{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,3,9]],"date-time":"2026-03-09T05:40:56Z","timestamp":1773034856004,"version":"3.50.1"},"reference-count":51,"publisher":"MDPI AG","issue":"22","license":[{"start":{"date-parts":[[2019,11,7]],"date-time":"2019-11-07T00:00:00Z","timestamp":1573084800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Remote Sensing"],"abstract":"<jats:p>Remote-sensing reflectance data collected by ocean colour satellites are processed using bio-optical algorithms to retrieve biogeochemical properties of the ocean. One such important property is the concentration of chlorophyll-a, an indicator of phytoplankton biomass that serves a multitude of purposes in various ocean science studies. Here, the performance of two generic chlorophyll-a algorithms (i.e., a band ratio one, Ocean Colour X (OCx), and a semi-analytical one, Garver\u2013Siegel Maritorena (GSM)) was assessed against two large in situ datasets of chlorophyll-a concentration collected between 1999 and 2016 in the Northeast Pacific (NEP) and Northwest Atlantic (NWA) for three ocean colour sensors: Sea-viewing Wide Field-of-view Sensor (SeaWiFS), Moderate Resolution Imaging Spectroradiometer (MODIS), and Visible Infrared Imaging Radiometer Suite (VIIRS). In addition, new regionally-tuned versions of these two algorithms are presented, which reduced the mean error (mg m\u22123) of chlorophyll-a concentration modelled by OCx in the NWA from \u22120.40, \u22120.58 and \u22120.45 to 0.037, \u22120.087 and \u22120.018 for MODIS, SeaWiFS, and VIIRS respectively, and \u22120.34 and \u22120.36 to \u22120.0055 and \u22120.17 for SeaWiFS and VIIRS in the NEP. An analysis of the uncertainties in chlorophyll-a concentration retrieval showed a strong seasonal pattern in the NWA, which could be attributed to changes in phytoplankton community composition, but no long-term trends were found for all sensors and regions. It was also found that removing the 443 nm waveband for the OCx algorithms significantly improved the results in the NWA. Overall, GSM performed better than the OCx algorithms in both regions for all three sensors but generated fewer chlorophyll-a retrievals than the OCx algorithms.<\/jats:p>","DOI":"10.3390\/rs11222609","type":"journal-article","created":{"date-parts":[[2019,11,7]],"date-time":"2019-11-07T11:17:25Z","timestamp":1573125445000},"page":"2609","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":31,"title":["Evaluation of Satellite-Based Algorithms to Retrieve Chlorophyll-a Concentration in the Canadian Atlantic and Pacific Oceans"],"prefix":"10.3390","volume":"11","author":[{"ORCID":"https:\/\/orcid.org\/0000-0001-5113-2378","authenticated-orcid":false,"given":"Stephanie","family":"Clay","sequence":"first","affiliation":[{"name":"Takuvik Joint International Laboratory, Laval University-CNRS, Quebec City, QC G1V 0A6, Canada"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-8002-3402","authenticated-orcid":false,"given":"Angelica","family":"Pe\u00f1a","sequence":"additional","affiliation":[{"name":"Institute of Ocean Sciences, Fisheries and Oceans Canada, Sidney, BC V8L 5T5, Canada"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Brendan","family":"DeTracey","sequence":"additional","affiliation":[{"name":"Bedford Institute of Oceanography, Fisheries and Oceans Canada, Dartmouth, NS B2Y 4A2, Canada"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-9446-0005","authenticated-orcid":false,"given":"Emmanuel","family":"Devred","sequence":"additional","affiliation":[{"name":"Bedford Institute of Oceanography, Fisheries and Oceans Canada, Dartmouth, NS B2Y 4A2, Canada"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2019,11,7]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","unstructured":"Vargas, M., Brown, C.W., and Sapiano, M.R.P. (2009). Phenology of marine phytoplankton from satellite ocean color measurements. Geophys. Res. Lett., 36.","DOI":"10.1029\/2008GL036006"},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"152","DOI":"10.1016\/j.ecolind.2011.07.010","article-title":"Phytoplankton phenology in the global ocean","volume":"14","author":"Racault","year":"2012","journal-title":"Ecol. Indic."