Terrestrial water storage changes of the 2010 southwest China drought detected by GRACE temporal gravity field

Presently global and regional terrestrial water storage (TWS) changes can be observed by the Gravity Recovery and Climate Experiment mission (GRACE). The TWS changes over southwest China was inferred from the GRACE monthly gravity field models over the period 2003-2010, and consist with the results of Global Land Data Assimilation System (GLDAS) on spatio-temporal distribution. The significant decrease of TWS from autumn 2009 to spring 2010 revealed by GRACE coincides with the 2010 southwest China drought conditions. And the spatial distribution of monthly precipitation from the combined data of Tropical Rainfall Measuring Mission (TRMM) is consistent with the GRACE results during the time span from autumn 2009 to spring 2010. By analyzing the correlation between monthly precipitation and TWS changes, the results with the correlation coefficient of 0. 569 reveal that precipitation is the main cause of TWS changes. Meanwhile the surface air temperature over the region from September 2009 to March 2010 is a little higher than that of the same time in history, and then the warmer ground surface made the TMS decrease slightly.