COP-10 In-Session Workshop, Buenos Aires, December 8, Application of Regional Models: High-Resolution Climate Change Scenarios for India Using PRECIS Rupa Kumar Kolli Indian Institute of Tropical Meteorology ( Pune , India

2 COP-10 In-Session Workshop, Buenos Aires, December 8, 2004 Global models provide inadequate and even inaccurate information on regional scales, more strikingly in the case of the Indian summer monsoon variability patterns. Summer Monsoon Rainfall (mm/day) Simulation by AOGCMs Observed

3 COP-10 In-Session Workshop, Buenos Aires, December 8, 2004 PRECIS Application Providing REgional Climates for Impacts Studies Providing REgional Climates for Impacts Studies PRECIS runs on a Linux PC (horizontal resolutions currently available: 50 x 50 and 25 x 25 km). PRECIS runs on a Linux PC (horizontal resolutions currently available: 50 x 50 and 25 x 25 km). Needs data for the selected domain on lateral boundary conditions (LBC) from the driving GCM (e.g., HadCM3/HadAM3) and the associated ancillary files (e.g., sea surface temperatures, vegetation, topography, etc.). Needs data for the selected domain on lateral boundary conditions (LBC) from the driving GCM (e.g., HadCM3/HadAM3) and the associated ancillary files (e.g., sea surface temperatures, vegetation, topography, etc.). Hadley Centre, UK has been providing PRECIS as well as the driving data to several regional groups. Hadley Centre, UK has been providing PRECIS as well as the driving data to several regional groups. Baseline ( ), A2 and B2 scenarios ( ). Reanalysis- driven runs provide comprehensive regional data sets representing current conditions, which can assist model evaluation as well as assessment of vulnerability to current climate variability. Baseline ( ), A2 and B2 scenarios ( ). Reanalysis- driven runs provide comprehensive regional data sets representing current conditions, which can assist model evaluation as well as assessment of vulnerability to current climate variability. Ensembles to estimate model-related uncertainties. Ensembles to estimate model-related uncertainties.

4 COP-10 In-Session Workshop, Buenos Aires, December 8, 2004 GCMs to Regional Adaptive Responses : Modelling Path C s = f(C l, Ø s ) C s - small scale climate C l - large scale climate Ø s - physiographic details at small scale

5 COP-10 In-Session Workshop, Buenos Aires, December 8, 2004 Model Orography Global Model Regional Model (PRECIS)

6 COP-10 In-Session Workshop, Buenos Aires, December 8, 2004 PRECIS captures important regional information on summer monsoon rainfall missing in its parent GCM simulations.

7 COP-10 In-Session Workshop, Buenos Aires, December 8, 2004 A2 Scenarios of seasonal precipitation (% change), based on PRECIS

8 COP-10 In-Session Workshop, Buenos Aires, December 8, 2004 A2 Scenarios of seasonal surface temperature (°C), , based on PRECIS

9 COP-10 In-Session Workshop, Buenos Aires, December 8, 2004 Applications in Impact Assessment Models PRECIS generates comprehensive regional climate information, physically consistent among all the variables. PRECIS generates comprehensive regional climate information, physically consistent among all the variables. Can be directly plugged into impact assessment models Can be directly plugged into impact assessment models Used with water balance models and river water routing algorithms, PRECIS data enables more realistic representation of the processes affecting water resources, even in smaller river basins. Used with water balance models and river water routing algorithms, PRECIS data enables more realistic representation of the processes affecting water resources, even in smaller river basins. PRECIS generates all the required information to drive crop-weather models, to estimate impacts on agriculture. PRECIS generates all the required information to drive crop-weather models, to estimate impacts on agriculture. Regional vegetation models like BIOME can be run with PRECIS data to estimate changes in forest cover. Regional vegetation models like BIOME can be run with PRECIS data to estimate changes in forest cover.

10 COP-10 In-Session Workshop, Buenos Aires, December 8, 2004 Data can be used to drive other models A cyclone in the Bay of Bengal simulated by an RCM and the resulting high water levels in the Bay simulated by a coastal shelf model.

11 COP-10 In-Session Workshop, Buenos Aires, December 8, 2004 Summary Application of the Hadley Centre’s regional climate model, PRECIS over the Indian region Application of the Hadley Centre’s regional climate model, PRECIS over the Indian region Simulations of baseline for the current period ( ), A2 (high emissions) and B2 (low emissions) scenarios for periods up to Simulations of baseline for the current period ( ), A2 (high emissions) and B2 (low emissions) scenarios for periods up to Scenarios used in India’s First National Communication to the UNFCCC. Scenarios used in India’s First National Communication to the UNFCCC. Also used in climate change studies by the neighbouring South Asian nations. Also used in climate change studies by the neighbouring South Asian nations. PRECIS demonstrated to be a powerful tool to build consistent regional climate change scenarios and determine the sensitivity of the regional climate processes to natural and anthropogenic forcings. PRECIS demonstrated to be a powerful tool to build consistent regional climate change scenarios and determine the sensitivity of the regional climate processes to natural and anthropogenic forcings. Sensitivity studies to continue, and more scenarios to be built. Sensitivity studies to continue, and more scenarios to be built. Multi-model ensembles (more RCMs, more driving GCMs) essential to obtain a better handle on the reliability of regional projections. Multi-model ensembles (more RCMs, more driving GCMs) essential to obtain a better handle on the reliability of regional projections.