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Absorbed Photosynthetically Active Radiation (FAPAR), sometimes also called fAPAR or fPAR, is a radiation measure which indicates the presence of vegetation and reflects its photosynthetic activity. Spatially-detailed descriptions of FAPAR provide information about the relative strength and location of terrestrial carbon pools and fluxes. It is one of the surface parameters that may be used in quantifying the CO2 assimilation by plants and the release of water through evapotranspiration.

ECV fAPAR standards report

As requested by UNFCCC SBSTA/COP for its 23rd Session in Montreal, November 2005, GTOS is undertaking the assessment of the status of the development of standards for each of the essential climate variables in the terrestrial domain. The following report, documentation and other material have been compiled for fAPAR. We very much welcome your comments and inputs in improving and completing the analysis for fAPAR. Please send any material and comments to the GTOS Secretariat.


Download report PDF, 1.00 Mb, 1 November 2009


Listed below are the major references that have been identified in regards to methodology and standards for fAPAR. Please inform us if you are aware of any other documentation or material which could be considered.

Chen, J. M., and J. Cihlar. 1999. BOREAS RSS-07 Regional LAI and FPAR Images From Ten-Day AVHRR-LAC Composites. Data set. Available on-line [http://www.daac.ornl.gov] from Oak Ridge National Laboratory Distributed Active Archive Center, Oak Ridge, Tennessee, U.S.A.

Fensholt, R., Sandholt, I., and Rasmussen, M.S. 2004. Evaluation of MODIS LAI, fAPAR and the relation between fAPAR and NDVI in a semi-arid environment using in situ measurements. Remote Sensing of Environment 91: 490-507.

Garrigues, S., Morisette, J., Nickeson, J., Lacaze, R., Fernandes, R., Yang, W., Myneni, R., Baret, F., Weiss, M., and Plummer, S. 2006. Leaf Area Index inter-comparison and validation as a prototype activity for WGCV/LPV. Presented at the WGCV Plenary, 9-12 May, Budapest, Hungary. See document

Gobron, N., Pinty, B., Aussedat, O., Chen, J., Cohen, W. B., Fensholt, R., Gond, V., Hummerich, K. F., Lavergne, T., Melin, F., Privette, J. L., Sandholt, I., Taberner, M., Turner, D. P., Verstraete, M. M. and Widlowski, J.-L. 2006. Evaluation of FAPAR products for different canopy radiation transfer regimes: Methodology and results using JRC products derived from SeaWiFS against ground-based estimations. Journal of Geophysical Research 111 (D13110), doi: 10.1029/2005JD006511.

Leblanc, S.G., Chen, J.M., Fernandes, R., Deering, D.W., and Conley, A. 2005. Methodology comparison for canopy structure parameters extraction from digital hemispherical photography in boreal forests. Agricultural and Forest Meteorology 129: 187–207.

Margolis, H. 1997. Relationship between FPAR and leaf nitrogen for black spruce, jack pine and aspen stands at the BOREAS Northern Study Area. See document

Myneni, R. B., Nemani, R. R., and Running, S. W. 1997. Algorithm for the estimation of global land cover, LAI and FPAR based on radiative transfer models. IEEE Transactions on Geoscience and Remote Sensing 35: 1380– 1393.

Rahman, H., Verstraete, M., and Pinty, B. 1993. Coupled surface-atmosphere reflectance (CSAR) model. 1: Model description and inversion on synthetic data . Journal of Geophysical Research 98, (D11): 20,779-20,789.

Tian, Y., Dickinson, R. E., Zhou, L., Zeng, X., Dai, Y., Myneni, R. B., Knyazikhin, Y., Zhang, X., Friedl, M., Yu, H., Wu, W., and Shaikh, M. 2004. Comparison of seasonal and spatial variations of leaf area index and fraction of absorbed photosynthetically active radiation from Moderate Resolution Imaging Spectroradiometer (MODIS) and Common Land. Journal of Geophysical Research 109 (D01103), doi:10.1029/2003JD003777.

Morisette, J. 2006. CEOS Land Product Subgroup Report. Presented at the WGCV Plenary, 9-12 May, Budapest, Hungary. See document

TOPC. 2004. Terrestrial Observation Panel for Climate Report to WGCV 22. 22nd Meeting of the Working Group on Calibration and Validation, 15th June, Sioux Falls, SD. See document.

Yang, W., Huang, D., Tan, B., Stroeve, J. C., Shabanov, N. V., Knyazikhin, Y., Nemani, R. R., and Myneni, R. B.. 2006. Analysis of leaf area index and fraction vegetation absorbed PAR products from the Terra MODIS sensor: 2000–2004. IEEE Transactions for Geoscience and Remote Sensing 44: 1829–1842.

WMO. 2006. Guide to Meteorological Instruments and Methods of Observation. Preliminary seventh edition. Report WMO-No. 8, Geneva, Switzerland.

Relevant Web links

Relevant fAPAP Web sites will be listed here. Your contributions are welcome.

TEMS variables and T-sites

The Terrestrial Ecosystem Monitoring Sites (TEMS) database contains details on ecological variables and research sites which are undertaking ecological measurements.


We would like to thank the following individuals for having provided inputs and comments to the fAPAR ECV.

. Josef Cihlar


We welcome your inputs, comments and queries. Please send feedback to the GTOS Secretariat.

The above activities are part of Task Number CL-06-03 of the GEOSS implementation plan of GEO.

T1-River | T2-Water Use  | T3-Ground Water | T4-Lake | T5-Snow | T6-Galciers |
T7-Frost | T8-Albedo | T9-Land | T10-fAPAR | T11-LAI | T12-Biomass | T13-Fire |
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© FAO   ::   Global Terrestrial Observing System - GTOS   ::   11 November 2009