Moisture source anomalies connected to flood‐drought changes over the three‐rivers headwater region of Tibetan Plateau

Abstract

The Flood‐Drought condition over the Three‐River Headwater region (TRHR) of the Tibetan Plateau (TP) exerts vital impacts on regional climate and downstream livelihoods. However, the reasons behind precipitation variability over this region remain elusive. In this study, the multi‐year moisture sources of water vapour reaching the TRHR were identified to reveal their connection to the interannual variability of summer precipitation by utilizing a Lagrangian diagnosis analysis. The results show that the moisture sources could be tracked backward covering vast areas, with the peak values located mostly at the northern Indian continent and adjacent regions of TRH itself. The variability of integrated moisture sources' contribution agrees well with the summer precipitation on the interannual scale; However, the role of different regions varies in line with their geographical location. More specifically, summer precipitation is positively correlated with the moisture source over the adjacent areas of TRH and the remote terrestrial‐oceanic regions, in contrast to a negative correlation to the water vapour departing from the Northeastern Asian and western regions to the TP. The Indian summer monsoon circulation and local recycling process play a dominant role in modulating the summer precipitation on the interannual scale, whereas the role of the westerlies is almost negligible. The abnormal atmosphere circulations triggered by mid‐high latitude wave trains and anomalies in SST in the central and eastern Pacific Ocean and Indian Ocean could serve as possible drivers for the precipitation variability over TRHR.

Impacts of Extreme Precipitation and Diurnal Temperature Events on Grassland Productivity at Different Elevations on the Plateau

“…The elevation ranges between 1650 and 6860 m. The climate in Qinghai Province is predominantly characterized by two climatic zones: the semiarid alpine climate and the cold temperate semi-humid climate, which display noticeable fluctuations in temperature and precipitation levels concerning changes in elevation. In addition, with a vast coverage of grasslands in most areas of Qinghai Province, encompassing almost all grassland types found in the plateau region, this area serves as a representative of the climatic conditions in both Northwest China and the Qinghai-Tibetan Plateau [22,23]. The grassland types include temperate grasslands, alpine grasslands, alpine meadows, and desert grasslands, each displaying distinct characteristics along different altitudinal gradients (Figure 1).…”