Spatial Distribution And Temporal Variation Of The Observed And Simulated Soil Moisture Over China

As one of the important variables in the land surface process, soil moisture (SM) plays important roles in the climate through affecting the surface albedo, thermal capacity, latent heat, and sensible heat, etc. SM is the most important factor for the climate change next to the sea surface temperature. This study investigates the spatial distribution and temporal variability of the SM in China using both the observation data and the model output. Firstly, water vapor budget over the land surface of eastern China and three sub-regions (i.e. the northern China, the Yangtze River Valley, and the southern China) are evaluated by using monthly station data and two reanalysis data (i.e. ERA40 and NCEP/NCAR reanalysis). In the background of understanding the water vapor budget over the land surface, the SM of two reanalysis and two land surface models is evaluated over China using few observations. And a"observation"standard of SM which can be used in evaluations of simulations is confirmed form observations, two reanalysis and two land surface models. Then, SM simulated by coupled models is evaluated over China. After that, changes of SM over China were analyzed using the simulation under the global warming scenario of 10 coupled models as participants in IPCC (Intergovernmental Panel on Climate Change) AR4 (Assessment Report 4). Finally, the effects of SM on the East Asia summer climate are analyzed using the numerical simulations of RegCM3 (Regional Climate Model).The main conclusions are summarized below:1. Evapotranspiration (E) is larger than precipitation (P) in annual mean and summer mean. In winter, E seems to be equivalent to P in eastern China. Northern China is a moisture source in context of annual, summer, and winter mean, while the...