WP 1 - Climatic boundary conditions and scenarios

WP1 will use the latest global climate change scenarios as boundary conditions to regional atmospheric models (RAMs) and simulate high resolution (25km) regional climate for the India and Himalaya region. The format of these simulations is designed to assess the inter-model uncertainty in GCM and RAM estimates of current and future temperature, evaporation and precipitation associated with monsoon climate regimes. The snowfall and temperatures will be used in WP2 to calculate the run-off from snow and glaciers.

The approach taken will be to use two RAM (PRECIS and REMO) driven by 6 hourly data from 3 sources.

1. Reanalysis data (ERA40)
2. The global climate model HadCM3.from MOHC
3. The global climate model ECHAM5 from MPI

The simulations using reanalysis data will produce the climate and variability most closely approaching 'truth'. However, the RAM physics will distort the 'truth' allowing an assessment of the model error. The global climate models simulate recent climate history as was a future predictions. The quality of the simulation of the past climate may be assessed against the simulations using the reanalysis data. This will allow an assessment of the ability of the climate models to produce observed climate and variability.

WP1 will benefit from large-scale regional climate scenarios generated in the WATCH project for the larger Indian region. WATCH will also provide methods to correct climate model biases and to transfer uncertainties from climate model data into hydrological models, which may be applied in HighNoon to the RAM simulations if considered appropriate.

Output, in the form of spatial and temporally varying climatic variables, from the RAM simulations will be provided to WP2.