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Cael BB, Bisson K, Boss E, Dutkiewicz S, Henson S. Global climate-change trends detected in indicators of ocean ecology. Nature 2023; 619:551-554. [PMID: 37438519 PMCID: PMC10356596 DOI: 10.1038/s41586-023-06321-z] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2023] [Accepted: 06/14/2023] [Indexed: 07/14/2023]
Abstract
Strong natural variability has been thought to mask possible climate-change-driven trends in phytoplankton populations from Earth-observing satellites. More than 30 years of continuous data were thought to be needed to detect a trend driven by climate change1. Here we show that climate-change trends emerge more rapidly in ocean colour (remote-sensing reflectance, Rrs), because Rrs is multivariate and some wavebands have low interannual variability. We analyse a 20-year Rrs time series from the Moderate Resolution Imaging Spectroradiometer (MODIS) aboard the Aqua satellite, and find significant trends in Rrs for 56% of the global surface ocean, mainly equatorward of 40°. The climate-change signal in Rrs emerges after 20 years in similar regions covering a similar fraction of the ocean in a state-of-the-art ecosystem model2, which suggests that our observed trends indicate shifts in ocean colour-and, by extension, in surface-ocean ecosystems-that are driven by climate change. On the whole, low-latitude oceans have become greener in the past 20 years.
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Affiliation(s)
- B B Cael
- National Oceanography Centre, Southampton, UK.
| | - Kelsey Bisson
- Department of Botany and Plant Pathology, Oregon State University, Corvallis, OR, USA
| | | | - Stephanie Dutkiewicz
- Center for Global Change Science, Massachusetts Institute of Technology, Cambridge, MA, USA
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2
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Abstract
Retrieval of water properties from satellite-borne imagers viewing oceans and coastal areas in the visible region of the spectrum requires removing the effect of the atmosphere, which contributes approximately 80–90% of the measured radiance over the open ocean in the blue spectral region. The Gordon and Wang algorithm originally developed for SeaWiFS (and used with other NASA sensors, e.g., MODIS) forms the basis for many atmospheric removal (correction) procedures. It was developed for application to imagery obtained over the open ocean (Case 1 waters), where the aerosol is usually non-absorbing, and is used operationally to process global data from SeaWiFS, MODIS and VIIRS. Here, I trace the evolution of this algorithm from early NASA aircraft experiments through the CZCS, OCTS, SeaWiFs, MERIS, and finally the MODIS sensors. Strategies to extend the algorithm to situations where the aerosol is strongly absorbing are examined. Its application to sensors with additional and unique capabilities is sketched. Problems associated with atmospheric correction in coastal waters are described.
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3
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Hammond ML, Beaulieu C, Henson SA, Sahu SK. Regional surface chlorophyll trends and uncertainties in the global ocean. Sci Rep 2020; 10:15273. [PMID: 32943692 PMCID: PMC7498587 DOI: 10.1038/s41598-020-72073-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2019] [Accepted: 08/21/2020] [Indexed: 11/09/2022] Open
Abstract
Changes in marine primary productivity are key to determine how climate change might impact marine ecosystems and fisheries. Satellite ocean color sensors provide coverage of global ocean chlorophyll with a combined record length of ~ 20 years. Coupled physical–biogeochemical models can inform on expected changes and are used here to constrain observational trend estimates and their uncertainty. We produce estimates of ocean surface chlorophyll trends, by using Coupled Model Intercomparison Project (CMIP5) models to form priors as a “first guess”, which are then updated using satellite observations in a Bayesian spatio-temporal model. Regional chlorophyll trends are found to be significantly different from zero in 18/23 regions, in the range ± 1.8% year−1. A global average of these regional trends shows a net positive trend of 0.08 ± 0.35% year−1, highlighting the importance of considering chlorophyll changes at a regional level. We compare these results with estimates obtained with the commonly used “vague” prior, representing no independent knowledge; coupled model priors are shown to slightly reduce trend magnitude and uncertainties in most regions. The statistical model used here provides a robust framework for making best use of all available information and can be applied to improve understanding of global change.
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Affiliation(s)
- Matthew L Hammond
- National Oceanography Centre, European Way, Southampton, SO14 3ZH, UK. .,Ocean and Earth Science, University of Southampton, Southampton, UK.
