DROP · Drivers and origins of high-altitude precipitation on the Third Pole

Asia’s mountain ranges are the world’s most important water towers, often referred to as the planet’s Third Pole. Precipitation in these mountains feeds glaciers and snow fields and generates river flow, which sustains millions of people downstream. Precipitation also triggers natural hazards such as floods, landslides and avalanches, which cause enormous human and economic losses. Despite the importance of high-altitude precipitation, we lack a fundamental understanding of the mechanisms that control its distribution and how it changes. We need this to elucidate the water cycle at the Third Pole. DROP will close this knowledge gap by showing how the mountains, feedback from land surfaces and large-scale circulation control the magnitude and spatiotemporal distribution of high-altitude snow and rain. New field observations at extreme altitudes and state-of-the-art atmospheric modelling will provide a comprehensive picture for the entire Third Pole at a wide range of scales.At the smallest scale, a high-altitude ice core and meteorological observations will provide key insights into past accumulation trends. At the valley scale, I will combine dense observations of precipitation and high-altitude snow accumulation with atmospheric simulations to gain insight into snow and rainfall patterns. At the scale of the entire Third Pole, I will conduct state-of-the-art atmospheric model experiments, combined with in-situ observations in regional transects and remote sensing to understand how the extreme topography, land surface feedback and moisture recycling control snow and rain patterns. DROP will provide a long-awaited scientific step forward in understanding mountain precipitation in a region where this is of vital importance for water security and disaster risk reduction for millions of people.