High-resolution Numerical Modelling to Investigate the Atmospheric, Glacial, and Hydrological Dynamics in the Himalaya

Abstract

Investigating the atmospheric, glacial, and hydrologic dynamics over the Himalaya is particularly challenging due to its complex topography and limited availability of station data. The uncertainties are further amplified by the profound impacts of global climate change, which significantly influence the region’s atmospheric, glacial, and hydrological responses. While global and regional climate models perform well over relatively flat terrain, they often fail to capture the spatial variability of the atmospheric field in the Himalaya. In this context, well-validated, process-based numerical models offer a promising alternative for studying these dynamics. The Weather Research and Forecasting (WRF) model used in this study is a dynamic atmospheric model used in both operational weather forecasting and atmospheric research. This study uses the WRF model to (a) improve extreme precipitation forecasting skills, (b) explore the intricate relationship between the topography and atmospheric dynamics, and (c) apply the well validated WRF output to drive a new glacial-hydrological model in the Himalaya. This study has demonstrated that the well validated WRF model can accurately reproduce the surface meteorological variables and provide insightful information to investigate the influence of topography in convection, cloud formation, and precipitation generation. To study the glacial-hydrologic dynamics over the Himalaya, a process-based glacial model (Crocus) is coupled with an advanced, fully distributed hydrologic model, WRF-Hydro. The coupled model, thus called the WRF-Hydro/Glacier, when combined with the WRF atmospheric model, offers the potential to accurately simulate the glacial and hydrologic processes in the world’s most complex topography