Recent increase in Tibetan Plateau lake volume driven by earlier onset and intensification of Asian summer monsoon
Abstract
The Tibetan Plateau (TP) plays an essential role in the water supply to Asia's large river systems and, as the largest and highest mountain plateau in the world, it drives the Asian monsoon and influences global circulation patterns significantly. The increase in TP lake level since the mid 90s is well documented in the literature, however the drivers of these changes remain relatively unexplained.
In this study we investigate two potentially important contributors to lake level rise: glacier mass loss and changes in the precipitation regimes. We demonstrate that glacier mass loss is a non-negligible contributor of the lake volume increase, with contributions up to a maximum of 30 ± 10 % for selected basins. However, for the majority of basins analyzed, it explains only a fraction of the total lake volume increase. We show that the lake volume change is primarily driven by an increase in precipitation during the summer months (JJA) for the entire TP. In addition, on the south-eastern fringe of the TP, where the lake volume increase is most pronounced, a considerable additional increase in May precipitation is observed since the mid 90s. The underlying reason for the (pre-)monsoon wetting of the TP may well be related to global warming patterns, but the exact mechanisms for this intensification remain largely unclear.- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2019
- Bibcode:
- 2019AGUFMGC42B..01I
- Keywords:
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- 1616 Climate variability;
- GLOBAL CHANGE;
- 1621 Cryospheric change;
- GLOBAL CHANGE;
- 1631 Land/atmosphere interactions;
- GLOBAL CHANGE;
- 1655 Water cycles;
- GLOBAL CHANGE