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"181","DOI":"10.1002\/2013GB004743","article-title":"Global assessment of ocean carbon export by combining satellite observations and food-web models","volume":"28","author":"Siegel","year":"2014","journal-title":"Glob. Biogeochem. Cycles"},{"key":"ref_4","doi-asserted-by":"crossref","unstructured":"Toming, K., Kutser, T., Uiboupin, R., Arikas, A., Vahter, K., and Paavel, B. (2017). Mapping Water Quality Parameters with Sentinel-3 Ocean and Land Colour Instrument imagery in the Baltic Sea. Remote Sens., 9.","DOI":"10.3390\/rs9101070"},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"127","DOI":"10.1016\/S0924-7963(03)00016-2","article-title":"Assimilation of ocean colour data into a biochemical model of the North Atlantic: Part 1. Data assimilation experiments","volume":"40\u201341","author":"Natvik","year":"2003","journal-title":"J. Mar. Syst."},{"key":"ref_6","unstructured":"IOCCG (2009). Remote Sensing in Fisheries and Aquaculture, IOCCG. Reports of the International Ocean Colour Coordinating Group."},{"key":"ref_7","doi-asserted-by":"crossref","unstructured":"McIver, R., Breeze, H., and Devred, E. (2018). Satellite remote-sensing observations for definitions of areas for marine conservation: Case study of the Scotian Slope, Eastern Canada. Remote Sens. Environ., 214.","DOI":"10.1016\/j.rse.2018.05.017"},{"key":"ref_8","unstructured":"Johnson, C., Devred, E., Casault, B., Head, E., Cogswell, A., and Spry, J. (2019, November 05). Optical, Chemical, and Biological Oceanographic Conditions on the Scotian Shelf and in the Eastern Gulf of Maine during 2015. Available online: http:\/\/publications.gc.ca\/site\/eng\/9.833512\/publication.html."},{"key":"ref_9","unstructured":"Hannah, C.G., and McKinnell, S. (2016). Applying Remote Sensing Data to Fisheries Management in BC, Technical Report."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"24937","DOI":"10.1029\/98JC02160","article-title":"Ocean color chlorophyll algorithm for SeaWiFS","volume":"103","author":"Maritorena","year":"1998","journal-title":"J. Geophys. Res."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"2019","DOI":"10.1364\/AO.52.002019","article-title":"Generalized ocean color inversion model for retrieving marine inherent optical properties","volume":"52","author":"Werdell","year":"2013","journal-title":"Appl. Opt."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"122","DOI":"10.1016\/j.rse.2005.07.001","article-title":"An improved in situ bio-optical dataset for ocean colour algorithm development and satellite data production validation","volume":"98","author":"Werdell","year":"2005","journal-title":"Remote Sens. Environ."},{"key":"ref_13","doi-asserted-by":"crossref","unstructured":"Gower, J. (2015). On the use of satellite-measured chlorophyll fluorescence for monitoring coastal waters. Int. J. Remote Sens.","DOI":"10.1080\/01431161.2015.1111542"},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"517","DOI":"10.1080\/01431160600821127","article-title":"The MERIS case 2 water algorithm","volume":"28","author":"Doerffer","year":"2007","journal-title":"Int. J. Remote Sens."},{"key":"ref_15","doi-asserted-by":"crossref","unstructured":"Lalibert\u00e9, J., Larouche, P., Devred, E., and Craig, S. (2018). Chlorophyll-a Concentration Retrieval in the Optically Complex Waters of the St. Lawrence Estuary and Gulf Using Principal Component Analysis. Remote Sens., 10.","DOI":"10.3390\/rs10020265"},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"2682","DOI":"10.1080\/01431161.2016.1183834","article-title":"Revisiting empirical ocean-colour algorithms for remote estimation of chlorophyll-a content on a global scale","volume":"37","author":"Hamed","year":"2016","journal-title":"Int. J. Remote Sens."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"535","DOI":"10.5589\/m12-045","article-title":"Evaluation of ocean color algorithms in the southeastern Beaufort Sea, Canadian Arctic: New parameterization using SeaWiFS, MODIS, and MERIS spectral bands","volume":"38","author":"Larouche","year":"2012","journal-title":"Can. J. Remote Sens."},{"key":"ref_18","first-page":"55","article-title":"Phytoplankton in Surface Waters along Line P and off the West Coast of Vancouver Island","volume":"Volume 3266","author":"Chandler","year":"2018","journal-title":"State of the Physical, Biological and Selected Fishery Resources of Pacific Canadian Marine Ecosystems in 2017"},{"key":"ref_19","first-page":"329","article-title":"Pigment transformation and vertical flux in an area of convergence in the North Atlantic","volume":"40","author":"Head","year":"1993","journal-title":"Deep-Sea Res. II"},{"key":"ref_20","unstructured":"Hooker, S.B. (2005). The BIO method, The Second SeaWiFS HPLC Analysis Round-Robin Experiment (SeaHARRE-2)."