Signatures of Indian monsoon dynamics in daily GRACE data

Temporal variation in the gravity is being observed by GRACE/GRACE-FO mission since 2002, at different temporal scales, ranging from daily to monthly. Daily GRACE data has a course spatial resolution, but it can be used for analyzing large-scale atmospheric and meteorological phenomena, for example, monsoon. An inter-comparison of daily precipitation (GPCC) and GRACE(-FO) datasets shows a significant correlation between the two datasets with a lag of 20 days. The inter-comparison between GRACE and GPCC data distinctly captured characteristic features of the monsoon. Both the data are being used to track the Indian monsoon, its onset and demise using change point analysis, duration, region which is most affected and to reproduce detailed features of Indian monsoon. This study has also analyzed the long-term Spatio-temporal changes in rainfall and its relation with mass variation using the data across India at meteorological divisional level. This study with data of two different sources has shown sufficiently promising results and significant agreement between them, particularly the duration and the path of the monsoon.