基于GLDAS的中国区地表能量平衡数值试验

Numerical experiments of surface energy balance over China area based on GLDAS

利用全球陆面数据同化系统(GLDAS)的软件平台—陆面信息系统(LIS)模拟了中国区域2003年能量平衡方程的各个分量,在此基础上进行了残差分析和地表温度的对比验证。残差的分布具有一定的时空分布特征,残差的时间分布特征表明LIS对春秋两季的模拟效果要好于其它季节,残差的空间分布特征表明LIS对纬度较高和海拔较高地区的模拟效果要逊于其他地区。对比了模拟的GLDAS地表温度与MODIS地表温度产品,结果显示两者之间的差值介于-5～5K之间,两者的散点图和标准离差显示模拟的夜间地表温度要比模拟的白天地表温度精确2～3K。

In the absence of the long-term observations of the components of the water and land surface energy budgets, modeling can provide consistent fields of the land surface fluxes and states. We simulate the components of surface energy balance （SEB） equation using the land information system （LIS） of the global land data assimilation scheme （GLDAS） during the period of Novenben 2002 to Decenbero 2003 in China. The residual analyses of SEB indicate that the residuals distribution （RD） shows some spatial and temporal characteristics. The temporal characteristics of the RD suggest that LIS can simulate energy flux better in spring and summer than in other time. The spatial characteristics of the RD indicate that LIS can simulate energy flux better in places with relatively low latitude or low altitude than in the places with either the relatively higher latitude or higher altitude. This kind of the temporal and special distribution pattern is probablv related to the parameterization of snow albedo. The results of the comparison between simulated DLDAS and MODIS land surface temperature（LST） indicate that the main difference between two LST are within ± 5K. The scatter plots and standard deviation suggest that the simulated LST of night is 2 - 3K more accurate than that of day time.