Evaluation of summer climate simulations over east Asia by a variable resolution model LMDZ

A variable resolution regional climate model LMDZ is used to simulate May-September climate during 1979—2008.The model was forced by the outputs of LMDZ-Global,observed sea ice and sea surface temperature data and its center of zoom was modified and set at 37 °N,112.5 °E.Based on the NCEP/NCAR reanalysis data and gridded observation data in Chinese region promoted from original meteorological stations' data in China,the LMDZ regional climate model was evaluated in tems of its summer mean climate over east Asia.Results show that: the distribution characters of 500 hPa geopotential height and 850 hPa temperature are well simulated,however the values are a little lower than the actual;the simulated subtropical high intensity is weaker and its position tends to east.It can reproduce well the atmospheric circulation over east Asia.The main distribution of simulated surface air temperature and precipitation over China are basically reasonable.The simulated biases of surface air temperature show that it is equal with the actual in the central and north-east China,whereas colder than the observations by 1～3 ℃ in southeast coastal region and 3～4 ℃ or more in western China.The simulated and observed precipitation are consistent in most areas in northwest China,and its bias of larger rainfall is found mainly in simulated China's southeastern coastal area.Concerning the 7 sub-regions,the model reproductions of the 850 hPa temperature and surface air temperature are better than the simulation of 500 hPa geopotential height and precipitation.The biases between simulation and observation differ in each subarea.North and northwest China have the minimum deviation of surface air temperature and precipitation respectively.