| | - Claudie Beaulieu
- Ocean and Earth Science, University of Southampton, Southampton, UK.,Ocean Sciences Department, University of California Santa Cruz, Santa Cruz, USA
| | | | - Sujit K Sahu
- Southampton Statistical Sciences Research Institute, University of Southampton, Southampton, UK
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4
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Nohe A, Goffin A, Tyberghein L, Lagring R, De Cauwer K, Vyverman W, Sabbe K. Marked changes in diatom and dinoflagellate biomass, composition and seasonality in the Belgian Part of the North Sea between the 1970s and 2000s. THE SCIENCE OF THE TOTAL ENVIRONMENT 2020; 716:136316. [PMID: 32036126 DOI: 10.1016/j.scitotenv.2019.136316] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/06/2019] [Revised: 12/20/2019] [Accepted: 12/22/2019] [Indexed: 06/10/2023]
Abstract
In the last decades, the North Sea has undergone intense environmental changes which have led to regime shifts that affected all trophic levels. Since the 1970s, both increases and decreases in phytoplankton biomass and production have been reported from different parts of the North Sea. Such conflicting observations may be partly caused by methodological differences, but also reflect regional differences related to bathymetry, hydrodynamics, climate, riverine and Atlantic influence. The Belgian part of the North Sea (BPNS) is a hydrodynamically and bathymetrically complex area under strong human influence, which has been characterized by eutrophication (up to the 1980s) and de-eutrophication (1990s onwards), and pronounced long-term changes in turbidity and water temperature. We used a newly recovered and standardized historic dataset, the Belgian Phytoplankton Database (Nohe et al., 2018), to compare the biomass, composition and seasonality of diatom and dinoflagellate assemblages, two key components of the plankton in the BPNS, between the 1970s and 2000s. Diatoms, especially large-sized taxa, showed an increase from late winter to summer, resulting in a more intense and extended growing season in the 2000s. Dinoflagellates increased year-round but especially in summer. Both diatom and dinoflagellate blooms showed a clear shift towards an earlier bloom start. In addition, while in the 1970s distinct seasonal community types were present, a striking seasonal homogenization in community structure had occurred by the 2000s. Finally, we observed a pronounced increase in the abundance of harmful diatom and dinoflagellate genera. The observed changes are most likely due to an increase in sea surface temperature and water transparency, and changes in nutrient loads and ratios. Our study underscores the importance of recovering previously inaccessible historic data as they can offer unprecedented insights into long-term change in marine ecosystems, which are essential for properly evaluating the impact of human activities on these ecosystems.
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Affiliation(s)
- Anja Nohe
- Ghent University, Department of Biology, Laboratory of Protistology & Aquatic Ecology, Krijgslaan 281 (S8), 9000 Ghent, Belgium
| | - Annelies Goffin
- Flanders Marine Institute, Wandelaarkaai 7, 8400 Ostend, Belgium
| | | | - Ruth Lagring
- Operational Directorate Natural Environment, Royal Belgian Institute of Natural Sciences, Vautierstraat 29, 1000 Brussels, Belgium
| | - Karien De Cauwer
- Operational Directorate Natural Environment, Royal Belgian Institute of Natural Sciences, Vautierstraat 29, 1000 Brussels, Belgium
| | - Wim Vyverman
- Ghent University, Department of Biology, Laboratory of Protistology & Aquatic Ecology, Krijgslaan 281 (S8), 9000 Ghent, Belgium
| | - Koen Sabbe
- Ghent University, Department of Biology, Laboratory of Protistology & Aquatic Ecology, Krijgslaan 281 (S8), 9000 Ghent, Belgium.
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5
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Cavicchioli R, Ripple WJ, Timmis KN, Azam F, Bakken LR, Baylis M, Behrenfeld MJ, Boetius A, Boyd PW, Classen AT, Crowther TW, Danovaro R, Foreman CM, Huisman J, Hutchins DA, Jansson JK, Karl DM, Koskella B, Mark Welch DB, Martiny JBH, Moran MA, Orphan VJ, Reay DS, Remais JV, Rich VI, Singh BK, Stein LY, Stewart FJ, Sullivan MB, van Oppen MJH, Weaver SC, Webb EA, Webster NS. Scientists' warning to humanity: microorganisms and climate change. Nat Rev Microbiol 2019; 17:569-586. [PMID: 31213707 PMCID: PMC7136171 DOI: 10.1038/s41579-019-0222-5] [Citation(s) in RCA: 673] [Impact Index Per Article: 134.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/22/2019] [Indexed: 11/27/2022]
Abstract
In the Anthropocene, in which we now live, climate change is impacting most life on Earth. Microorganisms support the existence of all higher trophic life forms. To understand how humans and other life forms on Earth (including those we are yet to discover) can withstand anthropogenic climate change, it is vital to incorporate knowledge of the microbial 'unseen majority'. We must learn not just how microorganisms affect climate change (including production and consumption of greenhouse gases) but also how they will be affected by climate change and other human activities. This Consensus Statement documents the central role and global importance of microorganisms in climate change biology. It also puts humanity on notice that the impact of climate change will depend heavily on responses of microorganisms, which are essential for achieving an environmentally sustainable future.
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Affiliation(s)
- Ricardo Cavicchioli
- School of Biotechnology and Biomolecular Sciences, The University of New South Wales, Sydney, NSW, Australia.
