WP1 Climate modelling
WP Lead: Dr. Jan Erik Haugen (met.no), contribution from NVE

Objective: To detect feedback mechanisms from glacier ice mass balance and geometry to the atmosphere in Indian catchments in the Himalaya region, and establish one projection for land surface hydrology including snow, glaciers, subsurface water and streamflow.

A parameterisation procedure for glacier ice mass balance and glacier geometry to be used in regional climate models (RCMs) will be developed. The method will apply a simplified mass balance and ice flow model that modifies the glacier covered area and ice volume for elevation bands based on the driving meteorological variables. This method is based on a one-dimensional continuity equation for ice flow, a flux law using the local ice surface gradient and the mass balance for each elevation band, following the approach of Guðmundsson et al. (2009). The method will be developed and tested with the spatially distributed version of the HBV hydrological model (Beldring et al., 2003) and the land surface scheme of WRF (Noah) using available observed hydrological and glacier mass balance data as well as available data provided from WP3 for verification. Noah has participated in numerous international modeling projects in which evaluation of its performance has subsequently led to improved parameterisations, e.g. the Torne Kalix experiment (Northern Sweden; Bowling et al. (2003)) and the Rhone-AGG (France) experiment (Boone et al., 2004). Interactions between the land surface and the atmosphere in both models are based on precipitation, temperature, radiation, humidity, wind speed and air pressure. The hydrological model applies energy balance equations for snow and ice melt and a combination of energy balance and mass transfer for latent and sensible heat fluxes. The procedure will then be run within WRF to provide a dynamically evolving interface between the atmosphere and the land surface. Assessment of the impact of climate change on future hydrological processes including river flow will use this parameterisation procedure.

The Bjerknes centre for climate research are using the WRF model to provide RCM runs in the region, and will provide available projections by the end of 2012 (pers. com. E. Janson, 2011). The RCM run will have to be post-processed based on frequency distribution of meteorological data provided from the ERAINT dataset to be applicable for hydrological modelling. The performance of ERAINT will be evaluated in conjunction with WP2. The hydrological HBV model will be parameterised and run with the post processed projection to obtain the hydrological projection. The hydrological projection will be available for analysis in WP2. The parameterisation procedure for glacier ice mass balance and glacier geometry will then be developed based on sensitivity study of the land surface model Noah and the RCM (WRF).

Deliverables:1) Scientific report with assessment of the impact of climate change on water resources in glacier covered catchments in India. 2) Scientific report with assessment of feedback mechanism from snow and ice covered catchments in Himalaya to the atmosphere. 3) Scientific paper describing dynamical glacier ice volume and glacier area modelled in a hydrological model and one land surface scheme of an atmospheric model, and the feedback mechanism from snow and ice covered catchments in western Himalaya to the atmosphere.