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Registros recuperados: 11
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A Statistical Algorithm for Estimating Chlorophyll Concentration in the New Caledonian Lagoon ArchiMer
Wattelez, Guillaume; Dupouy, Cecile; Mangeas, Morgan; Lefevre, Jerome; Touraivane,; Frouin, Robert.
Spatial and temporal dynamics of phytoplankton biomass and water turbidity can provide crucial information about the function, health and vulnerability of lagoon ecosystems (coral reefs, sea grasses, etc.). A statistical algorithm is proposed to estimate chlorophyll-a concentration ([chl-a]) in optically complex waters of the New Caledonian lagoon from MODIS-derived remote-sensing reflectance (R-rs). The algorithm is developed via supervised learning on match-ups gathered from 2002 to 2010. The best performance is obtained by combining two models, selected according to the ratio of R-rs in spectral bands centered on 488 and 555 nm: a log-linear model for low [chl-a] (AFLC) and a support vector machine (SVM) model or a classic model (OC3) for high [chl-a]....
Tipo: Text Palavras-chave: Chlorophyll-a concentration; MODerate resolution Imaging Spectroradiometer (MODIS); Ocean color; Remote sensing; Statistical algorithm; Oligotrophic waters; New Caledonia; Coral lagoon.
Ano: 2016 URL: https://archimer.ifremer.fr/doc/00481/59309/62060.pdf
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ANALYSIS OF SPACE-TIME VARIABILITY OF THE PLATA RIVER PLUME Gayana
Piola,Alberto R.; Romero,Silvia I..
Satellite ocean colour data from the Sea-Viewing Wide Field-of-View Sensor are analyzed to monitor the space-time variability of the Plata river plume over the continental shelf and slope. SeaWiFS Chlorophyll-a (CSAT) product is used to understand the nature of changes in the colour of waters and how this relates to variations in wind direction and river outflow. We use a 5-year data set (1998-2002) of Global Area Coverage monthly mean composites. The analysis of CSAT data reveals strong seasonal variability over the continental shelf with maximum northeastward penetrations in the austral winter (June to August). The plume may reach ~27S, about 1000 km northeast of the Plata estuary. In summer the plume is confined to south of 32°S and the Plata...
Tipo: Journal article Palavras-chave: Ocean color; River plumes; Plata plume; SeaWiFS.
Ano: 2004 URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-65382004000300030
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Apports des données de la 'couleur de l'eau' à la modélisation couplée physique-biogéochimie en milieu dynamique côtier : Application au Rio de la Plata et au Golfe de Gascogne ArchiMer
Huret, Martin.
Continental margins play a crucial role in biogeochemical fluxes between the continents and the open ocean. They are also highly sensitive to human perturbations. Primary production is highly dependent on the complex dynamics of these coastal zones, and on the river supply in nutrients, as well as in Suspended Particulate Matter (SPM) which limit light availability. The quantification of the production is a prerequisite in many applications, from the understanding of the role of the coastal ocean in climate change, to eutrophication and fisheries resources issues within the frame of the integrated management of the coastal zone. Coupled physical-biogeochemical models are useful in studying and monitoring primary production. Because of the numerous complex...
Tipo: Text Palavras-chave: Parameter estimation; Data assimilation; Suspended Particulate Matter (SPM); Chlorophyll a; Phytoplankton blooms; Physical biogeochemical coupled model; Ocean color; Satellite data; Coastal area; Bay of Biscay; Rio de la Plata; Estimation de paramètres; Assimilation de données; Matières En Suspension (MES); Chlorophylle a; Blooms phytoplanctoniques; Modèle couplé physique biogéochimie; Couleur de l'eau; Donnée satellitale; Milieu côtier; Golfe de Gascogne; Rio de la Plata.
Ano: 2005 URL: http://archimer.ifremer.fr/doc/2005/these-337.pdf
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Comparison of spaceborne measurements of sea surface salinity and colored detrital matter in the Amazon plume ArchiMer
Fournier, Severine; Chapron, Bertrand; Salisbury, J.; Vandemark, Douglas; Reul, Nicolas.
Large rivers are key hydrologic components in oceanography, particularly regarding air-sea and land-sea exchanges and biogeochemistry. We enter now in a new era of Sea Surface Salinity (SSS) observing system from Space with the recent launches of the ESA Soil Moisture and Ocean Salinity (SMOS) and the NASA Aquarius/Sac-D missions. With these new sensors, we are now in an excellent position to revisit SSS and ocean color investigations in the tropical northwest Atlantic using multi-year remote sensing time series and concurrent in situ observations. The Amazon is the world's largest river in terms of discharge. In its plume, SSS and upper water column optical properties such as the absorption coefficient of colored detrital matter (acdm) are strongly...
