Spatial and temporal precipitation patterns characterized by TRMM TMPA over the Qinghai-Tibetan plateau and surroundings

Compared with traditional methods to investigate spatial and temporal precipitation patterns over mountainous regions with limited meteorological observations, satellite-based precipitation estimates provide much more information to aid in understanding spatial distribution and variability, especially on the Qinghai-Tibetan Plateau and surrounding regions (TP), where the precipitation climate has been insufficiently documented so far. The monthly Tropical Rainfall Measurement Mission (TRMM) Multisatellite Precipitation Analysis (TMPA) 3B43 V7 datasets, with high resolution (0.25°), were firstly applied in this study to investigate the spatial and temporal precipitation patterns over the TP, from 1998 to 2013. We found that the mean precipitation at the TP scale did not show clear trends at monthly, seasonal, or annual scales. We also found that precipitation over the TP shows different spatial variation trends at different temporal scales. For example, along the southern Himalayas, there is a clearly decreasing annual precipitation trend, with rates ranging from ?120 to ?20 mm/year, and the precipitation increases along the west coast of India to eastern Pamir, with rates larger than 20 mm/year. Another finding was that the precipitation climate over the TP is influenced by different atmospheric circulation patterns; the contribution of monthly and seasonal precipitation to total annual precipitation varies spatially. For instance, the annual precipitation along the southern Himalayas and the southeast TP mainly occurs in summer, and the northwest TP mainly receives precipitation in spring and winter.