HR: 10:35h
AN: PP52A-02    [Abstracts]
TI: Anthropogenic-induced changes in the 21st Century summertime hydroclimatology of the Northeastern US
AU: * Anderson, B T
EM: brucea@bu.edu
AF: Department of Geography and Environment, Boston University, 675 Commonwealth Ave., Rm.457, Boston, MA 02215, United States
AB: Over the last 3 years, the Northeast Climate Impacts Assessment (NECIA) project has investigated the physical and socio-economic impacts upon the Northeastern US that may result from increased greenhouse gas emissions over the next century. In this presentation, changes in the summertime land/atmosphere hydroclimatology over the Northeastern US are investigated using a state-of-the-art regional climate modeling system. Results show that for the "business-as-usual" IPCC A1fi emissions scenario summertime precipitation is forecasted to increase over the northern and southern portions of the domain but decrease across the central portions; in contrast, evaporation is expected to increase across the entire domain. The balance between these two results in a decrease in summertime soil moisture content across most of the domain as well as an increase in the soil-moisture depletion rate that occurs during summer. At the same time, in the atmosphere there is an increase in both the specific and saturation specific humidity; the balance between these two results in an increase in relative humidity during the summer season. This increase in relative humidity, combined with an increase in overall temperatures, increases the daily maximum heat index for the region by 3.8C; for urban coastal regions the increase is even larger - up to 4.25C - resulting in an average heat index for the 5-month season that exceeds 32.2C (90F) - the level of "extreme caution" in today's climate. Finally, heavy-rainfall events are expected to increase across almost the entire domain, both with respect to frequency as well as intensity. In addition, the number of days which reach the "extreme caution" heat-index level are expected to increase by approximately 350% and could be reached every two out of three days in certain regions.
DE: 1637 Regional climate change
DE: 1807 Climate impacts
DE: 1833 Hydroclimatology
DE: 3305 Climate change and variability (1616, 1635, 3309, 4215, 4513)
SC: Paleoceanography and Paleoclimatology [PP]
MN: 2007 Fall Meeting