【摘要】 基于全球数值预报模式，利用格点同化系统（Grid point Statistical Interpolation system,GSI）将中国区域2170个地面自动气象站进行数据同化，建立了中国区域新的模式初始场，对比了中国区域气温、气压和风速3种气象要素的背景场和初始场特征以及同化后预报效果与欧洲中心再分析数据差异。结果表明：尽管仅仅同化了中国区域的观测数据，但同化后的模式平均偏差、均方根偏差和代价函数均显著降低，表明同化地面观测站资料能有效地降低模式背景场中的气温、气压和风速等基本物理量的误差，使模式的初始分析场和实际观测场更为一致；而在中国区域，3种气象要素的预报中气压的预报效果最好，7个区域气压的相关系数均达0.94以上，且同化后7个区域的相关系数均有提升，东北、华东等区域相关系数高达0.99；各区域气温的相关系数在同化后也略有提高，均方根误差在同化后有所降低，其中华南地区降幅最大，降低了2.3%。相对气压和气温而言，经向风和纬向风同化后改进不大，与再分析数据的相关系数偏小，同时均方根误差较大。其中，华东、西南和华中区域的经向风相关系数低于0.5，东北地区的经向风和纬向风的均方根误差均大于5 m s^-1。更多还原

【Abstract】 Based on global numerical forecast model,2170 surface automatic weather stations in China were assimilated by using Grid point statistical system （GSI） and a new model initial field was established.The characteristics of the three main meteorological elements in background field and initial field were compared with ERA5 reanalysis data over China,respectively.The results show that the mean deviation,root-mean-square error （RMSE） and cost function of the model are significantly reduced after the assimilation of surface automatic weather station observations in China,which indicates that the assimilation of ground observation station data can effectively reduce the errors of meteorological elements such as temperature,air pressure,and wind speed in the background field of the model,so that the initial analysis field of the model is more consistent with the observation field.In China,the prediction effect of atmospheric pressure is the best among the three meteorological elements.The correlation coefficients of atmospheric pressure in seven regions are all above 0.94,and the correlation coefficients of seven regions are improved after assimilation,and the correlation coefficients of Northeast and East China are as high as 0.99.The correlation coefficient of temperature in different regions increased slightly while the RMSE decreased after assimilation,especially in South China.Compared with atmospheric pressure and air temperature,the meridional wind and zonal wind improved less after assimilation,and the correlation coefficient with the reanalysis data is small while the RMSE is large.The correlation coefficient of meridional wind speed in East China,Southwest China and Central China is lower than 0.5 while the RMSE of meridional wind and zonal wind speed in northeast China are both greater than 5 m s^-1.更多还原