HR: 10:50h
AN: H12A-03    [Abstracts]
TI: Further Test of the Hypothesis of Maximum Evaporation Using New Field Observations
AU: * Wang, J
EM: jfwang@mit.edu
AF: Massachusetts Institute of Technology, Room 48-336A, 15 Vassar Street,, Cambridge, MA 02139 United States
AU: Bras, R L
EM: rlbras@mit.edu
AF: Massachusetts Institute of Technology, Room 48-336A, 15 Vassar Street,, Cambridge, MA 02139 United States
AU: Eichinger, W
EM: william-eichinger@uiowa.edu
AF: The University of Iowa, IIHR Hydroscience & Engineering, 523B C. Maxwell Stanley Hydraulics Laboratory,, Iowa City, IA 52242 United States
AB: It was recently proposed (Wang et al, 2004, WRR) that there exists an extremum principle that governs the evaporation processes over land surfaces. The hypothesis of maximum evaporation was tested using observations of surface fluxes and surface temperature and soil moisture from earlier field experiments. To further test the theory, a new field experiment was conducted this Spring in Iowa for a more rigorous test of the hypothesis. Two observing towers were set up to measure turbulent fluxes of latent, sensible, and radiative fluxes with high sampling frequency. Soil heat flux and soil temperature at and below the land surface were measured using state-of-the-art devices. Soil moisture (volumetric water content and soil water potential) was also sampled with comparable temporal resolution, which is important for the hypothesis test. Continuous measurements over a period of two months have been obtained. The preliminary results, based on the new data, also support of the hypothesis of maximum evaporation.
DE: 1818 Evapotranspiration
DE: 1833 Hydroclimatology
DE: 1836 Hydrologic budget (1655)
DE: 1854 Precipitation (3354)
DE: 1866 Soil moisture
SC: Hydrology [H]
MN: 2004 AGU Fall Meeting