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Canada Water Accounts. AET estimates for typical land cover classes over point locations with sufficient long term records of climate data. Historical run based on observations 1960-2000 Projections based on 3 IPCC models x 3 IPCC scenarios
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Canada Water Accounts • AET estimates for typical land cover classes over point locations with sufficient long term records of climate data. • Historical run based on observations 1960-2000 • Projections based on 3 IPCC models x 3 IPCC scenarios • AET estimates for all sub-sub-basins in Canada. 1960-2000 • Historical run based on observations 1960-2000 • Projections based on 3 IPCC models x 3 IPCC scenarios • http://132.156.21.53:8080/reseau/servlet/LoadAll
Basic Definitions • Evapotranspiration ET –net water exchange between land or water surface and atmosphere. • Transpiration T – net water exchange from within vegetation. • Evaporation E= ET – T • Reference crop evapotranspiration (ETo) - ET from a hypothetical grass reference crop with specific characteristics no short of water. • “The use of other denominations such as potential ET is strongly discouraged due to ambiguities in their definitions. “http://www.fao.org/docrep/X0490E/x0490e04.htm#evaporation
EALCO Land Surface Model Wang S.,et al. 2002a, Climatic Change, 55: 451-477 Model initialization data 0.5 hourly meteo-forcings Input parameters (Remote sensing geospatial data) Model Output (0.5 hourly water balance components)
In-situ EO Input Canadian Weather Energy & Engineering Data Sets(CWEEDS) Hourly Rain, Snow, Insolation, Temp, Humidity, Pressure for 1960-2000. Mean Annual Precipitation (1961-1990) [mm/year] CWEEDS DATA GAPS (%hours missed) • Canadian Daily Climate Data (CDCD) stations: • Daily observations of • Total Precipitation and • Air Temperature
NCEP NARR, Precip., 85 March 10, 06:00 Gridded In-situ EO Climate Research Unit East Anglia Gridded Analysis Monthly 0.5 degree Rain, Snow, Insolation, Temp, Humidity, Pressure,wind for 1960-2000. NCAR Regional Reanalysis 2 3-Hourly 30km Rain, Snow, Insolation, Temp, Humidity, Pressure, wind for 1960-2000.
GCP Scenario Runs • 3 GCM Models run over 3 IPCC 4AR scenarios • Models: CGCM, Hadley, NCAR • Scenarios • SRESA1 – business as usual • SRES A2 – moderate mitigation; • SRES B1 - aggressive mitigation • Monthly difference fields observed to baseline datasets. No spatial downscaling. • Baseline year taken randomly from 5 “climatalogically” most similar years. • Some issues with suitability of scenario runs.
Historical Trends in ET at Points Slope of modelled annual ET relative to 1960-2000 Mean Modelled ET. Dominant land cover LAI soils. Mann-Kendall significance of modelled annual ET trends 1960-2000. Dominant land cover LAI soils.
Regional Historical Trends in ET Climate zone average of modelled annual AET anomalies. Dominant land cover LAI soils. Assumes input from precipitation only (no net inflow) Impact of CO2 on AET Trends