| | - William J Ripple
- Department of Forest Ecosystems and Society, Oregon State University, Corvallis, OR, USA
| | - Kenneth N Timmis
- Institute of Microbiology, Technical University Braunschweig, Braunschweig, Germany
| | - Farooq Azam
- Scripps Institution of Oceanography, University of California San Diego, La Jolla, CA, USA
| | - Lars R Bakken
- Faculty of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences, Ås, Norway
| | - Matthew Baylis
- Institute of Infection and Global Health, University of Liverpool, Liverpool, UK
| | - Michael J Behrenfeld
- Department of Botany and Plant Pathology, Oregon State University, Corvallis, OR, USA
| | - Antje Boetius
- Alfred Wegener Institute, Helmholtz Center for Marine and Polar Research, Bremerhaven, Germany
- Max Planck Institute for Marine Microbiology, Bremen, Germany
| | - Philip W Boyd
- Institute for Marine and Antarctic Studies, University of Tasmania, Hobart, TAS, Australia
| | - Aimée T Classen
- Rubenstein School of Environment and Natural Resources, and The Gund Institute for Environment, University of Vermont, Burlington, VT, USA
| | | | - Roberto Danovaro
- Department of Life and Environmental Sciences, Polytechnic University of Marche, Ancona, Italy
- Stazione Zoologica Anton Dohrn, Naples, Italy
| | - Christine M Foreman
- Center for Biofilm Engineering, and Chemical and Biological Engineering Department, Montana State University, Bozeman, MT, USA
| | - Jef Huisman
- Department of Freshwater and Marine Ecology, Institute for Biodiversity and Ecosystem Dynamics, University of Amsterdam, Amsterdam, Netherlands
| | - David A Hutchins
- Department of Biological Sciences, Marine and Environmental Biology Section, University of Southern California, Los Angeles, CA, USA
| | - Janet K Jansson
- Biological Sciences Division, Earth and Biological Sciences Directorate, Pacific Northwest National Laboratory, Richland, WA, USA
| | - David M Karl
- Daniel K. Inouye Center for Microbial Oceanography: Research and Education, School of Ocean and Earth Science & Technology, University of Hawaii at Manoa, Honolulu, HI, USA
| | - Britt Koskella
- Department of Integrative Biology, University of California, Berkeley, Berkeley, CA, USA
| | | | - Jennifer B H Martiny
- Department of Ecology and Evolutionary Biology, University of California, Irvine, Irvine, CA, USA
| | - Mary Ann Moran
- Department of Marine Sciences, University of Georgia, Athens, GA, USA
| | - Victoria J Orphan
- Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA, USA
| | - David S Reay
- School of Geosciences, University of Edinburgh, Edinburgh, UK
| | - Justin V Remais
- Division of Environmental Health Sciences, School of Public Health, University of California, Berkeley, Berkeley, CA, USA
| | - Virginia I Rich
- Microbiology Department, and the Byrd Polar and Climate Research Center, The Ohio State University, Columbus, OH, USA
| | - Brajesh K Singh
- Hawkesbury Institute for the Environment, and Global Centre for Land-Based Innovation, Western Sydney University, Penrith, NSW, Australia
| | - Lisa Y Stein
- Department of Biological Sciences, University of Alberta, Edmonton, AB, Canada
| | - Frank J Stewart
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, GA, USA
| | - Matthew B Sullivan
- Department of Microbiology, and Department of Civil, Environmental and Geodetic Engineering, and the Byrd Polar and Climate Research Center, The Ohio State University, Columbus, OH, USA
| | - Madeleine J H van Oppen
- School of BioSciences, The University of Melbourne, Parkville, VIC, Australia
- Australian Institute of Marine Science, Townsville, QLD, Australia
| | - Scott C Weaver
- Department of Microbiology and Immunology, and Institute for Human Infections and Immunity, University of Texas Medical Branch, Galveston, TX, USA
| | - Eric A Webb
- Department of Biological Sciences, Marine and Environmental Biology Section, University of Southern California, Los Angeles, CA, USA
| | - Nicole S Webster
- Australian Institute of Marine Science, Townsville, QLD, Australia
- Australian Centre for Ecogenomics, University of Queensland, Brisbane, QLD, Australia
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6
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Wang S, Lee Z, Shang S, Li J, Zhang B, Lin G. Deriving inherent optical properties from classical water color measurements: Forel-Ule index and Secchi disk depth. OPTICS EXPRESS 2019; 27:7642-7655. [PMID: 30876326 DOI: 10.1364/oe.27.007642] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/28/2018] [Accepted: 12/13/2018] [Indexed: 06/09/2023]
Abstract
Secchi disk depth (ZSD) and Forel-Ule index (FUI) are the two oldest and easiest measurements of water optical properties based on visual determination. With an overarching objective to obtain water inherent optical properties (IOPs) using these historical measurements, this study presents a model for associating remote-sensing reflectance (Rrs) with FUI and ZSD. Based upon this, a scheme (FZ2ab) for converting FUI and ZSD to absorption (a) and backscattering coefficients (bb) is developed and evaluated. For a data set from HydroLight simulations, the difference is <11% between FZ2ab-derived a and known a, and <28% between FZ2ab-derived bb and known bb. Further, for a data set from field measurements, the difference is < 30% between FZ2ab-derived a and measured a. These results indicate that FZ2ab can bridge the gap between historical measurements and the focus of IOP measurements in modern marine optics, and potentially extend our knowledge on the bio-optical properties of global seas to the past century through the historical measurements of FUI and ZSD.
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7
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Abstract
Monitoring changes in marine phytoplankton is important as they form the foundation of the marine food web and are crucial in the carbon cycle. Often Chlorophyll-a (Chl-a) is used to track changes in phytoplankton, since there are global, regular satellite-derived estimates. However, satellite sensors do not measure Chl-a directly. Instead, Chl-a is estimated from remote sensing reflectance (RRS): the ratio of upwelling radiance to the downwelling irradiance at the ocean’s surface. Using a model, we show that RRS in the blue-green spectrum is likely to have a stronger and earlier climate-change-driven signal than Chl-a. This is because RRS has lower natural variability and integrates not only changes to in-water Chl-a, but also alterations in other optically important constituents. Phytoplankton community structure, which strongly affects ocean optics, is likely to show one of the clearest and most rapid signatures of changes to the base of the marine ecosystem. Changes in chlorophyll-a are used as an indirect proxy for monitoring global changes in marine phytoplankton. Here the authors show that remote sensing reflectance (RRS), such as the ratio of upwelling versus downwelling light at the ocean’s surface, has a stronger and earlier climate-change-driven signal over the 21st century.
