Using MODIS-Derived Vegetation Indices to Infer Ecosystem Productivity

Karl Fred Huemmrich, NASA GSFC/UMBC, karl.f.huemmrich@nasa.gov (Presenter)
David Landis, GST, david.r.landis@nasa.gov
John Gamon, University of Alberta, gamon@ualberta.ca
Elizabeth M. Middleton, NASA GSFC, elizabeth.m.middleton@nasa.gov

The Normalized Difference Vegetation Index (NDVI) can provide a good metric of photosynthetic phenology and productivity (Gross Primary Production (GPP)) under some conditions (e.g. annuals and deciduous vegetation during green-up), but not others (e.g. mid-summer periods or in evergreens). Where the controls on ecosystem production are poorly defined by NDVI, seasonal and day to day shifts in pigment pool sizes (e.g. chlorophyll:carotenoid ratios) provide indicators of photosynthetic activity and downregulation. The Photochemical Reflectance Index (PRI), which is sensitive to seasonal and diurnal pigment pool shifts has been shown to provide a useful metric of light use efficiency and GPP. Several studies using combinations of MODIS land and ocean bands have shown that a MODIS PRI can capture useful information on photosynthetic activity or GPP, but the ocean bands have not been routinely available in the past, so only limited studies using this index from MODIS have been done. The Collection 6 reprocessing of MODIS surface reflectance products is producing surface reflectances for the ocean bands over land, providing an opportunity to explore new vegetation indices and their performance for a variety of sites over multiple years. Relationships between MODIS-based indices and GPP from multiple different flux tower sites will be shown.

Presentation Type:  Poster

Session:  Theme 3: Future research direction and priorities: perspectives relevant to the next decadal survey   (Mon 4:30 PM)

Associated Project(s): 

• Middleton, Betsy: Spectral Bio-Indicators of Ecosystem Photosynthetic Efficiency II: Synthesis and Integration ...details

Poster Location ID: 201