HR: 11:35h
AN: B22B-06 INVITED    [Abstracts]
TI: Large-scale evapotranspiration derived from MODIS GPP compared to MODIS evapotranspiration and 'observations'
AU: * Beer, C
EM: cbeer@bgc-jena.mpg.de
AF: Max Planck Institute for Biogeochemistry, Hans Knoell Str 10, Jena, 07745, Germany
AU: Reichstein, M
EM: mreichstein@bgc-jena.mpg.de
AF: Max Planck Institute for Biogeochemistry, Hans Knoell Str 10, Jena, 07745, Germany
AU: Chen, Y
EM: ychen@bgc-jena.mpg.de
AF: Max Planck Institute for Biogeochemistry, Hans Knoell Str 10, Jena, 07745, Germany
AU: Zhao, M
EM: zhao@ntsg.umt.edu
AF: College of Forestry & Conservation The University of Montana, 32 Campus Drive, Missoula, MT 59812, United States
AU: Mu, Q
EM: qiaozhen@ntsg.umt.edu
AF: College of Forestry & Conservation The University of Montana, 32 Campus Drive, Missoula, MT 59812, United States
AU: Running, S
EM: swr@ntsg.umt.edu
AF: College of Forestry & Conservation The University of Montana, 32 Campus Drive, Missoula, MT 59812, United States
AB: Coupling of carbon and water exchanges between leaf surface and surrounding air by stomatal conductance is well known for decades and led to the concept of water-use efficiency (WUE). It is the recent development of flux towers, however, which allows the estimation of the equivalent property at ecosystem scale. Here, we present global maps of WUE extrapolated from flux tower sites by using soil texture maps and remotely sensed leaf area index. Such spatial details of WUE are used for estimating gross primary production (GPP) from evapotranspiration (ET), or vice versa for estimating ET from remotely sensed GPP. The latter case will be presented in detail, and comparisons to ET directly derived from MODIS data and to ET approximated by precipitation, interception and runoff are shown. Interestingly, these (partly) independent approaches lead to similar results in some areas but discrepancies exist, too. Such analysis allows inferences about related uncertainties in each of the extrapolation approaches.
DE: 0428 Carbon cycling (4806)
DE: 0434 Data sets
DE: 0476 Plant ecology (1851)
DE: 0480 Remote sensing
DE: 1615 Biogeochemical cycles, processes, and modeling (0412, 0414, 0793, 4805, 4912)
SC: Biogeosciences [B]
MN: 2007 Fall Meeting