HR: 08:45h
AN: H31M-04    [Abstracts]
TI: Relocation of Southwestern US Terrestrial Moisture through Atmospheric Pathways
AU: * Dominguez, F
EM: francina@hwr.arizona.edu
AF: University of Arizona, SAHRA-Marshall Building 526B P.O. Box 210158B, Tucson, AZ 85721, United States
AU: Villegas, J C
EM: villegas@email.arizona.edu
AU: Breshears, D
EM: daveb@ag.arizona.edu
AB: Evapotranspiration accounts for the majority of the water budget in arid and semiarid regions such as the Southwestern U.S. Using a Lagrangian analytical model forced with North American Regional Reanalysis (NARR) data, we are able to identify the regions where this evapotranspired moisture is advected and eventually falls as precipitation. Our work shows that moisture originating from evapotranspiration in the Southwestern US contributes to precipitation throughout North America, particularly the Central Plains and the Midwestern US. Evapotranspiration and the subsequent export of moisture are particularly important during the North American monsoon season, when the combination of increased soil moisture, energy availability and atmospheric demand promotes the transference of water to the atmosphere via direct evaporation from the soil or transpiration by vegetation. Moisture evapotranspired in the four corners region of the Southwest contributes to an average 15% of the total summer precipitation in regions of Wyoming, Nebraska and Kansas. We find that during the 2000- 2003 drought period, the decrease in precipitation and evapotranspiration within the four corners region significantly decreased the amount of recycled precipitation of downwind regions. Due to the uncertainty in NARR evapotranspiration, observations and independent model outputs are used as validation. Our study illustrates the importance of moisture transport through atmospheric pathways, a process that links the surface hydrologic stores and atmospheric moisture fluxes.
DE: 1818 Evapotranspiration
DE: 1830 Groundwater/surface water interaction
DE: 1840 Hydrometeorology
DE: 1843 Land/atmosphere interactions (1218, 1631, 3322)
DE: 1878 Water/energy interactions (0495)
SC: Hydrology [H]
MN: 2007 Fall Meeting