Large-scale circulation dominated precipitation variation and its effect on potential water availability across the Tibetan Plateau

Abstract

The large-scale circulation, Indian summer monsoon (ISM), has a strong influence on the Tibetan Plateau (TP) since its onset and intensity have profound impacts on regional precipitation, which then can supply water for glaciers, lakes, rivers and social demands. Weakening monsoon intensity and longer monsoon duration seem contradictory, as a weaker monsoon tends to produce less precipitation, while a longer duration increases the probability of precipitation. Past research has focused on how ISM’s intensity affects precipitation, with little consideration of the impacts of ISM duration. Here, we investigated the long-term (1979–2100) variability in the ISM’s duration and intensity. We found a prolonged ISM from 1979–2018, accompanied by monsoon weakening. Different combinations of duration and intensity have resulted in different spatial patterns of precipitation across the southeastern TP. Weakening and proglonged ISM is helpful to produce more precipitation around the southeastern TP, with intensity acting as a dominant control. Afterwards, an obvious impact can be found on potential water availability. Climate projections suggest that the ISM will weaken and lengthen until 2100, thereby increasing precipitation and potential water availability across the southeastern TP. This long-term trend should receive more attentions as increased regional extreme precipitation will increase the probability of flood risks until the end of this century.

Hydrological Projections in the Third Pole Using Artificial Intelligence and an Observation‐Constrained Cryosphere‐Hydrology Model

“…Additionally, it benefits from the meltwater generated from Himalayan glaciers and snow (Scanlon et al., 2023; Q. Zhang et al., 2023). Similarly, the southeastern part of the Brahmaputra features a significant atmospheric water vapor corridor, facilitating the influx of warm and moist air masses from the Indian Ocean in a northwestward direction, resulting in abundant precipitation (X. Li et al., 2023; Yuan et al., 2023). Additionally, the presence of maritime glaciers in this region contributes significantly to runoff, accounting for approximately 10% of its total contribution (X. Chen et al., 2017; Kraaijenbrink et al., 2021; F. Zhao et al., 2022).…”

Comparative analysis of indices in capturing the onset and withdrawal of the South Asian Summer Monsoon

“…The onset of the South Asian Summer Monsoon (SASM) at the southern tip of India marks the commencement of the rainy season, with over 90% of the region's annual rainfall occurring during this period (Li et al 2023). The SASM has a significant influence on the socioeconomic development of South Asian and neighboring regions.…”