Seasonal and interannual variability of atmospheric water balance and river runoff are compared from region to region in Asian monsoon region based on the GAME-reanalysis and NCEP/DOE reanalysis data. The characteristic nature of variability in each region/river basin are discussed in terms of land(and ocean) surface conditions, atmospheric circulation field. The role of widely-distributed rice paddy field in east ans southeast Asia has been suggested to play an important role on the variability of the Precipitation (P)-Evapotranspiration(E)-Moisture Convergence(C) relations. The possible role of boreal forest in Siberia on the variability will also be disucussed.
In the Yantze river basin in China, for example, interannual variability of P changes depending upon C, but basic amount of P is supplid by E from the surface, which may closely related to the water-fed rice paddy field of this region. Intersetingly, the similar situation is dominated in the Taiga-permafrost zone of Siberia (Yasunari and Yatagai, 2001), where the fores plays an importand role of water storage. In southeast Asia, this P-C-E relation in terms of land surface condition seems to be different from those in mid and high latitudes, presumably because of relatively large role of C associated with the monsoon flow.
