Study on Spatially Averaged Evaporation under Soil Moisture Heterogeneity Affected by Permafrost Micro-topography

[摘要] We discuss the effect of the soil moisture heterogeneity on the spatially averaged fluxes in the Tibetan Plateau. Using the observational data obtained during the GAME/Tibet Pre-phase Observing Period (POP) in 1997 and the Intensive Observing Period (IOP) in 1998, we show the seasonal variability of the soil moisture distribution. The water and energy flow processes in the permafrost region are studied. Based on the observational results, the 1-D heat and water flow model is applied to the Tibetan Plateau. This model demonstrates the seasonal variability of soil moisture distribution. To examine the effect of the soil moisture distribution, spatially averaged evaporation is calculated by this model in two different ways: one by using the spatially averaged soil moisture and the other by considering the soil moisture heterogeneity. We compare with two kinds of the spatially averaged evaporation. The comparison indicates that it is important for the estimation of spatially averaged fluxes to consider the effect of soil moisture heterogeneity.

[学科分类] 大气科学