Inversion of in situ light absorption and attenuation measurements to estimate constituent concentrations in optically complex shelf seas

M. Ramírez-Pérez, M. Twardowski, C. Trees, J. Piera, D. McKee

Research output: Contribution to journalArticle

Abstract

A deconvolution approach is presented to use spectral light absorption and attenuation data to estimate the concentration of the major non-water compounds in complex shelf sea waters. The inversion procedure requires knowledge of local material-specific inherent optical properties (SIOPs) which are determined from natural samples using a bio-optical model that differentiates between Case I and Case II waters and uses least squares linear regression analysis to provide optimal SIOP values. A synthetic data set is used to demonstrate that the approach is fundamentally consistent and to test the sensitivity to injection of controlled levels of artificial noise into the input data. Self-consistency of the approach is further demonstrated by application to field data collected in the Ligurian Sea, with chlorophyll (Chl), the nonbiogenic component of total suspended solids (TSSnd) and colored dissolved organic materials (CDOM) retrieved with RMSE of 0.61 mg m-3, 0.35 g m-3 and 0.02 m-1 respectively. The utility of the approach is finally demonstrated by application to depth profiles of in situ absorption and attenuation data resulting in profiles of optically significant constituents with associated error bar estimates. The advantages of this procedure lie in the simple input requirements, the avoidance of error amplification, full exploitation of the available spectral information from both absorption and attenuation channels, and the reasonably successful retrieval of constituent concentrations in an optically complex shelf sea.
LanguageEnglish
Pages720-737
Number of pages18
JournalJournal of Geophysical Research: Oceans
Volume123
Issue number1
Early online date9 Jan 2018
DOIs
StatePublished - 31 Jan 2018

Fingerprint

shelf sea
electromagnetic absorption
shelves
Light absorption
Optical properties
attenuation
optical properties
inversions
Water
Chlorophyll
Deconvolution
estimates
Linear regression
Regression analysis
optical property
Amplification
total suspended solids
sea water
avoidance
chlorophylls

Keywords

  • inherent optical properties
  • material-specific IOPs
  • spectral deconvolution model
  • Ligurian Sea

Cite this

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title = "Inversion of in situ light absorption and attenuation measurements to estimate constituent concentrations in optically complex shelf seas",
abstract = "A deconvolution approach is presented to use spectral light absorption and attenuation data to estimate the concentration of the major non-water compounds in complex shelf sea waters. The inversion procedure requires knowledge of local material-specific inherent optical properties (SIOPs) which are determined from natural samples using a bio-optical model that differentiates between Case I and Case II waters and uses least squares linear regression analysis to provide optimal SIOP values. A synthetic data set is used to demonstrate that the approach is fundamentally consistent and to test the sensitivity to injection of controlled levels of artificial noise into the input data. Self-consistency of the approach is further demonstrated by application to field data collected in the Ligurian Sea, with chlorophyll (Chl), the nonbiogenic component of total suspended solids (TSSnd) and colored dissolved organic materials (CDOM) retrieved with RMSE of 0.61 mg m-3, 0.35 g m-3 and 0.02 m-1 respectively. The utility of the approach is finally demonstrated by application to depth profiles of in situ absorption and attenuation data resulting in profiles of optically significant constituents with associated error bar estimates. The advantages of this procedure lie in the simple input requirements, the avoidance of error amplification, full exploitation of the available spectral information from both absorption and attenuation channels, and the reasonably successful retrieval of constituent concentrations in an optically complex shelf sea.",
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Inversion of in situ light absorption and attenuation measurements to estimate constituent concentrations in optically complex shelf seas. / Ramírez-Pérez, M.; Twardowski, M.; Trees, C.; Piera, J.; McKee, D.

In: Journal of Geophysical Research: Oceans, Vol. 123, No. 1, 31.01.2018, p. 720-737.

Research output: Contribution to journalArticle

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