A land surface model (IAP94) for climate studies part II: Implementation and preliminary results of coupled model with IAP GCM

The Institute of Atmospheric Physics Land Surface Model (IAP94) has been incorporated into the IAP two-level atmospheric general circulation model (IAP GCM). Global and regional climatology averaged over the last 25 years of 100 year integrations from the IAP GCM with and without IAP94 ("bucket" scheme) is compared. The simulated results are also compared with the reanalysis data. Major findings are: (1) The IAP GCM simulation without IAP94 has extensive regions of warmer than observed surface air temperatures, while the simulation with IAP94 very much improves the surface air temperature. (2) The IAP GCM simulation with IAP94 gives improvement of the simulated precipitation pattern and intensity, especially the precipitation of East Asian summer monsoon and its intraseasonal migration of the rainbelts. (3) In five selected typical regions, for most of the surface variables such as surface air temperature, precipitation, precipitation minus evaporation, net radiation, latent heat flux and sensible heat flux, the IAP GCM with IAP94 provides better simulations.