The simulation of soil moisture, evapo-transipitation, and river runoff by using land surface scheme and climate model are the big issues for the climate research and the seasonal forecast. But the amount of the precipitation is often not simulated well in climate model. The error of the precipitation makes those biases worse. We are interested in the relationships and started investigations about the impacts of the precipitation on them.

The using data are the GSWP2 forcing data, and the model is the off-line version of our new land surface scheme. The model has been improved from JMA/SiB. The major improved points are : the number of snow layers is 4 at the maximum from 1, and the phase change of soil water is included.