completed · WASH· Health

Past-present-future Monsoon variability revealed by stable water isotopes: combining observations and climate models to assess its impacts on Bhu

The present project focuses on understanding the processes that govern the variability of the South Asian Monsoon over various time-scales from days to decades. We have chosen to focus primarily on the monsoon impacts in Bhutan, with a planned extension of the study area to neighbouring Nepal: this region is mainly affected by the Indian Monsoon subsystem, but it is likely to be influenced by the South-East Monsoon subsystem as experienced e.g. in Thailand. We emphasise in particular the use of stable water isotopes (SWI) to better understand and constrain processes in the atmospheric water cycle. The suggested approach combines ground- based (precipitation sampling, shallow ice-cores) and remote-sensed (tropospheric vapour) ob- servations with global and regional climate models with embedded SWI diagnostics. The periods of interest cover present-day, recent (1981-2010) and future (2021-2050) Mon- soon variability. Beyond the inherent scientific challenges in improving our understanding of the Asian Monsoon, the present project is highly relevant for supporting sustainable develop- ment policies in the partner countries. Analysing the regional SWI signature will also contribute to a refined interpretation of isotopic climate archives in Southern and Eastern Asia.