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From Climate Data to Adaptation Large-ensemble GCM Information and an Operational Policy-Support Model. Mark New Ana Lopez, Fai Fung, Milena Cuellar Funded by Tyndall and Environment Agency. Adaptation Challenges. Uncertainty in climate information Interactions with other uncertain changes
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From Climate Data to Adaptation Large-ensemble GCM Information and an Operational Policy-Support Model Mark New Ana Lopez, Fai Fung, Milena Cuellar Funded by Tyndall and Environment Agency
Adaptation Challenges • Uncertainty in climate information • Interactions with other uncertain changes • Integrated assessment
Route Map • Large ensemble climate data • River flow ensemble • Water resource system modelling
Large GCM Ensemble: CPdN • Explore model uncertainty by varying settings of poorly constrained model parameters • HADCM3L model: standard atmosphere & low resolution ocean. • 26 perturbed parameters (radiation, large scale cloud formation, ocean circulation, sulphate cycle, sea ice formation and energy convection) • Initial condition ensembles. • Transient runs: • 1920-2000 forced with historical CO2, solar and volcanic forcing. • 2000-2080 forced with different possible scenarios
IPCC 4AR models CPDN model runs First 246 Completed Simulations Global Mean Temperature: SRES A2 Anomaly from 1961-1990
Data Available • 10-year seasonal mean fields • Monthly mean (time series): • Large regions (Giorgi) • Selected grid-boxes (including UK) • Variables include • Total precipitation rate • Convective cloud amount • Surface air temperature (1.5m) • Relative humidity (1.5m)
Modelling Set-up • Downscale climate in space and time • SW England -> River Exe • Monthly -> Daily • Generate ensemble of daily river flows • CATCHMOD rainfall-runoff model • Run flow-ensemble through water resource model
August 1930-1985 August 2020-2060 Observed Observed Model Model Frequency Frequency Monthly Precip (mm/d) Monthly Precip (mm/d) Downscaling: Precipitation • Gamma transform method • Remove GCM monthly biases • Select daily values from observations
Downscaling: PET • Calculate GCM PET from • Temperature, RH & cloud-cover (radiation) • Adjust for climatological bias • No daily downscaling
River Flows Mean Flow Change: 2020-2039 from 1961-1990 % Change Month
Wimbleball Water Resource Model • Supplies: • Somerset & Devon (Exeter, Tiverton) • River & reservoir dominated • 50 ML/d Groundwater • Lancmod WR model
Wimbleball Reservoir: Historic Monthly Storage, 1930-2005 Storage (Ml x 104) Month
Wimbleball Reservoir: 2040 Ensemble Monthly Storage, 2040 Storage (Ml x 104) Month
Wimbleball Reservoir: Changing Risk September Storage Storage (Ml x 104) Year
Failure to Meet Demand Devon Demand Failure No. Simulations Year
Failure to Meet Demand Devon Demand Failure No. Simulations Ave. Shortfall Year
Outstanding Issues / Future Work • Biases in runoff simulations • Simplistic downscaling • Higher multiple year failures in simulations • Scenarios / ensembles of changing demand • Incorporating adaptation options • Staged methodology • Relative likelihoods • Comparison with UKCIP08 / ENSEMBLES