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8
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Macias D, Garcia-Gorriz E, Stips A. Deep winter convection and phytoplankton dynamics in the NW Mediterranean Sea under present climate and future (horizon 2030) scenarios. Sci Rep 2018; 8:6626. [PMID: 29700363 PMCID: PMC5919909 DOI: 10.1038/s41598-018-24965-0] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2017] [Accepted: 04/06/2018] [Indexed: 11/09/2022] Open
Abstract
Deep water convection (DC) in winter is one of the major processes driving open-ocean primary productivity in the Northwestern Mediterranean Sea. DC is highly variable in time, depending on the specific conditions (stratification, circulation and ocean-atmosphere interactions) of each specific winter. This variability also drives the interannual oscillations of open-ocean primary productivity in this important region for many commercially-important fish species. We use a coupled model system to 1) understand to what extent DC impacts phytoplankton seasonality in the present-day and 2) to explore potential changes in future scenarios (~2030). Our model represents quite accurately the present-day characteristics of DC and its importance for open-ocean phytoplankton blooms. However, for the future scenarios the importance of deep nutrients in fertilizing the euphotic layer of the NW Mediterranean decreases. The model simulates changes in surface density and on the levels of kinetic energy that make mesoscale activity associated with horizontal currents to become a more important fertilization mechanism, inducing subsequently phenological changes in seasonal plankton cycles. Because of our focus on the open-sea, an exact quantification of the impact of those changes on the overall biological production of the NW Mediterranean cannot be made at the moment.
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Affiliation(s)
- Diego Macias
- European Commission, Joint Research Centre, Directorate D- Sustainable Resources, Via E. Fermi, 21027, Ispra, VA, Italy.
| | - Elisa Garcia-Gorriz
- European Commission, Joint Research Centre, Directorate D- Sustainable Resources, Via E. Fermi, 21027, Ispra, VA, Italy
| | - Adolf Stips
- European Commission, Joint Research Centre, Directorate D- Sustainable Resources, Via E. Fermi, 21027, Ispra, VA, Italy
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9
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Hue-Angle Product for Low to Medium Spatial Resolution Optical Satellite Sensors. REMOTE SENSING 2018. [DOI: 10.3390/rs10020180] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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10
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Henson SA. Slow science: the value of long ocean biogeochemistry records. PHILOSOPHICAL TRANSACTIONS. SERIES A, MATHEMATICAL, PHYSICAL, AND ENGINEERING SCIENCES 2014; 372:rsta.2013.0334. [PMID: 25157192 PMCID: PMC4150291 DOI: 10.1098/rsta.2013.0334] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Sustained observations (SOs) have provided invaluable information on the ocean's biology and biogeochemistry for over 50 years. They continue to play a vital role in elucidating the functioning of the marine ecosystem, particularly in the light of ongoing climate change. Repeated, consistent observations have provided the opportunity to resolve temporal and/or spatial variability in ocean biogeochemistry, which has driven exploration of the factors controlling biological parameters and processes. Here, I highlight some of the key breakthroughs in biological oceanography that have been enabled by SOs, which include areas such as trophic dynamics, understanding variability, improved biogeochemical models and the role of ocean biology in the global carbon cycle. In the near future, SOs are poised to make progress on several fronts, including detecting climate change effects on ocean biogeochemistry, high-resolution observations of physical-biological interactions and greater observational capability in both the mesopelagic zone and harsh environments, such as the Arctic. We are now entering a new era for biological SOs, one in which our motivations have evolved from the need to acquire basic understanding of the ocean's state and variability, to a need to understand ocean biogeochemistry in the context of increasing pressure in the form of climate change, overfishing and eutrophication.
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11
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Gregg WW, Rousseaux CS. Decadal trends in global pelagic ocean chlorophyll: A new assessment integrating multiple satellites, in situ data, and models. JOURNAL OF GEOPHYSICAL RESEARCH. OCEANS 2014; 119:5921-5933. [PMID: 26213675 PMCID: PMC4508908 DOI: 10.1002/2014jc010158] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/15/2014] [Accepted: 07/28/2014] [Indexed: 05/19/2023]
Abstract
Quantifying change in ocean biology using satellites is a major scientific objective. We document trends globally for the period 1998-2012 by integrating three diverse methodologies: ocean color data from multiple satellites, bias correction methods based on in situ data, and data assimilation to provide a consistent and complete global representation free of sampling biases. The results indicated no significant trend in global pelagic ocean chlorophyll over the 15 year data record. These results were consistent with previous findings that were based on the first 6 years and first 10 years of the SeaWiFS mission. However, all of the Northern Hemisphere basins (north of 10° latitude), as well as the Equatorial Indian basin, exhibited significant declines in chlorophyll. Trend maps showed the local trends and their change in percent per year. These trend maps were compared with several other previous efforts using only a single sensor (SeaWiFS) and more limited time series, showing remarkable consistency. These results suggested the present effort provides a path forward to quantifying global ocean trends using multiple satellite missions, which is essential if we are to understand the state, variability, and possible changes in the global oceans over longer time scales.
