HR: 1340h
AN: H23D-1153    [Abstracts]
TI: Evaluation of MODIS Vegetation Products in Regions of Complex Terrain and Monsoon Climates
AU: * Gebremichael, M
EM: mek11@duke.edu
AF: Duke University, Box 90287, 121 Hudson Hall, Durham, NC 27708 United States
AU: Barros, A P
EM: ana.barros@duke.edu
AF: Duke University, Box 90287, 121 Hudson Hall, Durham, NC 27708 United States
AB: An evaluation of the Moderate Resolution Imaging Spectroradiometer (MODIS) vegetation products through comparison against independent surface observations is essential to establish quantitative measures of uncertainty and the confidence level of these satellite-based products for use in land-data assimilation models, for land-use change detection and attribution studies, and for process oriented research. Here, we focus specifically on Photosynthesis and Primary Productivity, Leaf Area Index (LAI) and Fraction of Photosynthetically Active Radiation (FPAR), Land Surface Temperature and Emissivity, and Evapotranspiration data sets. Our objective is to perform extensive quantitative assessment of the accuracy and statistical properties of these products against independent estimates in tropical mountainous regions at two climatologically distinct sites. The first site, the Sonora river basin in northern Mexico, is a semi-arid region characterized by complex topography and highly heterogeneous vegetation cover, which exhibits dramatic and fast response to rainfall forcing at the onset of the North-American Monsoon. The second site, the Marsyandi river basin in central Nepal, is a humid region characterized by strong ecohydrological gradients on steep orography, which remain generally stable subsequent to the onset of the Indian Monsoon. Atmospheric soundings, flux tower measurements, and raingauge observations are available for both sites. We evaluate the MODIS products in two ways: 1) comparison with tower-based observations, and 2) evaluation of hydrological response and diurnal cycles of surface water and energy budgets prior, during and post monsoon onset as simulated by a 3D hydroecological model with assimilation of MODIS data. Statistical analysis of the scaling behavior of the variables, both in space and time, is also performed to address the scale discrepancy between flux tower observations and the resolution of MODIS data.
DE: 3322 Land/atmosphere interactions
DE: 1818 Evapotranspiration
DE: 1878 Water/energy interactions
DE: 1615 Biogeochemical processes (4805)
DE: 1640 Remote sensing
SC: Hydrology [H]
MN: 2004 AGU Fall Meeting