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"29","DOI":"10.3354\/meps195029","article-title":"Separation of chlorophylls and carotenoids from marine phytoplankton: A new HPLC method using a reversed phase C8 column and pyridine-containing mobile phases","volume":"195","author":"Zapata","year":"2000","journal-title":"Mar. Ecol. Prog. Ser."},{"key":"ref_22","unstructured":"Hijmans, R.J. (2019, November 05). Geosphere: Spherical Trigonometry (R Package Version 1.5-7). Available online: http:\/\/cran.nexr.com\/web\/packages\/geosphere\/index.html."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"2705","DOI":"10.1364\/AO.41.002705","article-title":"Optimization of a semi-analytical ocean color model for global-scale applications","volume":"41","author":"Maritorena","year":"2002","journal-title":"Appl. Opt."},{"key":"ref_24","unstructured":"R Core Team (2016). R: A Language and Environment for Statistical Computing, R Foundation for Statistical Computing."},{"key":"ref_25","doi-asserted-by":"crossref","unstructured":"Davison, A.C., and Hinkley, D.V. (1997). Bootstrap Methods and Their Applications, Cambridge University Press.","DOI":"10.1017\/CBO9780511802843"},{"key":"ref_26","unstructured":"Canty, A., and Ripley, B.D. (2019, November 05). Boot: Bootstrap R (S-Plus) Functions (R Package Version 1.3-22). Available online: https:\/\/cran.rapporter.net\/bin\/linux\/ubuntu\/disco-cran35\/Packages."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"18607","DOI":"10.1029\/96JC03243","article-title":"Inherent optical property inversion of ocean color spectra and its biogeochemical interpretation: 1. Time series from the Sargasso Sea","volume":"102","author":"Garver","year":"1997","journal-title":"J. Geophys. Res. Oceans"},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"10909","DOI":"10.1029\/JD093iD09p10909","article-title":"A semianalytic radiance model of ocean color","volume":"93","author":"Gordon","year":"1988","journal-title":"J. Geophys. Res."},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"8710","DOI":"10.1364\/AO.36.008710","article-title":"Absorption spectrum (380\u2013700 nm) of pure water. II. Integrating measurements","volume":"36","author":"Pope","year":"1997","journal-title":"Appl. Opt."},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"177","DOI":"10.1364\/AO.20.000177","article-title":"Optical properties of the clearest natural waters (200\u2013800 nm)","volume":"20","author":"Smith","year":"1981","journal-title":"Appl. Opt."},{"key":"ref_31","unstructured":"Lee, Z.P. (2006). Remote Sensing of Inherent Optical Properties: Fundamentals, Tests of Algorithms, and Applications, IOCCG. Reports of the International Oean-Colour Coordinating Group, No. 5."},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"5755","DOI":"10.1364\/AO.41.005755","article-title":"Deriving inherent optical properties from water color: A multi-band quasi-analytical algorithm for optically deep waters","volume":"41","author":"Lee","year":"2002","journal-title":"Appl. Opt."},{"key":"ref_33","doi-asserted-by":"crossref","unstructured":"Bricaud, A., Claustre, H., and Oubelkheir, K. (2004). Natural variability of phytoplankton absorption in oceanic waters: influence of the size structure of algal populations. J. Geophys. Res., 110.","DOI":"10.1029\/2004JC002419"},{"key":"ref_34","unstructured":"Legendre, P. (2019, November 05). Lmodel2: Model II Regression (R Package Version 1.7-3). Available online: https:\/\/cran.r-project.org\/web\/packages\/lmodel2\/index.html."},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"7404","DOI":"10.1364\/OE.26.007404","article-title":"Performance metrics for the assessment of satellite data products: An ocean color case study","volume":"26","author":"Seegers","year":"2018","journal-title":"Opt. Express"},{"key":"ref_36","doi-asserted-by":"crossref","unstructured":"Brewin, B., Sathyendranath, S., M\u00fcller, D., Brockmann, C., Deschamps, P.Y., Devred, E., Doerffer, R., Fomferra, N., Franz, B., and Grant, M. (2015). The Ocean Colour Climate Change Initiative: III. A round-robin comparison on in-water bio-optical algorithms. Remote Sens. Environ., 162.","DOI":"10.1016\/j.rse.2013.09.016"},{"key":"ref_37","doi-asserted-by":"crossref","unstructured":"Wickham, H. (2009). ggplot2: Elegant Graphics for Data Analysis, Springer.","DOI":"10.1007\/978-0-387-98141-3"},{"key":"ref_38","doi-asserted-by":"crossref","first-page":"1206","DOI":"10.4319\/lo.1994.39.5.1206","article-title":"The trophic status of various oceanic provinces as revealed by phytoplankton pigment signatures","volume":"39","author":"Claustre","year":"1994","journal-title":"Limnol. Oceanogr."