Photosynthetically Active Radiation (PAR)
as Observed from Satellites

Department of Atmospheric and Oceanic Science
University of Maryland, College Park

Department of Atmospheric and Oceanic Science



Satellite Data

Available PAR Parameters


Data Distribution

Data Access





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Improved the ability to observe, understand, and predict climate and its response to changes in global environment, is an objective of the National Oceanic and Atmospheric Administration (NOAA) Climate and Global Change Program and several NASA research programs. Information on Photosynthetically Active Radiation (PAR) is needed to address several climate issues. An activity to derive PAR from satellite observations was undertaken at the University of Maryland. Capabilities were developed to derive PAR on regional and global scale; to generate climatology of this parameter; to learn about its spatial and temporal variability; to evaluate the satellite estimates against ground truth; to quantify the relationship between PAR and total shortwave radiation; and to make this information available to the scientific community.



This activity was initially supported by the NOAA Climate and Global Change Program/Climate Observations, Office of Global Programs, United States Department of Commerse, National Oceanic and Atmospheric Administration, W. Murray, Program Manager, and continues under support from the NASA Earth Science and Application Division, Climate Research, and the Mission to Planet Earth Programs, under the direction of Drs.  R. A. Schiffer and  J. Dodge. The ISCCP data used were obtained from the NASA Langley Research Center EOSDIS Distributed Active Archive Center.

Maintained by Banglin Zhang and Chuan Li