Remote Assessment of Ocean Color for Interpretation of Satellite Visible Imagery : A Review

About The ProductPublished by the American Geophysical Union as part of the __Lecture Notes on Coastal and Estuarine Studies Series__. This work is a contribution to the research encouraged by the IAPSO Working Group on Optical Oceanography, in particular its third term of reference ('Examination of ocean optical properties with their application to other aspects of oceanography, including physical oceanography, ocean dynamics, heat absorption and climatology, marine biology, and sedimentology.'). Due to the important amount of oceanographic data used in this study which have been acquired over a long period, all of the support received cannot be acknowledged. By restricting ourselves to the latest, we wish to acknowledge the Centre National de la Recherche Scientifique (under contracts ERA 278 and GRECO 034), the Centre National d'Etudes Spatiales (under contracts 80-81/250), the Centre National d'Exploitation des Oceans (under contracts 79/2084, 79/2010, and 81/203), the National Aeronautics and Space Administration (under contract NAS 5-22963 and grant NAGW-273), and the National Atmospheric and Oceanic Administration (under contract NA-7 9-SAC-00741). Content: Chapter 1 Front Matter (pages i–v): Chapter 1 Introduction (pages 1–2): Howard R. Gordon and Andre Y. MorelChapter 2 Physics of Ocean Color Remote Sensing (pages 3–23): Howard R. Gordon and Andre Y. MorelChapter 3 IN ? WATER ALGORITHMS (pages 24–67): Howard R. Gordon and Andre Y. MorelChapter 4 Atmospheric Correction (pages 68–71): Howard R. Gordon and Andre Y. MorelChapter 5 Application of The Algorithms to CZCS Imagery (pages 72–79): Howard R. Gordon and Andre Y. MorelChapter 6 Summary and Conclusions (pages 80–83): Howard R. Gordon and Andre Y. Morel Since the pioneering work of Clarke et a1. (1970) it has been known that chlorophyll a (or. more generally. pigments) contained in phytoplankton in near-surface waters produced systematic variations in the color of the ocean which could be observed from aircraft. As a direct result of this work. NASA developed the Coastal Zone Color Scanner (CZCS). which was launched on Nimbus-G (now Nimbus-7) in October 1978. (A short description of the CZCS is provided in Appendix I. ) Shortly before launch. at the IUCRM Colloquium on Passive Radiometry of the Ocean (June 1978). a working group on water color measurements was formed to assess water color remote sensing at that time. A report (Morel and Gordon. 1980) was prepared which summarized the state-of-the-art of the algorithms for atmospheric correction. and phytoplankton pigment and seston retrieval. and which included recommendations concerning the design of next generation sensors. The water color session of the COSPAR/SCOR/IUCRM Symposium 'Oceanography from Space' held in Venice (May 1980. i. e •• in the post-launch period) provided the opportunity for a reassessment of the state-of-the-art after having gained some experience in the analysis of the initial CZCS imagery. Such an assessment is the purpose of this review paper. which will begin with an outline of the basic physics of water color remote sensing and the fundamentals of atmospheric corrections. The present state of the constituent retrieval and atmospheric correction algorithms will then be critically assessed. Front Matter....Pages i-v Introduction....Pages 1-2 Physics of Ocean Color Remote Sensing....Pages 3-23 In — Water Algorithms....Pages 24-67 Atmospheric Correction....Pages 68-71 Application of the Algorithms to CZCS Imagery....Pages 72-79 Summary and Conclusions....Pages 80-83 Appendix I: The Coastal Zone Color Scanner (CZCS)....Pages 84-86 Appendix II: Recent Developments....Pages 87-102 References....Pages 103-114