COP-10 In-Session Workshop, Buenos Aires, December 8, 20041

Application of Regional Application of Regional Models: High-Resolution Models: High-Resolution

Climate Change Scenarios Climate Change Scenarios for India Using PRECISfor India Using PRECIS

Rupa Kumar KolliRupa Kumar Kolli(kolli@tropmet.res.in)(kolli@tropmet.res.in)

Indian Institute of Tropical MeteorologyIndian Institute of Tropical Meteorology(http://www.tropmet.res.in)(http://www.tropmet.res.in)

Pune 411008, IndiaPune 411008, India

2COP-10 In-Session Workshop, Buenos Aires, December 8, 2004

Global models provide inadequate and even Global models provide inadequate and even inaccurate information on regional scales, inaccurate information on regional scales, more strikingly in the case of the Indian more strikingly in the case of the Indian summer monsoon variability patterns.summer monsoon variability patterns.

Summer Monsoon Rainfall (mm/day) Simulation by Summer Monsoon Rainfall (mm/day) Simulation by AOGCMsAOGCMsObservedObserved

3COP-10 In-Session Workshop, Buenos Aires, December 8, 2004

PRECIS ApplicationPRECIS Application PProviding roviding REREgional gional CClimates for limates for IImpacts mpacts SStudiestudies PRECIS runs on a Linux PC (horizontal resolutions PRECIS runs on a Linux PC (horizontal resolutions

currently available: 50 x 50 and 25 x 25 km).currently available: 50 x 50 and 25 x 25 km). Needs data for the selected domain on lateral boundary Needs data for the selected domain on lateral boundary

conditions (LBC) from the driving GCM (e.g., conditions (LBC) from the driving GCM (e.g., HadCM3/HadAM3) and the associated ancillary files HadCM3/HadAM3) and the associated ancillary files (e.g., sea surface temperatures, vegetation, topography, (e.g., sea surface temperatures, vegetation, topography, etc.).etc.).

Hadley Centre, UK has been providing PRECIS as well Hadley Centre, UK has been providing PRECIS as well as the driving data to several regional groups.as the driving data to several regional groups.

Baseline (1961-90), A2 and B2 scenarios (2071-2100). Baseline (1961-90), A2 and B2 scenarios (2071-2100). Reanalysis-driven runs provide comprehensive regional Reanalysis-driven runs provide comprehensive regional data sets representing current conditions, which can data sets representing current conditions, which can assist model evaluation as well as assessment of assist model evaluation as well as assessment of vulnerability to current climate variability.vulnerability to current climate variability.

Ensembles to estimate model-related uncertainties.Ensembles to estimate model-related uncertainties.

4COP-10 In-Session Workshop, Buenos Aires, December 8, 2004

GCMs to GCMs to Regional Regional Adaptive Adaptive Responses : Responses : Modelling Modelling PathPath

CCss = f(C = f(Cl l , Ø, Øss ) )

CCss - small scale - small scale climateclimateCCll - large scale - large scale climateclimateØØss - physiographic - physiographic details details at small at small scale scale

5COP-10 In-Session Workshop, Buenos Aires, December 8, 2004

Model OrographyModel Orography

Global ModelGlobal Model Regional Model Regional Model (PRECIS)(PRECIS)

6COP-10 In-Session Workshop, Buenos Aires, December 8, 2004

PRECIS captures important regional PRECIS captures important regional information on summer monsoon information on summer monsoon rainfall missing in its parent GCM rainfall missing in its parent GCM simulations.simulations.

7COP-10 In-Session Workshop, Buenos Aires, December 8, 2004

A2 Scenarios of seasonal precipitation A2 Scenarios of seasonal precipitation (% change), 2071-2100 based on (% change), 2071-2100 based on

PRECISPRECIS

8COP-10 In-Session Workshop, Buenos Aires, December 8, 2004

A2 Scenarios of seasonal surface A2 Scenarios of seasonal surface temperature (°C), 2071-2100, based temperature (°C), 2071-2100, based

on PRECISon PRECIS

9COP-10 In-Session Workshop, Buenos Aires, December 8, 2004

Applications in Impact Applications in Impact Assessment ModelsAssessment Models

PRECIS generates PRECIS generates comprehensive regional climate comprehensive regional climate information, physically information, physically consistent among all the consistent among all the variables.variables.

Can be directly plugged into Can be directly plugged into impact assessment modelsimpact assessment models

Used with water balance models Used with water balance models and river water routing and river water routing algorithms, PRECIS data enables algorithms, PRECIS data enables more realistic representation of more realistic representation of the processes affecting water the processes affecting water resources, even in smaller river resources, even in smaller river basins.basins.

PRECIS generates all the PRECIS generates all the required information to drive required information to drive crop-weather models, to crop-weather models, to estimate impacts on agriculture.estimate impacts on agriculture.

Regional vegetation models like Regional vegetation models like BIOME can be run with PRECIS BIOME can be run with PRECIS data to estimate changes in data to estimate changes in forest cover.forest cover.

10COP-10 In-Session Workshop, Buenos Aires, December 8, 2004

Data can be used to drive other Data can be used to drive other modelsmodels

A cyclone in the Bay of Bengal simulated by an RCM and the A cyclone in the Bay of Bengal simulated by an RCM and the resulting high water levels in the Bay simulated by a coastal resulting high water levels in the Bay simulated by a coastal

shelf model. shelf model.

11COP-10 In-Session Workshop, Buenos Aires, December 8, 2004

SummarySummary Application of the Hadley Centre’s regional climate model, Application of the Hadley Centre’s regional climate model,

PRECIS over the Indian region PRECIS over the Indian region Simulations of baseline for the current period (1961-90), A2 Simulations of baseline for the current period (1961-90), A2

(high emissions) and B2 (low emissions) scenarios for periods (high emissions) and B2 (low emissions) scenarios for periods up to 2100.up to 2100.

Scenarios used in India’s First National Communication to Scenarios used in India’s First National Communication to the UNFCCC.the UNFCCC.

Also used in climate change studies by the neighbouring Also used in climate change studies by the neighbouring South Asian nations.South Asian nations.

PRECIS demonstrated to be a powerful tool to build PRECIS demonstrated to be a powerful tool to build consistent regional climate change scenarios and determine consistent regional climate change scenarios and determine the sensitivity of the regional climate processes to natural the sensitivity of the regional climate processes to natural and anthropogenic forcings.and anthropogenic forcings.

Sensitivity studies to continue, and more scenarios to be Sensitivity studies to continue, and more scenarios to be built.built.

Multi-model ensembles (more RCMs, more driving GCMs) Multi-model ensembles (more RCMs, more driving GCMs) essential to obtain a better handle on the reliability of essential to obtain a better handle on the reliability of regional projections.regional projections.