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Affiliation(s)
- Watson W Gregg
- NASA Global Modeling and Assimilation OfficeGreenbelt, Maryland, USA
| | - Cécile S Rousseaux
- NASA Global Modeling and Assimilation OfficeGreenbelt, Maryland, USA
- Universities Space Research AssociationGreenbelt, Maryland, USA
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12
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Raitsos DE, Pradhan Y, Lavender SJ, Hoteit I, McQuatters-Gollop A, Reid PC, Richardson AJ. From silk to satellite: half a century of ocean colour anomalies in the Northeast Atlantic. GLOBAL CHANGE BIOLOGY 2014; 20:2117-2123. [PMID: 24804626 DOI: 10.1111/gcb.12457] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/13/2013] [Accepted: 10/22/2013] [Indexed: 06/03/2023]
Abstract
Changes in phytoplankton dynamics influence marine biogeochemical cycles, climate processes, and food webs, with substantial social and economic consequences. Large-scale estimation of phytoplankton biomass was possible via ocean colour measurements from two remote sensing satellites - the Coastal Zone Colour Scanner (CZCS, 1979-1986) and the Sea-viewing Wide Field-of-view Sensor (SeaWiFS, 1998-2010). Due to the large gap between the two satellite eras and differences in sensor characteristics, comparison of the absolute values retrieved from the two instruments remains challenging. Using a unique in situ ocean colour dataset that spans more than half a century, the two satellite-derived chlorophyll-a (Chl-a) eras are linked to assess concurrent changes in phytoplankton variability and bloom timing over the Northeast Atlantic Ocean and North Sea. Results from this unique re-analysis reflect a clear increasing pattern of Chl-a, a merging of the two seasonal phytoplankton blooms producing a longer growing season and higher seasonal biomass, since the mid-1980s. The broader climate plays a key role in Chl-a variability as the ocean colour anomalies parallel the oscillations of the Northern Hemisphere Temperature (NHT) since 1948.
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Affiliation(s)
- Dionysios E Raitsos
- Plymouth Marine Laboratory (PML), Prospect Place, The Hoe, Plymouth, PL1 3DH, UK
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13
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González Taboada F, Anadón R. Seasonality of North Atlantic phytoplankton from space: impact of environmental forcing on a changing phenology (1998-2012). GLOBAL CHANGE BIOLOGY 2014; 20:698-712. [PMID: 23943398 DOI: 10.1111/gcb.12352] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/29/2012] [Accepted: 07/30/2013] [Indexed: 06/02/2023]
Abstract
Seasonal pulses of phytoplankton drive seasonal cycles of carbon fixation and particle sedimentation, and might condition recruitment success in many exploited species. Taking advantage of long-term series of remotely sensed chlorophyll a (1998-2012), we analyzed changes in phytoplankton seasonality in the North Atlantic Ocean. Phytoplankton phenology was analyzed based on a probabilistic characterization of bloom incidence. This approach allowed us to detect changes in the prevalence of different seasonal cycles and, at the same time, to estimate bloom timing and magnitude taking into account uncertainty in bloom detection. Deviations between different sensors stressed the importance of a prolonged overlap between successive missions to ensure a correct assessment of phenological changes, as well as the advantage of semi-analytical chlorophyll algorithms over empirical ones to reduce biases. Earlier and more intense blooms were detected in the subpolar Atlantic, while advanced blooms of less magnitude were common in the Subtropical gyre. In the temperate North Atlantic, spring blooms advanced their timing and decreased in magnitude, whereas fall blooms delayed and increased their intensity. At the same time, the prevalence of locations with a single autumn/winter bloom or with a bimodal seasonal cycle increased, in consonance with a poleward expansion of subtropical conditions. Changes in bloom timing and magnitude presented a clear signature of environmental factors, especially wind forcing, although changes on incident photosynthetically active radiation and sea surface temperature were also important depending on latitude. Trends in bloom magnitude matched changes in mean chlorophyll a during the study period, suggesting that seasonal peaks drive long-term trends in chlorophyll a concentration. Our results link changes in North Atlantic climate with recent trends in the phenology of phytoplankton, suggesting an intensification of these impacts in the near future.
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Affiliation(s)
- Fernando González Taboada
- Área de Ecología, Dpto. Biología de Organismos y Sistemas, Universidad de Oviedo, C/Valentín Andrés Álvarez s/n, E33071, Oviedo, Asturias, Spain
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14
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Antoine D, Babin M, Berthon JF, Bricaud A, Gentili B, Loisel H, Maritorena S, Stramski D. Shedding light on the sea: André Morel's legacy to optical oceanography. ANNUAL REVIEW OF MARINE SCIENCE 2013; 6:1-21. [PMID: 24015899 DOI: 10.1146/annurev-marine-010213-135135] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
André Morel (1933-2012) was a prominent pioneer of modern optical oceanography, enabling significant advances in this field. Through his forward thinking and research over more than 40 years, he made key contributions that this field needed to grow and to reach its current status. This article first summarizes his career and then successively covers different aspects of optical oceanography where he made significant contributions, from fundamental work on optical properties of water and particles to global oceanographic applications using satellite ocean color observations. At the end, we share our views on André's legacy to our research field and scientific community.
