Work Package 4 - Modelling: application of climate models over HMA (Resp: M. Ménégoz – recruited at CNRS in 2019)
During the course of WATER-HIMAL, a couple of climate models will be used to interpret the meteorological conditions observed locally. The first one is the Modèle Atmosphérique Régional (MAR, CNRS, France), a regional climate model that has already been used to investigate precipitation variability in the Nepalese Himalaya17. This model will be applied to investigate precipitation variability over the last decades. The second one is the LMDZ, a GCM that is used to investigate the climate sensitivity to anthropogenic forcings6, in particular in the context of climate projections. The scientific questions approached with these tools is described below:
First, a high-resolution reanalysis will be produced over the Himalayas with the MAR model. The choice of a relatively small domain (2000 km2) centred over the Everest region in the central Himalaya will allow producing a large set of numerical experiments, offering the possibility to test different sets of reanalysis as boundary conditions, and in particular ERA-interim30, ERA5, ERA-20C and the Japanese ReAnalysis (JRA), and to tune the model for an accurate representation of precipitation. Finally, an atmospheric reanalysis will be produced over this region covering in a first step the last decades (ERA5 downscaling) and in a second step the whole 20th century (ERA-20C downscaling), with a resolution reaching 10 km, a significant step forward as compared to the existing ERA-Interim ( 80 km), ERA-5 ( 50 km), JRA reanalysis ( 55 km) and ERA20C ( 125 km). This high-resolution reanalysis will be used to: (i) investigate the climate inter-annual variability and trends over the last decades; (ii) extrapolate the local and recent observations over the previous decades, applying bias-correction methods to model outputs; (iii) highlight the links between large scale circulation patterns and local atmospheric conditions observed in the Everest region; (iv) quantify mass balance and glacier area change for the simulated period and region.

Updated on 8 April 2022