Moisture sources for South Asian monsoon precipitation from CMIP5 simulations

South Asian monsoon is the most prominent and dynamical system among the global monsoon systems. During the summer monsoon, evaporation from Arabian Sea, Bay of Bengal and local land areas brings moisture to the continent that eventually precipitate as monsoon rainfall. However, it is not very clear that how much do each of these moisture sources (local, Arabian sea and Bay of Bengal) contribute to the seasonal precipitation in the summer season. To answer this question, we apply a Lagarangian analytical model to track the moisture that contributes to the South Asian continental monsoon precipitation but evaporates from a large domain [0-150E, 30S-45N]. The analysis domain that includes all the three source regions of interest can explain over 90% of the moisture sourcing over South Asian land during the summer monsoon season in the NCEP/NCAR Reanalysis data. Overall, most of the moisture comes from the local recycling, followed by the contributions from Arabian Sea and Bay of Bengal. Further, we analyze data from Global Climate Models (GCMs) of Coupled Model Intercomparison Project Phase 5 (CMIP5) for both the historic (1965-2005) and the 21st century projection (2010-2050) periods under the Representative Concentration Pathway 8.5. to investigate 1) GCMs ability in the representation of these moisture sources over South Asia, and 2) the impacts of increase in greenhouse gas forcing on the moisture transport from the three sources and their relative role in the projected summer monsoon changes over the South Asian land region.