Assessment of Some Suggested Algorithms on Sea Colour and Surface Chlorophyll
The feasibility for converting intrinsic colour measurements of the sea into concentration of surface chlorophyll a, as well as into depths of the euphotic zone, is outlined.
This indirect determination of surface chlorophyll a concentration has a potential in oceanic areas because here the amount of yellow substance is small and only slightly variable in space and time. Moreover, the concentration of chlorophyll a and suspended matter are here interrelated.
In coastal waters, however, indirect determinations of chlorophyll a are performed with difficulty for two main reasons. Firstly, the amounts of yellow substance are often high and variable, especially at higher latitudes in the temperate climate. Secondly, chlorophyll a and yellow substance is only slightly correlated with suspended matter, especially if resuspension of bottom sediments is a dominant feature.
However, for a large variety of oceanic and coastal waters having different optical characteristics, colour measurements of the sea lead to satisfactory estimations of the depths of the euphotic zone.
KeywordsSuspended Matter Colour Index Euphotic Zone Secchi Disc Suggested Algorithm
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- Hovis, W.A., Clark, D.K., Anderson, F., Austin, R.W., Wilson, W.H., Baker, E.T., Ball, D., Gordon, H.R., Mueller, J.L., El Bayed, S.Y., Sturm, B., Wrigley, R.C. and Yentsch, C.S., 1980, “NIMBUS-7 Coastal Zone Color Scanner: System Description and Initial Imagery,” Science, 210, 60–63.CrossRefGoogle Scholar
- Hojerslev, N.K., 1977, “Spectral Daylight Irradiance and Light Transmittance in Natural Waters Measured by Means of a Secchi Disc only,” ICES, C, 42, 7 pp.Google Scholar
- Hojerslev, N. and Jerlov, N., 1977, “The Use of the Colour Index For Determining Quanta Irradiance in the Sea,” Rep. Inst. Phys. Oceanogr., Univ. Copenhagen, No. 35, 12 pp.Google Scholar
- Hojerslev, N.K., 1978, “Daylight Measurements Appropriate for Photosynthetic Studies in Natural Sea Water,” J. Cons. Int. Explor. Mer., 38 (2), 131–146.Google Scholar
- Hojerslev, N.K., 1980b, “On the Origin of Yellow Substance in the Marine Environment,” Rep. Inst. Phys. Oceanogr., Univ., Copenhagen, No. 42, 16 pp.Google Scholar
- Jerlov, N.G., 1977, “Classification of Seawaters in Terms of Quanta Irradiance,” J. Cons. Int. Explor. Mer., 37 (3), 281–287.Google Scholar
- Morel, A., 1980, “In-water and Remote Measurements of Ocean Color,” Bound. Layer Met., 177–201.Google Scholar
- Nordforsk., 1975, “Intercalibration of Methods For Determination of Chlorophyll a,” in Norwegian.Google Scholar