Concentrations of Multiple Phytoplankton Pigments in the Global Oceans Obtained from Satellite Ocean Color Measurements with MERIS

Abstract

The remote sensing of chlorophyll a concentration from ocean color satellites has been an essential variable quantifying phytoplankton in the past decades, yet estimation of accessory pigments from ocean color remote sensing data has remained largely elusive. In this study, we validated the concentrations of multiple pigments (Cpigs) retrieved from in situ and MEdium Resolution Imaging Spectrometer (MERIS) measured remote sensing reflectance (Rrs(λ)) in the global oceans. A multi-pigment inversion model (MuPI) was used to semi-analytically retrieve Cpigs from Rrs(λ). With a set of globally optimized parameters, the accuracy of the retrievals obtained with MuPI is quite promising. Compared with High-Performance Liquid Chromatography (HPLC) measurements near Bermuda, the concentrations of chlorophyll a, b, c ([Chl-a], [Chl-b], [Chl-c]), photoprotective carotenoids ([PPC]), and photosynthetic carotenoids ([PSC]) can be retrieved from MERIS data with a mean unbiased absolute percentage difference of 38%, 78%, 65%, 36%, and 47%, respectively. The advantage of the MuPI approach is the simultaneous retrievals of [Chl-a] and the accessory pigments [Chl-b], [Chl-c], [PPC], [PSC] from MERIS Rrs(λ) based on a closure between the input and output Rrs(λ) spectra. These results can greatly expand scientific studies of ocean biology and biogeochemistry of the global oceans that are not possible when the only available information is [Chl-a].

Impact of Temporal Variation of Chlorophyll‐Specific Absorption on Phytoplankton Phenology Observed From Ocean Color Satellite: A Numerical Experiment

“…More importantly, we need to keep in mind that chlorophyll-a is just one of the many pigments contributing to a ph (λ). Thus, as proposed in Wang et al (2016Wang et al ( , 2018 and Chase et al (2017), a decomposition of a ph (λ) to the contributions of various pigments in R rs inversion is a viable step toward remotely sensing the concentration of chlorophyll from ocean color, although globally there are some average dependences between Chl and the accessory pigments (Trees et al, 2000).…”

Remote Sensing of Phytoplankton Pigments

“…As shown in Figure 1, in the Gaussian curve assumption in Hoepffner and Sathyendranath [29], each Gaussian curve represents the absorption curve of a specific pigment. C pigs are pigment concentrations, with a 0 and a i as empirical parameters [74].…”

Phytoplankton “Missing” Absorption in Marine Waters: A Novel Pigment Compensation Model for the Packaging Effect

“…In this study, four in situ measured data sets, 20 HPLC-derived phytoplankton pigments and a ph (λ) data (λ is the waveband from 400 nm to 700 nm), were collected in different oceans: (1) the marginal seas of China (Data set A), (2) the Atlantic Ocean (Data set B), (3) the South Atlantic Ocean (Data set C), and (4) the Pacific Ocean (Data set D). The concentrations of Chla, Chlb, Chlc, PPC, and PSC were estimated from HPLC measurements as (Bidigare et al, 1990;Ficek et al, 2004;Wang et al, 2018): (1) Chla = chlorophyll a + divinyl chlorophyll a + chlorophyllide a (2) Chlb = chlorophyll b (3) Chlc = chlorophylls c1c2 + chlorophyll c (4) PPC = diadinoxanthin + alloxanthin + zeaxanthin + β-carotene (5) PSC = fucoxanthin + 19'-hexanoyloxyfucoxanthin + 19'-butanoyloxyfucoxanthin + peridinin + prasinoxanthin Table 1 provides an overview of the different data sets, dates, locations, size, variables, TChla range, and the main usage. The peak information of the specific absorption coefficients in solvent of each group is shown in Table 2.…”