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利用1948-2010年全球GPCC月平均降水,GHCN_CAMS月平均气温资料,GLDAS-NOAH月平均、3 h土壤湿度和降水资料以及观测资料,分析了土壤湿度与降水和气温之间的关系.结果表明:全球土壤湿度记忆性的时间尺度在20~110 d不等,干旱地区浅层(0~10 cm)土壤湿度记忆性较短,中深层(10~200 cm)较长,湿润区及高山地区土壤湿度记忆性均较长,北半球春季土壤湿度记忆性最长,南半球夏季土壤湿度记忆性最长;降水和气温对同期土壤湿度在不同地区的作用不同,北半球夏、秋季降水是土壤湿度的主要来源,除非洲干旱区以外的中低纬度地区及南半球,土壤湿度随降水的增加而增加,随气温的升高而减小;浅层土壤湿度受同期降水和气温的影响最为显著;前期降水和气温对土壤湿度的影响存在着较大的空间差异,北半球中高纬度地区,当年的夏、秋季降水是次年春季土壤湿度的主要来源,中层土壤(10~100 cm)是降水的主要存储层.浅层土壤受外界影响较大,对前期气候信息的存贮有限.中低纬度地区及南半球,中深层土壤更多地是存储前一个季节的气温和降水信息,对跨季节气候信息的存储并不明显;低纬度地区春季土壤湿度的增加可能有利于后期降水的增多,高纬度地区春季土壤湿度的增加可能使后期降水减少,在季节尺度上中层土壤湿度对后期的降水影响较明显,在月至日尺度上浅层土壤湿度对后期降水的影响更重要;春季干旱区尤其是中层土壤湿度的增加可能有利于夏季气温的降低.
The relationship between soil moisture and precipitation and air temperature was analyzed using the global average monthly rainfall of GPCC, the average monthly temperature of GHCN_CAMS, the monthly average of GLDAS-NOAH, the 3-h soil moisture and precipitation data and the observed data from 1948 to 2010. The results show that: The time scale of global soil moisture storage ranged from 20 to 110 days. The soil moisture in the shallow (0-10 cm) of the arid region was memorized in a short time, while the middle and deep layers (10-200 cm) were longer. The humid and alpine regions of the soil Humidity memory is longer, the highest in the northern hemisphere spring soil moisture memory, the longest in the southern hemisphere summer soil moisture memory; precipitation and temperature on the same period the role of soil moisture in different regions, summer and autumn in northern hemisphere rainfall is the main source of soil moisture , The soil moisture increased with the increase of precipitation and decreased with the rise of temperature in the middle and low latitudes except in the arid regions of South Africa and the southern hemisphere. The soil moisture in shallow soil was most significantly affected by precipitation and temperature in the same period; There is a large spatial difference in soil moisture. In the middle and high latitudes of the northern hemisphere, the summer and autumn rainfall in the northern hemisphere is the main source of soil moisture in the following spring. The middle soil (1 0 ~ 100 cm) is the main storage layer of precipitation.The shallow soil is greatly affected by the outside world, and has limited storage of previous climate information.Moreover, in the middle and low latitudes and in the southern hemisphere, the middle and deeper soils are more likely to store the temperature of the previous season And precipitation information, the storage of inter-seasonal climate information is not obvious; the increase of spring soil moisture in low latitudes may be conducive to the increase of late precipitation, and the increase of spring soil moisture in high latitudes may reduce the precipitation in later stage. On the seasonal scale, The influence of soil moisture on later precipitation is more obvious. The influence of shallow soil moisture on later precipitation is more important in the month-to-day scale. The increase of spring soil moisture, especially the middle soil moisture may be beneficial to the decrease of summer temperature.