• Bio-optical properties of gelbstoff in the Arabian Sea at the onset of the southwest monsoon

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      https://www.ias.ac.in/article/fulltext/jess/109/04/0415-0425

    • Keywords

       

      Gelbstoff; chlorophyll; absorption; fluorescence; tryptophan-like

    • Abstract

       

      As part of the German JGOFS Indian Ocean Programme, a cruise occurred in the Arabian Sea in May 1997 at the onset of the southwest monsoon. Data on gelbstoff, chlorophylla and tryptophan-like fluorescence as well as gelbstoff absorption were obtained. They indicate, that these optical parameters support the interpretation of hydrographic and biogeochemical conditions. Tryptophan-like fluorescence seems to be a useful indicator of changes in the constitution of the biomass.

      A comparison of gelbstoff absorption and fluorescence data from the upper 100 m reveals only a weak covariance. Special emphasis is given to the fit procedure used for retrieving the exponential slopeS of the spectral absorption coefficient.S values with a mean of 0.016 nm-1 are found in the 350 to 480 nm wavelength range. A mean slopeS set to the frequently reported value of 0.014 nm-1 in the exponential description of gelbstoff absorption might lead to a systematic over/underestimation, and thus to systematic errors, if single-wavelength absorption values are extrapolated to other spectral regions on the basis of this parameter.

    • Author Affiliations

       

      Wiebke Breves1 Rainer Reuter1

      1. Fachbereich Physik, Carl von Ossietzky Universitat Oldenburg, Oldenburg - D-26111, Germany
    • Dates

       
  • Journal of Earth System Science | News

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