},{"key":"ref_39","unstructured":"Jeffrey, S.W., Mantoura, R.F.C., and Wright, S.W. (1997). Introduction to marine phytoplankton and their pigment signature. Phytoplankton Pigments in Oceanography: Guidelines to Modern Methods, UNESCO Publishing."},{"key":"ref_40","doi-asserted-by":"crossref","first-page":"1539","DOI":"10.1080\/01431160500382857","article-title":"Empirical and semi-analytical chlorophyll algorithms in the south-western Atlantic coastal region (25\u201340\u00b0S and 60\u201345\u00b0W)","volume":"27","author":"Garcia","year":"2006","journal-title":"Int. J. Remote Sens."},{"key":"ref_41","doi-asserted-by":"crossref","first-page":"21","DOI":"10.1007\/s13131-010-0047-6","article-title":"Ocean color products retrieval and validation around China coast with MODIS","volume":"29","author":"Sun","year":"2010","journal-title":"Acta Oceanol. Sin."},{"key":"ref_42","doi-asserted-by":"crossref","first-page":"151","DOI":"10.3389\/fmars.2017.00151","article-title":"Simplifying Regional Tuning of MODIS Algorithms for Monitoring Chlorophyll-a in Coastal Waters","volume":"4","author":"Jiang","year":"2017","journal-title":"Front. Mar. Sci."},{"key":"ref_43","unstructured":"Hooker, S., and Firestone, E. (1992). An Overview of SeaWiFS and Ocean Color."},{"key":"ref_44","doi-asserted-by":"crossref","first-page":"6701","DOI":"10.1364\/AO.40.006701","article-title":"Calibration of SeaWiFS. II. Vicarious techniques","volume":"40","author":"Eplee","year":"2001","journal-title":"Appl. Opt."},{"key":"ref_45","doi-asserted-by":"crossref","first-page":"187","DOI":"10.1093\/plankt\/20.2.187","article-title":"Pigments and species compositon of natural phytoplankton populations: effect on the absorption spectra","volume":"20","author":"Stuart","year":"1998","journal-title":"J. Plankton Res."},{"key":"ref_46","doi-asserted-by":"crossref","first-page":"249","DOI":"10.1080\/014311601449925","article-title":"Remote sensing of phytoplankton pigments: A comparison of empirical and theoretical approaches","volume":"22","author":"Sathyendranath","year":"2001","journal-title":"Int. J. Remote Sens."},{"key":"ref_47","doi-asserted-by":"crossref","unstructured":"Devred, E., Sathyendranath, S., Stuart, V., Maass, H., Ulloa, O., and Platt, T. (2006). A two-component model of phytoplankton absorption in the open ocean: theory and applications. J. Geophys. Res., 111.","DOI":"10.1029\/2005JC002880"},{"key":"ref_48","doi-asserted-by":"crossref","first-page":"59","DOI":"10.3354\/meps272059","article-title":"Discrimination of diatoms from other phytoplankton using ocean-colour data","volume":"272","author":"Sathyendranath","year":"2004","journal-title":"Mar. Ecol. Prog. Ser."},{"key":"ref_49","unstructured":"IOCCG (2010). Atmospheric Correction for Remotely-Sensed Ocean-Colour Products, IOCCG. Reports of the International Ocean Colour Coordinating Group."},{"key":"ref_50","doi-asserted-by":"crossref","first-page":"709","DOI":"10.4319\/lo.1977.22.4.0709","article-title":"Analysis of variation in ocean color","volume":"22","author":"Morel","year":"1977","journal-title":"Limnol. Oceanogr."},{"key":"ref_51","doi-asserted-by":"crossref","unstructured":"Carswell, T., Costa, M., Young, E., Komick, N., Gower, J., and Sweeting, R. (2017). Evaluation of MODIS-Aqua Atmospheric Correction and Chlorophyll Products of Western North American Coastal Waters Based on 13 Years of Data. Remote Sens., 9.","DOI":"10.3390\/rs9101063"}],"container-title":["Remote Sensing"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2072-4292\/11\/22\/2609\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T13:32:32Z","timestamp":1760189552000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2072-4292\/11\/22\/2609"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2019,11,7]]},"references-count":51,"journal-issue":{"issue":"22","published-online":{"date-parts":[[2019,11]]}},"alternative-id":["rs11222609"],"URL":"https:\/\/doi.org\/10.3390\/rs11222609","relation":{},"ISSN":["2072-4292"],"issn-type":[{"value":"2072-4292","type":"electronic"}],"subject":[],"published":{"date-parts":[[2019,11,7]]}}}