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Affiliation(s)
- David Antoine
- Laboratoire d'Océanographie de Villefranche, Centre National de la Recherche Scientifique (CNRS) and Université Pierre et Marie Curie (Paris 6), Villefranche-sur-Mer 06238, France; , ,
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15
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Wernand MR, van der Woerd HJ, Gieskes WWC. Trends in ocean colour and chlorophyll concentration from 1889 to 2000, worldwide. PLoS One 2013; 8:e63766. [PMID: 23776435 PMCID: PMC3680421 DOI: 10.1371/journal.pone.0063766] [Citation(s) in RCA: 76] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2013] [Accepted: 04/05/2013] [Indexed: 12/02/2022] Open
Abstract
Marine primary productivity is an important agent in the global cycling of carbon dioxide, a major ‘greenhouse gas’, and variations in the concentration of the ocean's phytoplankton biomass can therefore explain trends in the global carbon budget. Since the launch of satellite-mounted sensors globe-wide monitoring of chlorophyll, a phytoplankton biomass proxy, became feasible. Just as satellites, the Forel-Ule (FU) scale record (a hardly explored database of ocean colour) has covered all seas and oceans – but already since 1889. We provide evidence that changes of ocean surface chlorophyll can be reconstructed with confidence from this record. The EcoLight radiative transfer numerical model indicates that the FU index is closely related to chlorophyll concentrations in open ocean regions. The most complete FU record is that of the North Atlantic in terms of coverage over space and in time; this dataset has been used to test the validity of colour changes that can be translated to chlorophyll. The FU and FU-derived chlorophyll data were analysed for monotonously increasing or decreasing trends with the non-parametric Mann-Kendall test, a method to establish the presence of a consistent trend. Our analysis has not revealed a globe-wide trend of increase or decrease in chlorophyll concentration during the past century; ocean regions have apparently responded differentially to changes in meteorological, hydrological and biological conditions at the surface, including potential long-term trends related to global warming. Since 1889, chlorophyll concentrations have decreased in the Indian Ocean and in the Pacific; increased in the Atlantic Ocean, the Mediterranean, the Chinese Sea, and in the seas west and north-west of Japan. This suggests that explanations of chlorophyll changes over long periods should focus on hydrographical and biological characteristics typical of single ocean regions, not on those of ‘the’ ocean.
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Affiliation(s)
- Marcel R Wernand
- Royal Netherlands Institute for Sea Research, Physical Oceanography, Marine Optics & Remote Sensing, Texel, The Netherlands.
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16
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Marine Ecosystems, Biogeochemistry, and Climate. ACTA ACUST UNITED AC 2013. [DOI: 10.1016/b978-0-12-391851-2.00031-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/17/2023]
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17
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Duarte CM, Regaudie-de-Gioux A, Arrieta JM, Delgado-Huertas A, Agustí S. The oligotrophic ocean is heterotrophic. ANNUAL REVIEW OF MARINE SCIENCE 2012; 5:551-569. [PMID: 22809189 DOI: 10.1146/annurev-marine-121211-172337] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Incubation (in vitro) and incubation-free (in situ) methods, each with their own advantages and limitations, have been used to derive estimates of net community metabolism in the oligotrophic subtropical gyres of the open ocean. The hypothesis that heterotrophic communities are prevalent in most oligotrophic regions is consistent with the available evidence and supported by scaling relationships showing that heterotrophic communities prevail in areas of low gross primary production, low chlorophyll a, and warm water, conditions found in the oligotrophic ocean. Heterotrophic metabolism can prevail where heterotrophic activity is subsidized by organic carbon inputs from the continental shelf or the atmosphere and from nonphotosynthetic autotrophic and mixotrophic metabolic pathways. The growth of the oligotrophic regions is likely to be tilting the metabolic balance of the ocean toward a greater prevalence of heterotrophic communities.
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Affiliation(s)
- Carlos M Duarte
- Department of Global Change Research, Mediterranean Institute of Advanced Studies, Esporles, Spain.
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18
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Hu C, Lee Z, Franz B. Chlorophyll a
algorithms for oligotrophic oceans: A novel approach based on three-band reflectance difference. ACTA ACUST UNITED AC 2012. [DOI: 10.1029/2011jc007395] [Citation(s) in RCA: 448] [Impact Index Per Article: 37.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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19
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Doney SC, Ruckelshaus M, Duffy JE, Barry JP, Chan F, English CA, Galindo HM, Grebmeier JM, Hollowed AB, Knowlton N, Polovina J, Rabalais NN, Sydeman WJ, Talley LD. Climate change impacts on marine ecosystems. ANNUAL REVIEW OF MARINE SCIENCE 2012; 4:11-37. [PMID: 22457967 DOI: 10.1146/annurev-marine-041911-111611] [Citation(s) in RCA: 842] [Impact Index Per Article: 70.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
In marine ecosystems, rising atmospheric CO2 and climate change are associated with concurrent shifts in temperature, circulation, stratification, nutrient input, oxygen content, and ocean acidification, with potentially wide-ranging biological effects. Population-level shifts are occurring because of physiological intolerance to new environments, altered dispersal patterns, and changes in species interactions. Together with local climate-driven invasion and extinction, these processes result in altered community structure and diversity, including possible emergence of novel ecosystems. Impacts are particularly striking for the poles and the tropics, because of the sensitivity of polar ecosystems to sea-ice retreat and poleward species migrations as well as the sensitivity of coral-algal symbiosis to minor increases in temperature. Midlatitude upwelling systems, like the California Current, exhibit strong linkages between climate and species distributions, phenology, and demography. Aggregated effects may modify energy and material flows as well as biogeochemical cycles, eventually impacting the overall ecosystem functioning and services upon which people and societies depend.
