用全球大气混合层海洋环流模式模拟二氧化碳增加对土壤湿度季节变化的影响

SEASONAL CHANGES OF SOIL MOISTURE INDUCED BY DOUBLED CO_2 AS SIMULATED BY THE AGCM/MIXED-LAYER OCEAN MODEL

本文利用全球三维大气耦合混合层海洋环流模式模拟大气中二氧化碳浓度增加对土壤湿度的影响。敏感试验(2×CO_2)与控制试验(1×CO_2)对照表明,当大气中二氧化碳浓度增加时,全球土壤湿度在各季发生明显变化。其中两半球低纬度地区在冬季土壤温度变温,两半球中纬度地区则在各季土壤湿度变干,北半球高纬度地区土壤湿度在夏季变干,其余各季变温。分析大气中二氧化碳浓度增加造成土壤温度全球变化的可能物理机制表明,地面水循环和热量循环是重要的因素。

The atmospheric general circulation model coupled to the mixed layer ocean model has been used to simulate the changes of the global soil moisture. Comparing the simulated results with observations, it is shown that the model is capable of doing sensitive experiments about the carbon dioxide changes.The 2×CO2/1×CO2 comparison shows that there are the obvious changes of the soil moisture in the global for four seasons. There are the wet soil moisture in the lower latitudes of both hemispheres and dry soil moisture in the middle latitudes of both hemispheres for four seasons. The dry soil moisture in summer and wet in other seasons are found in the northern higher latitudes.The analyses of the physical mechanisms responsible for the CO2-induced changes of soil moisture show that the budgets of the surface water and heat are the important factors.