field in the January, the improvement in hills is more significant than plain,and the improvement in plain is more significant than mountain. And in July ,the improvement is similar in plain and hills,and their improvement are both more significant than mountain. In the simulation results improvement of wind field,the improvement in hills is more significant than mountain,and the improvement in mountain is more significant than plain in both two months.(5) Considering the difference between the terrain of the model and the automatic station observation,the spatial distribution of air temperature and the daily,hourly temperature statistical test results was revised according to the terrain altitude difference.After the revising ,the effect of improment is very significant.