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Affiliation(s)
- Scott C Doney
- Marine Chemistry and Geochemistry Department, Woods Hole Oceanographic Institution, Woods Hole, Massachusetts 02543, USA.
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20
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Martinez E, Antoine D, D'Ortenzio F, de Boyer Montégut C. Phytoplankton spring and fall blooms in the North Atlantic in the 1980s and 2000s. ACTA ACUST UNITED AC 2011. [DOI: 10.1029/2010jc006836] [Citation(s) in RCA: 55] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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21
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Park JY, Kug JS, Park J, Yeh SW, Jang CJ. Variability of chlorophyll associated with El Niño–Southern Oscillation and its possible biological feedback in the equatorial Pacific. ACTA ACUST UNITED AC 2011. [DOI: 10.1029/2011jc007056] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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22
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Álvarez M, Tanhua T, Brix H, Lo Monaco C, Metzl N, McDonagh EL, Bryden HL. Decadal biogeochemical changes in the subtropical Indian Ocean associated with Subantarctic Mode Water. ACTA ACUST UNITED AC 2011. [DOI: 10.1029/2010jc006475] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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23
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McQuatters-Gollop A, Reid PC, Edwards M, Burkill PH, Castellani C, Batten S, Gieskes W, Beare D, Bidigare RR, Head E, Johnson R, Kahru M, Koslow JA, Pena A. Is there a decline in marine phytoplankton? Nature 2011; 472:E6-7; discussion E8-9. [PMID: 21490625 DOI: 10.1038/nature09950] [Citation(s) in RCA: 90] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2010] [Accepted: 02/01/2011] [Indexed: 11/09/2022]
Affiliation(s)
- Abigail McQuatters-Gollop
- Sir Alister Hardy Foundation for Ocean Science, The Laboratory, Citadel Hill, Plymouth, PL1 2PB, UK.
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24
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Mouw CB, Yoder JA. Optical determination of phytoplankton size composition from global SeaWiFS imagery. ACTA ACUST UNITED AC 2010. [DOI: 10.1029/2010jc006337] [Citation(s) in RCA: 63] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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25
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Perspectives on empirical approaches for ocean color remote sensing of chlorophyll in a changing climate. Proc Natl Acad Sci U S A 2010; 107:17073-8. [PMID: 20861445 DOI: 10.1073/pnas.0913800107] [Citation(s) in RCA: 122] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Phytoplankton biomass and productivity have been continuously monitored from ocean color satellites for over a decade. Yet, the most widely used empirical approach for estimating chlorophyll a (Chl) from satellites can be in error by a factor of 5 or more. Such variability is due to differences in absorption and backscattering properties of phytoplankton and related concentrations of colored-dissolved organic matter (CDOM) and minerals. The empirical algorithms have built-in assumptions that follow the basic precept of biological oceanography--namely, oligotrophic regions with low phytoplankton biomass are populated with small phytoplankton, whereas more productive regions contain larger bloom-forming phytoplankton. With a changing world ocean, phytoplankton composition may shift in response to altered environmental forcing, and CDOM and mineral concentrations may become uncoupled from phytoplankton stocks, creating further uncertainty and error in the empirical approaches. Hence, caution is warranted when using empirically derived Chl to infer climate-related changes in ocean biology. The Southern Ocean is already experiencing climatic shifts and shows substantial errors in satellite-derived Chl for different phytoplankton assemblages. Accurate global assessments of phytoplankton will require improved technology and modeling, enhanced field observations, and ongoing validation of our "eyes in space."
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26
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Boyce DG, Lewis MR, Worm B. Global phytoplankton decline over the past century. Nature 2010; 466:591-6. [PMID: 20671703 DOI: 10.1038/nature09268] [Citation(s) in RCA: 329] [Impact Index Per Article: 23.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2010] [Accepted: 06/09/2010] [Indexed: 11/09/2022]
Abstract
In the oceans, ubiquitous microscopic phototrophs (phytoplankton) account for approximately half the production of organic matter on Earth. Analyses of satellite-derived phytoplankton concentration (available since 1979) have suggested decadal-scale fluctuations linked to climate forcing, but the length of this record is insufficient to resolve longer-term trends. Here we combine available ocean transparency measurements and in situ chlorophyll observations to estimate the time dependence of phytoplankton biomass at local, regional and global scales since 1899. We observe declines in eight out of ten ocean regions, and estimate a global rate of decline of approximately 1% of the global median per year. Our analyses further reveal interannual to decadal phytoplankton fluctuations superimposed on long-term trends. These fluctuations are strongly correlated with basin-scale climate indices, whereas long-term declining trends are related to increasing sea surface temperatures. We conclude that global phytoplankton concentration has declined over the past century; this decline will need to be considered in future studies of marine ecosystems, geochemical cycling, ocean circulation and fisheries.
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Affiliation(s)
- Daniel G Boyce
- Biology Department, Dalhousie University, Halifax, Nova Scotia, Canada, B3H 4J1.
