EVAPORATION AND EVAPOTRANSPIRATION UNDER CLIMATE-CHANGE IN NEW-ENGLAND

Methods to estimate and generate free-surface evaporation E(p) and potential evapotranspiration E(t) monthly time series are presented. Results are applied to the Quabbin and Wachusett water-supply reservoirs, which serve the Boston metropolitan area, and the Connecticut and Ware River basin watersheds, using historic (1950-80) climate data from several NOAA stations located in New England. The E(p) and E(t) time series are perturbed using climate-change scenarios of several general circulation models (GCMs) to investigate the sensitivity of both time series to doubled atmospheric CO2; E(p) and E(t) are also perturbed by +2 degrees C and +4 degrees C monthly temperature rises. The sensitivity of E(t) to a potential climate-change-induced vegetation-canopy resistance is also examined.