Radiative transfer modelling of the relationship between seawater composition and remote sensing reflectance in sea lochs and fjords

A. Cunningham, P.I. Wood

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3 Citations (Scopus)


Sea lochs (small Scottish fjords) are Case 2 waters whose distinctive features include high surface gelbstoff concentrations, strong pycnoclines, high phytoplankton densities and low concentrations of non-biogenic particles. Measurements of the remote sensing reflectance spectra of these waters were made using a floating spectroradiometer during the spring diatom bloom in 1998. Calculations of radiative transfer were then carried out using the Hydrolight software package. The water column was modelled using gelbstoff and chlorophyll a profiles derived from in situ measurements of salinity and fluorescence, calibrated by the analysis of water bottle samples. Solar-stimulated chlorophyll fluorescence was described by a Gaussian peak centered on 685 nm with an apparent quantum yield of 1-2%. Appropriate levels of particle backscattering could be generated by incorporating a Henyey-Greenstein phase function in the model provided that the asymmetry parameter g was allowed to vary systematically with chlorophyll concentration. Since optical depths at 550 nm (the wavelength of maximum penetration) were in the range of 2-8 m for all stations the reflectance spectra were mainly determined by the inherent optical properties of reduced-salinity surface layers.
Original languageEnglish
Pages (from-to)3713-3724
Number of pages12
JournalInternational Journal of Remote Sensing
Issue number18
Publication statusPublished - 2002


  • sea lochs
  • Hydrolight software package
  • seawater
  • remote sensing reflectance
  • fjords

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