Tipo: Text Palavras-chave: Amazon-Orinoco river plume; SMOS SSS; Conservative mixing; Ocean color; Salinity; Satellite oceanography.
Ano: 2015 URL: http://archimer.ifremer.fr/doc/00255/36610/35742.pdf
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Development of a Semi-Analytical Algorithm for the Retrieval of Suspended Particulate Matter from Remote Sensing over Clear to Very Turbid Waters ArchiMer
Han, Bing; Loisel, Hubert; Vantrepotte, Vincent; Meriaux, Xavier; Bryere, Philippe; Ouillon, Sylvain; Dessailly, David; Xing, Qianguo; Zhu, Jianhua.
Remote sensing of suspended particulate matter, SPM, from space has long been used to assess its spatio-temporal variability in various coastal areas. The associated algorithms were generally site specific or developed over a relatively narrow range of concentration, which make them inappropriate for global applications (or at least over broad SPM range). In the frame of the GlobCoast project, a large in situ data set of SPM and remote sensing reflectance, R-rs(lambda), has been built gathering together measurements from various coastal areas around Europe, French Guiana, North Canada, Vietnam, and China. This data set covers various contrasting coastal environments diversely affected by different biogeochemical and physical processes such as sediment...
Tipo: Text Palavras-chave: Specific backscattering coefficient; Empirical algorithm; Semi-analytic algorithm; Coastal waters; Suspended particulate matter; Ocean color.
Ano: 2016 URL: https://archimer.ifremer.fr/doc/00589/70062/68010.pdf
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Estimation of the diffuse attenuation coefficient K-dPAR using MERIS and application to seabed habitat mapping ArchiMer
Saulquin, Bertrand; Hamdi, Anouar; Gohin, Francis; Populus, Jacques; Mangin, Antoine; D'Andon, Odile Fanton.
The availability of light in the water column and at the seabed determines the euphotic zone and constrains the type and the vertical distribution of algae species. Light attenuation is traditionally quantified as the diffuse attenuation coefficient of the downwelling spectral irradiance atwavelength 490 nm(Kd490) or the photosynthetically available radiation (KdPAR). Satellite observations provide global coverage of these parameters at high spatial and temporal resolution and several empirical and semi-analytical models are commonly used to derive Kd490 and KdPAR maps from ocean colour satellite sensors. Most of these existing empirical or semi-analytical models have been calibrated in open ocean waters and performwell in these regions, but tend to...
Tipo: Text Palavras-chave: Ocean color; Light attenuation; Photosynthetic available radiation; Euphotic depth; Seabed mapping.
Ano: 2013 URL: http://archimer.ifremer.fr/doc/00117/22831/21496.pdf
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Fusion of Sun-Synchronous and Geostationary Images for Coastal and Ocean Color Survey Application to OLCI (Sentinel-3) and FCI (MTG) ArchiMer
Peschoud, Cecile; Minghelli, Audrey; Mathieu, Sandrine; Lei, Manchun; Pairaud, Ivane; Pinazo, Christel.
Open ocean and coastal area monitoring requires multispectral satellite images with a middle spatial resolution ({\sim !300 {text{m}}}) and a high temporal repeatability ({\sim !1 {text{h}}}) . As no current satellite sensors have such features, the aim of this study is to propose a fusion method to merge images delivered by a low earth orbit (LEO) sensor with images delivered by a geostationary earth orbit (GEO) sensor. This fusion method, called spatial spectral temporal fusion (SSTF), is applied to the future sensors—Ocean and Land Color Instrument (OLCI) (on Sentinel-3) and Flexible Combined Imager (FCI) (on Meteosat Third Generation) whose images were simulated. The OLCI bands, acquired at t _{0} , are divided by the oversampled corresponding FCI band...
Tipo: Text Palavras-chave: Fusion; Image simulation; Meteosat Third Generation (MTG); Ocean color; Ocean and Land Color Instrument.
Ano: 2017 URL: https://archimer.ifremer.fr/doc/00343/45413/49041.pdf
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Geostationary Image Simulation on Coastal Waters Using Hydrodynamic Biogeochemical and Sedimentary Coupled Models ArchiMer
Lei, Manchun; Minghelli, Audrey; Fraysse, Marion; Pairaud, Ivane; Verney, Romaric; Pinazo, Christel.