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27
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Lee Z, Shang S, Hu C, Lewis M, Arnone R, Li Y, Lubac B. Time series of bio-optical properties in a subtropical gyre: Implications for the evaluation of interannual trends of biogeochemical properties. ACTA ACUST UNITED AC 2010. [DOI: 10.1029/2009jc005865] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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28
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Martinez E, Antoine D, D’Ortenzio F, Gentili B. Climate-Driven Basin-Scale Decadal Oscillations of Oceanic Phytoplankton. Science 2009; 326:1253-6. [PMID: 19965473 DOI: 10.1126/science.1177012] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Affiliation(s)
- Elodie Martinez
- UPMC University of Paris 06, UMR 7093, Laboratoire d’Océanographie de Villefranche (LOV), 06230 Villefranche-sur-Mer, France; and CNRS, UMR 7093, LOV, 06230 Villefranche-sur-Mer, France
| | - David Antoine
- UPMC University of Paris 06, UMR 7093, Laboratoire d’Océanographie de Villefranche (LOV), 06230 Villefranche-sur-Mer, France; and CNRS, UMR 7093, LOV, 06230 Villefranche-sur-Mer, France
| | - Fabrizio D’Ortenzio
- UPMC University of Paris 06, UMR 7093, Laboratoire d’Océanographie de Villefranche (LOV), 06230 Villefranche-sur-Mer, France; and CNRS, UMR 7093, LOV, 06230 Villefranche-sur-Mer, France
| | - Bernard Gentili
- UPMC University of Paris 06, UMR 7093, Laboratoire d’Océanographie de Villefranche (LOV), 06230 Villefranche-sur-Mer, France; and CNRS, UMR 7093, LOV, 06230 Villefranche-sur-Mer, France
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Abstract
After the successful Coastal Zone Color Scanner (CZCS, 1978-1986) demonstration that quantitative estimations of geophysical variables such as chlorophyll a and diffuse attenuation coefficient could be derived from top of the atmosphere radiances, a number of international missions with ocean color capabilities were launched beginning in the late 1990s. Most notable were those with global data acquisition capabilities, i.e., the Ocean Color and Temperature Sensor (OCTS,Japan, 1996-1997), the Sea-viewing Wide Field-of-view Sensor (SeaWiFS, United States, 1997-present), two Moderate Resolution Imaging Spectroradiometers (MODIS, United States, Terra/2000-present and Aqua/2002-present), the Global Imager (GLI, Japan, 2002-2003), and the Medium Resolution Imaging Spectrometer (MERIS, European Space Agency, 2002-present). These missions have provided data of exceptional quality and continuity, allowing for scientific inquiries into a wide variety of marine research topics not possible with the CZCS. This review focuses on the scientific advances made over the past decade using these data sets.
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Affiliation(s)
- Charles R McClain
- Oceans Branch, NASA Goddard Space Flight Center, Greenbelt, Maryland 20771, USA.
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30
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Friend AD, Geider RJ, Behrenfeld MJ, Still CJ. Photosynthesis in Global-Scale Models. PHOTOSYNTHESIS IN SILICO 2009. [DOI: 10.1007/978-1-4020-9237-4_20] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/02/2022]
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31
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Irwin AJ, Finkel ZV. Mining a sea of data: deducing the environmental controls of ocean chlorophyll. PLoS One 2008; 3:e3836. [PMID: 19043583 PMCID: PMC2584232 DOI: 10.1371/journal.pone.0003836] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2008] [Accepted: 11/03/2008] [Indexed: 11/18/2022] Open
Abstract
Chlorophyll biomass in the surface ocean is regulated by a complex interaction of physiological, oceanographic, and ecological factors and in turn regulates the rates of primary production and export of organic carbon to the deep ocean. Mechanistic models of phytoplankton responses to climate change require the parameterization of many processes of which we have limited knowledge. We develop a statistical approach to estimate the response of remote-sensed ocean chlorophyll to a variety of physical and chemical variables. Irradiance over the mixed layer depth, surface nitrate, sea-surface temperature, and latitude and longitude together can predict 83% of the variation in log chlorophyll in the North Atlantic. Light and nitrate regulate biomass through an empirically determined minimum function explaining nearly 50% of the variation in log chlorophyll by themselves and confirming that either light or macronutrients are often limiting and that much of the variation in chlorophyll concentration is determined by bottom-up mechanisms. Assuming the dynamics of the future ocean are governed by the same processes at work today, we should be able to apply these response functions to future climate change scenarios, with changes in temperature, nutrient distributions, irradiance, and ocean physics.
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Affiliation(s)
- Andrew J Irwin
- Department of Mathematics & Computer Science, Mount Allison University, Sackville, New Brunswick, Canada.
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32
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Lee Z, Weidemann A, Kindle J, Arnone R, Carder KL, Davis C. Euphotic zone depth: Its derivation and implication to ocean-color remote sensing. ACTA ACUST UNITED AC 2007. [DOI: 10.1029/2006jc003802] [Citation(s) in RCA: 162] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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33
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Uitz J, Claustre H, Morel A, Hooker SB. Vertical distribution of phytoplankton communities in open ocean: An assessment based on surface chlorophyll. ACTA ACUST UNITED AC 2006. [DOI: 10.1029/2005jc003207] [Citation(s) in RCA: 531] [Impact Index Per Article: 29.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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