Regional ocean-colour chlorophyll algorithms for the Red Sea

Handle URI:
http://hdl.handle.net/10754/574977
Title:
Regional ocean-colour chlorophyll algorithms for the Red Sea
Authors:
Brewin, Robert J.W.; Raitsos, Dionysios E.; Dall'Olmo, Giorgio; Zarokanellos, Nikolaos; Jackson, Thomas; Racault, Marie-Fanny; Boss, Emmanuel S.; Sathyendranath, Shubha; Jones, Burton ( 0000-0002-9599-1593 ) ; Hoteit, Ibrahim ( 0000-0002-3751-4393 )
Abstract:
The Red Sea is a semi-enclosed tropical marine ecosystem that stretches from the Gulf of Suez and Gulf of Aqaba in the north, to the Gulf of Aden in the south. Despite its ecological and economic importance, its biological environment is relatively unexplored. Satellite ocean-colour estimates of chlorophyll concentration (an index of phytoplankton biomass) offer an observational platform to monitor the health of the Red Sea. However, little is known about the optical properties of the region. In this paper, we investigate the optical properties of the Red Sea in the context of satellite ocean-colour estimates of chlorophyll concentration. Making use of a new merged ocean-colour product, from the European Space Agency (ESA) Climate Change Initiative, and in situ data in the region, we test the performance of a series of ocean-colour chlorophyll algorithms. We find that standard algorithms systematically overestimate chlorophyll when compared with the in situ data. To investigate this bias we develop an ocean-colour model for the Red Sea, parameterised to data collected during the Tara Oceans expedition, that estimates remote-sensing reflectance as a function of chlorophyll concentration. We used the Red Sea model to tune the standard chlorophyll algorithms and the overestimation in chlorophyll originally observed was corrected. Results suggest that the overestimation was likely due to an excess of CDOM absorption per unit chlorophyll in the Red Sea when compared with average global conditions. However, we recognise that additional information is required to test the influence of other potential sources of the overestimation, such as aeolian dust, and we discuss uncertainties in the datasets used. We present a series of regional chlorophyll algorithms for the Red Sea, designed for a suite of ocean-colour sensors, that may be used for further testing.
KAUST Department:
Red Sea Research Center (RSRC); Earth Science and Engineering Program
Citation:
Regional ocean-colour chlorophyll algorithms for the Red Sea 2015, 165:64 Remote Sensing of Environment
Publisher:
Elsevier BV
Journal:
Remote Sensing of Environment
Issue Date:
18-May-2015
DOI:
10.1016/j.rse.2015.04.024
Type:
Article
ISSN:
00344257
Additional Links:
http://linkinghub.elsevier.com/retrieve/pii/S0034425715001662
Appears in Collections:
Articles; Red Sea Research Center (RSRC); Earth Science and Engineering Program

Full metadata record

DC FieldValue Language
dc.contributor.authorBrewin, Robert J.W.en
dc.contributor.authorRaitsos, Dionysios E.en
dc.contributor.authorDall'Olmo, Giorgioen
dc.contributor.authorZarokanellos, Nikolaosen
dc.contributor.authorJackson, Thomasen
dc.contributor.authorRacault, Marie-Fannyen
dc.contributor.authorBoss, Emmanuel S.en
dc.contributor.authorSathyendranath, Shubhaen
dc.contributor.authorJones, Burtonen
dc.contributor.authorHoteit, Ibrahimen
dc.date.accessioned2015-08-18T08:25:59Zen
dc.date.available2015-08-18T08:25:59Zen
dc.date.issued2015-05-18en
dc.identifier.citationRegional ocean-colour chlorophyll algorithms for the Red Sea 2015, 165:64 Remote Sensing of Environmenten
dc.identifier.issn00344257en
dc.identifier.doi10.1016/j.rse.2015.04.024en
dc.identifier.urihttp://hdl.handle.net/10754/574977en
dc.description.abstractThe Red Sea is a semi-enclosed tropical marine ecosystem that stretches from the Gulf of Suez and Gulf of Aqaba in the north, to the Gulf of Aden in the south. Despite its ecological and economic importance, its biological environment is relatively unexplored. Satellite ocean-colour estimates of chlorophyll concentration (an index of phytoplankton biomass) offer an observational platform to monitor the health of the Red Sea. However, little is known about the optical properties of the region. In this paper, we investigate the optical properties of the Red Sea in the context of satellite ocean-colour estimates of chlorophyll concentration. Making use of a new merged ocean-colour product, from the European Space Agency (ESA) Climate Change Initiative, and in situ data in the region, we test the performance of a series of ocean-colour chlorophyll algorithms. We find that standard algorithms systematically overestimate chlorophyll when compared with the in situ data. To investigate this bias we develop an ocean-colour model for the Red Sea, parameterised to data collected during the Tara Oceans expedition, that estimates remote-sensing reflectance as a function of chlorophyll concentration. We used the Red Sea model to tune the standard chlorophyll algorithms and the overestimation in chlorophyll originally observed was corrected. Results suggest that the overestimation was likely due to an excess of CDOM absorption per unit chlorophyll in the Red Sea when compared with average global conditions. However, we recognise that additional information is required to test the influence of other potential sources of the overestimation, such as aeolian dust, and we discuss uncertainties in the datasets used. We present a series of regional chlorophyll algorithms for the Red Sea, designed for a suite of ocean-colour sensors, that may be used for further testing.en
dc.language.isoenen
dc.publisherElsevier BVen
dc.relation.urlhttp://linkinghub.elsevier.com/retrieve/pii/S0034425715001662en
dc.rightsNOTICE: this is the author’s version of a work that was accepted for publication in Remote Sensing of Environment. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Remote Sensing of Environment, 18 May 2015. DOI: 10.1016/j.rse.2015.04.024en
dc.subjectPhytoplanktonen
dc.subjectOcean colouren
dc.subjectRemote sensingen
dc.subjectChlorophyllen
dc.subjectRed Seaen
dc.subjectValidationen
dc.subjectColoured dissolved organic matteren
dc.titleRegional ocean-colour chlorophyll algorithms for the Red Seaen
dc.typeArticleen
dc.contributor.departmentRed Sea Research Center (RSRC)en
dc.contributor.departmentEarth Science and Engineering Programen
dc.identifier.journalRemote Sensing of Environmenten
dc.eprint.versionPost-printen
dc.contributor.institutionPlymouth Marine Laboratory (PML), Prospect Place, The Hoe, Plymouth PL1 3DH, UKen
dc.contributor.institutionNational Centre for Earth Observation, PML, Plymouth PL1 3DH, UKen
dc.contributor.institutionSchool of Marine Sciences, University of Maine, Orono, ME 04469-5741, USAen
dc.contributor.affiliationKing Abdullah University of Science and Technology (KAUST)en
kaust.authorZarokanellos, Nikolaosen
kaust.authorJones, Burtonen
kaust.authorHoteit, Ibrahimen
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