This study proposes a method to simulate the images of the future European geostationary sensor dedicated to ocean color sensor: the geostationary ocean color advanced permanent imager (GeoOCAPI), and it demonstrates the sensor capabilities to monitor the water composition throughout the day. The temporal variation of the coastal seascape is obtained from biogeochemical and hydrosedimentary models, the ocean-atmosphere radiance is obtained from the water and atmosphere radiative transfer model. The GeoOCAPI images are simulated with 400-m resolution, 18 spectral bands with associated signal-to-noise ratio (SNR) and with 1-h acquisition frequency, on the Gulf of Lion (Marseille, France) during a pollution event caused by the urban outfall of Cortiou in...
Tipo: Text Palavras-chave: Geostationary ocean color advanced permanent imager (GeoOCAPI); Geostationary orbit; Image simulation; Ocean color.
Ano: 2016 URL: http://archimer.ifremer.fr/doc/00363/47462/50154.pdf
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MULTISPECTRAL TRACKING OF PHYTOPLANKTON IN THE COLOMBIAN CARIBBEAN Gayana
Ojeda Caicedo,V. V.; Plata Gómez,A..
In a quantitative research study, the concentration and circulation of group of micro-organisms "phytoplankton" have been found trough the images of the ocean colour in the Colombian Caribbean Sea. These images have been observed trough the Sea Star satellite. The method logical procedure was to collect a number of ocean images at the 1A level of the sensor SeaWifs. This only covered the geographical area of study and the seasons of the year. The selection criterion was to give priority to the absence of clouds in the area. Afterwards, the images were analyzed to create mosaics in convenient periods of the to, in turn visualize the periodical changes of the micro-organisms. Thus place with higher concentration of phytoplankton in the study site were...
Tipo: Journal article Palavras-chave: Ocean color; Primary production; SeaWifs; SeaDas.
Ano: 2004 URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-65382004000300024
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ProVal: A New Autonomous Profiling Float for High Quality Radiometric Measurements ArchiMer
Leymarie, Edouard; Penkerc'H, Christophe; Vellucci, Vincenzo; Lerebourg, Christophe; Antoine, David; Boss, Emmanuel; Lewis, Marion R.; D'Ortenzio, Fabrizio; Claustre, Herve.
An efficient system to produce in situ high quality radiometric measurements is compulsory to rigorously perform the vicarious calibration of satellite sensors dedicated to Ocean Color Radiometry (OCR) and to validate their derived products. This requirement is especially needed during the early stages of an OCR satellite activity or for remote areas poorly covered by oceanographic cruises with possible bio-optical anomalies. Taking advantage of Argo's profiling float technology, we present a new autonomous profiling float dedicated to in situ radiometric measurements. The float is based on the Provor CTS5 (manufacturer NKE) with an added novel two protruding arm design allowing for sensor redundancies, shading mitigation and near-surface data. Equipped...
Tipo: Text Palavras-chave: Autonomous profiling floats; Remote sensing reflectance; Ocean color; Validation; System vicarious calibration; Austral ocean; Mediterranean Sea; Radiometric measurement.
Ano: 2018 URL: https://archimer.ifremer.fr/doc/00585/69694/67579.pdf
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Satellite-derived parameters for biological modelling in coastal waters: Illustration over the eastern continental shelf of the Bay of Biscay ArchiMer
Gohin, Francis; Loyer, S; Lunven, Michel; Labry, Claire; Froidefond, J; Delmas, Daniel; Huret, Martin; Herbland, Alain.
In biological modelling of the coastal phytoplankton dynamics, the light attenuation coefficient is often expressed as a function of the concentrations of chlorophyll and mineral suspended particulate matter (SPM). In order to estimate the relationship between these parameters over the continental shelf of the northern Bay of Biscay, a set of in situ data has been gathered for the period 1998-2003 when SeaWiFS imagery is available. These data comprise surface measurements of the concentrations of total SPM, chlorophyll, and irradiance profiles from which is derived the attenuation coefficient of the photosynthetically available radiation, K-PAR. The performance of the IFREMER look-up table used to retrieve the chlorophyll concentration from the SeaWiFS...
Tipo: Text Palavras-chave: Bay of Biscay; SeaWiFS; Sediment; Chlorophyll; Ocean color.
Ano: 2005 URL: http://archimer.ifremer.fr/doc/2005/publication-1172.pdf
Registros recuperados: 11
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