Reflectance data from MODIS, the Moderate Resolution Imaging Spectrometer onboard NASA's Earth Observing System (EOS) satellite Terra ( http://landval.gsfc.nasa.gov/MODIS/index.html ), is used to produce several science products including land cover, leaf area index (LAI), gross primary production (GPP) and net primary production (NPP). The overall goal of the BigFoot Project was to provide validation of these products.
Background information on the BigFoot Project is available at: http://www.fsl.orst.edu/larse/bigfoot/index.html.
A set of NPP/GPP summary figures was developed for each of the 9 BigFoot sites. Each set contains images and figures associated with creating the BigFoot NPP and GPP products, comparing them to MODIS products, and assessing the causes of differences. Related publications are Turner et al. 2003 and Turner et al. 2005.
Each summary file contains the following materials:
1. BigFoot land cover map. See Cohen et al. 2003a.
2. BigFoot LAI map. See Cohen et al. 2003a,b.
3. BigFoot LAI seasonal trajectory for dominant cover type. See Wythers et al. 2003.
4. Tower meteorological data.
5. BigFoot NPP map.
6. Comparison of BigFoot and flux tower daily GPP.
7. Comparison of MODIS and BigFoot daily GPP.
8. Comparison of MODIS and BigFoot NPP.
9. Comparison of MODIS and BigFoot GPP.
10. Comparison of NASA Data Assimilation Office and flux tower meteorological data.
11. Comparison of MODIS and BigFoot FPAR.
12. Comparison of MODIS and BigFoot LAI.
13. Comparison of MODIS and BigFoot light use efficiency.
Follow the links in this table to access the respective Site's Summary File.
Summary File Links
BOREAS NSA, Canada
Bondville, Illinois, USA
cropland (corn and soybean)
Harvard Forest LTER, Massachusetts, USA
temperate mixed forest
Konza Prairie LTER, Kansas, USA
Park Falls, Wisconsin, USA
temperate mixed forest
Cascades, Oregon, USA
temperate needleleaf forest
Sevilleta LTER, New Mexico, USA
tropical broadleaf evergreen forest
Barrow, AK, USA
arctic tundra site
For an in depth discussion of methods used to produce these summaries, please see the cited references.
Cite data summaries as follows:
Turner, D. P., W. D. Ritts, and M. Gregory. 2006. BigFoot GPP and NPP Summary, 2000-2004. Document. Available on-line from Oak Ridge National Laboratory Distributed Active Archive Center, Oak Ridge, Tennessee, U.S.A.
Cohen, W.B., Maiersperger, T.K., Yang, Z., Gower, S.T., Turner, D.P., Ritts, W.D., Berterretche, M., Running, S.W. 2003a. Comparisons of land cover and LAI estimates derived from ETM+ and MODIS for four sites in North America: a quality assessment of 2000/2001 provisional MODIS products. Remote Sensing of Environment 88:233-255.
Cohen , W.B., T.K. Maiersperger, S.T. Gower, and D.P. Turner. 2003b. An improved strategy for regression of biophysical variables and Landsat ETM+ data, Remote Sensing of Environment 84:561-571.
Turner, D.P., Ritts, W.D., Cohen, W.B., Gower, S.T., Zhao, M., Running, S.W., Wofsy, S.C., Urbanski, S., Dunn, A., Munger, J.W. 2003. Scaling gross primary production (GPP) over boreal and deciduous forest landscapes in support of MODIS GPP product validation. Remote Sensing of Environment 88:256-270.
Turner, D.P., Ritts, W.D., Cohen, W.B., Maeirsperger, T.K., Gower, S.T., Kirschbaum, A., Running, S.W., Zhao, M., Wofsy, S.C., Dunn, A.L., Law, B.E., Campbell, J.C., Oechel, W.C., Kwon, H.J., Meyers, T.P., Small, E.E., Kurc, S.A., Gamon, J.A. 2005. Site-level evaluation of satellite-based global terrestrial gross primary production and net primary production monitoring. Global Change Biology 11:666-684.
Wythers, K.R., Reich, P.B., Turner, D.P. 2003. Predicting leaf area index from scaling principles: corroboration and consequences. Tree Physiology 23:1171-1179.
Wythers, K. R., P. B. Reich, M. G. Tjoelker, and P. B. Bolstad. 2005. Foliar respiration acclimation to temperature and temperature variable Q(10) alter ecosystem carbon balance. Global Change Biology 11(3): 435-449.