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A two‐component description of spectral absorption by marine particles
Author(s) -
Morrow J. H.,
Chamberlin W. S.,
Kiefer D. A.
Publication year - 1989
Publication title -
limnology and oceanography
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.7
H-Index - 197
eISSN - 1939-5590
pISSN - 0024-3590
DOI - 10.4319/lo.1989.34.8.1500
Subject(s) - detritus , phytoplankton , absorption (acoustics) , water column , attenuation coefficient , absorption spectroscopy , wavelength , spectral line , atmospheric sciences , analytical chemistry (journal) , chemistry , oceanography , environmental chemistry , geology , physics , optics , biology , ecology , nutrient , astronomy , organic chemistry
Values for the spectral absorption coefficient of particles sampled in the Sargasso Sea (34°N, 70°W) in 1987 were subjected to a multiple regression analysis to assess contributions to light absorption by phytoplankton and detritus. Specifically, values for the spectral absorption coefficient at a given wavelength were treated as a function of the values for absorption at 675 and 570 nm. The spectrum for slopes for the 675‐nm component has a slope like that of phytoplankton, and the slopes for the 570‐nm component resemble that of detritus. Individual spectra were then partitioned into phytoplankton and detrital spectral absorption coefficients with an algorithm that minimized the difference between the original spectrum and sum of the two components. The two‐component model accounted for >90% of the observed spectral absorption coefficients for all samples collected within the upper 300 m of the water column. Profiles of the two components indicated that there was little variation in mean absorption coefficient for detritus with depth. In contrast, the greatest variability was accounted for by changes in the phytoplankton component, both with depth and seasonally during 1987. This seasonal variation is interpreted in terms of photoadaptation by cells to changes in the light and vertical mixing fields.