HR: 1330h
AN: H22D-0955    [PDF]
TI: SATELLITE-BASED DAILY ACTUAL EVAPOTRANSPIRATION ESTIMATION
AU: * Guo, W
EM: Wei.Guo@noaa.gov
AF: Wei Guo, IMSG at NOAA/NESDIS NOAA Science Center 5200 Auth Rd., Rm 705, Camp Springs, MD 20746 United States
AU: Jiang, L
EM: jiangl@imsg.com
AF: Le Jiang, IMSG at NOAA/NESDIS NOAA Science Center 5200 Auth Rd., Rm 810, Station 8216, Camp Srpings, MD 20746 United States
AU: Islam, S
EM: Shafiqul.Islam@uc.edu
AF: Shafiqul Islam, Dept. of Civil & Environmental Engineering ML0071 Univ. of Cincinnati, Cincinnati, OH 45221 United States
AU: Senarath, S U
EM: ssenarat@sfwmd.gov
AF: Sharika U. S. Senarath, Hydrologic Systems Modeling Division Water Supply Department South Florida Water Management District, West Palm Beach, FL 33406 United States
AU: Ramsay, B H
EM: Bruce.H.Ramsay@noaa.gov
AF: Bruce H. Ramsay, Cooperative Institute for Climate Studies Earth System Science Interdisciplinary Center 2207 Computer and Space Sciences Building (#224), Room 4115F University of Maryland at College Park, College Park, MD 20742
AU: Eltahir, E A
EM: eltahir@mit.edu
AF: Elfatih A. B. Eltahir, Dept. of Civil & Environmental Engineering, MIT, Room 48-207, Cambridge, MA 02139
AB: Many water resources and agricultural applications require the knowledge of evapotranspiration (ET) over a range of spatial and temporal scales. Due to paucity of surface based hydro-meteorological stations, the spatial resolution of ET estimates is fairly coarse and is not particularly suitable or reliable for hydrologic modeling, water resources planning and decision making. We have developed an ET estimation algorithm by combining data from satellite and ground observations. Our proposed approach is simple, input data-adaptive, scalable, and end-user oriented with an evolution strategy. Our approach is based on an extension of the Priestley-Taylor equation and a relationship between remotely sensed surface temperature and vegetation index. The required parameters for this approach are derived from the Advanced High Resolution Radiometer aboard NOAA-14 over South Florida for 1998 and 1999. It first estimates the evaporative fraction (EF) by utilizing the relationship between NDVI and radiometric surface temperature observed from AVHRR for each day. Then spatio-temporal interpolation and filtering techniques were applied to obtain daily EF values for cloudy pixels to produce the EF map for the entire region. Daily ET (DAET) maps are derived from these EF maps and net radiation maps obtained from ground-based observations. The comparisons between satellite derived DAET and ground measured DAET showed overall low bias and root-mean-square-error for both clear and cloudy days in 1998 and 1999. The proposed DAET algorithm, primarily driven by satellite data and validated by multi-year real-time ground observations over the South Florida region, appears to be robust and can produce near real-time land surface evapotranspiration monitoring over large heterogeneous areas at a very fine space and time resolution.
DE: 1640 Remote sensing
DE: 1655 Water cycles (1836)
DE: 1818 Evapotranspiration
DE: 1878 Water/energy interactions
DE: 1890 Wetlands
SC: Hydrology [H]
MN: 2003 Fall Meeting