(c) Correlation coefficient between area-averaged precipitation over the southwestern Tibetan Plateau (SWTP; green polygon) and precipitation over the entire study region (1951–2007, APHRODITE).Dots in b,c indicate statistically significant areas (P(a) Time series of standardized anomalies in summer mean precipitation over the southwestern Tibetan Plateau (SWTP; green) and central-eastern India (CEI; purple) using APHRODITE (1951–2007) and TRMM (1998–2013).
Several lines of evidence confirm both the existence of the up-and-over moisture transport path and its importance in the water budget of the SWTP, including satellite measurements, isotopic ratios in precipitation, numerical sensitivity simulations and backward trajectory calculations.
Evidence of a strong connection between rainfall over the SWTP and rainfall over the Indian subcontinent emerges from historical records of precipitation (Fig. In particular, despite a large difference in rainfall magnitude across the Himalayas (Fig.
1a), significant decreasing trends have been observed over both the SWTP and central-eastern India (CEI; Fig. Decreases in rainfall over the Indian subcontinent over the past six decades have been attributed both to natural variability.
(b) As in a but for daily precipitation from TRMM during June–September 2002.
The light blue shading marks days with intrusive CSs, while the light orange shading marks days with non-intrusive CSs.