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Fluorescence

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  • This dataset provides a global Look-Up Table (LUT) of physiological ratios for the real-time adjustment of chlorophyll-a fluorescence measured by biogeochemical Argo (BGC-Argo) profiling floats. The physiological ratios aim to account for the global variability in the relationship between fluorescence and chlorophyll-a concentration, as influenced by phytoplankton physiology. The LUT was developed using two different gap-filled observational Argo-based products (SOCA machine learning-based methodology ; Sauzède et al., 2016; Sauzède et al., 2024). The first product provides gap-filled chlorophyll-a data derived from fluorescence corrected for dark signal and non-photochemical quenching (NPQ) following Schmechtig et al. (2023), while the second product provides chlorophyll-a concentrations derived from light attenuation. The latter is based on the downward irradiance at 490 nm (ED490) derived from the SOCA-light method (Renosh et al., 2023). From this, the diffuse attenuation coefficient (KD490) is computed, which is subsequently used to estimate the chlorophyll-a concentration through the bio-optical relationships described by Morel et al. (2007). These two products, based on fluorescence and radiometry, enable the derivation of spatially varying correction factors, or physiological ratios. These ratios provide a validated grounded framework for adjusting real-time fluorescence observations from OneArgo floats into chlorophyll-a concentrations. The LUT is distributed in NetCDF format and is provided on a regular 1°×1° latitude–longitude grid covering the global ocean. Each grid cell contains the temporal mean, averaged over the water column (from the surface to 1.5 times the euphotic depth), of the physiological ratio. The file also includes metadata describing variable definitions, units, and other relevant information. Variables included: - physiological_ratio — fluorescence-to-radiometry-based chlorophyll correction factor (dimensionless) - physiological_ratio_sd — temporal standard deviation (over the twelve months) of the fluorescence-to-radiometry-based chlorophyll correction factor (dimensionless) - lat, lon — spatial coordinates (degrees north/east) - Global attributes — dataset description, reference citation, and contact information

  • This In Situ delayed mode product integrates the best available version of in situ oxygen, chlorophyll / fluorescence and nutrients data. The latest version of Copernicus delayed-mode BGC (bio-geo-chemical) product is also distributed from Copernicus Marine catalogue.

  • As part of the marine water quality monitoring of the “Pertuis” and the “baie de l’Aiguillon” (France), commissioned by the OFB and carried out by setec énergie environnement, three monitoring stations were installed. Two of them were set up at the mouths of the Charente and Seudre rivers on February 6 and 27, 2019, respectively, while a third was deployed in the Bay of Aiguillon on March 24, 2021. The dataset presented here concerns the station installed in the Bay of Aiguillon. Measurements are organized into .csv files, with one file per year. Data is collected using a WiMO multiparameter probe, which records the following parameters: •    Temperature (-2 to 35 °C) •    Conductivity (0 to 100 mS/cm) •    Pressure (0 to 30 m) •    Turbidity (0 to 4000 NTU) •    Dissolved Oxygen (0 to 23 mg/L & 0 to 250 %) •    Fluorescence (0 to 500 ppb)  

  • As part of the marine water quality monitoring of the “Pertuis” and the “baie de l’Aiguillon” (France), commissioned by the OFB and carried out by setec énergie environnement, three monitoring stations were installed. Two of them were set up at the mouths of the Charente and Seudre rivers on February 6 and 27, 2019, respectively, while a third was deployed in the Bay of Aiguillon on March 24, 2021. The dataset presented here concerns the station installed in the Charente estuary. Measurements are organized into .csv files, with one file per year. Data is collected using a SAMBAT multiparameter probe, which records the following parameters: - Temperature (-5 to 35 °C) - Conductivity (0 to 10 mS/cm) - Pressure (0 to 10 m) - Turbidity (0 to 300 NTU) - Dissolved Oxygen (0 to 20 mg/L & 0 to 200 %) - Fluorescence (0 to 50 µg/l) - PH (0/14)

  • This dataset contains bin-averaged optical particle measurements from Biogeochemical Argo floats. Full description of data and methodology is contained in the manuscript submitted to Science entitled "Particle fragmentation exerts strong control on biological sequestration of CO2 by the oceans". Optical measurements are particulate backscattering and chlorophyll fluorescence, and each have been partitioned into large (>100 µm) and small (<100 µm) size classes for use in estimating the rate of fragmentation of large, sinking partiles. The data cover 34 high-latitude open-ocean mesopelagic sinking particle plumes in the supolar North Atlantic and the Southern Ocean observed at 1 m vertical resolution and 2-5 day temporal resolution by profiling floats over a 30-day period. Each 30-day period is divided into five temporal bins of six days each. Vertical binning is at 50-meter intervals from the 250-950 m.

  • Physical data associated with the ABRACO cruise. The ABRACOS (Acoustics along the BRAzilian COaSt) cruise aims to begin an integrated approach to monitoring the tropical marine ecosystems in the Brazilian Nordeste region in order to better understand the connectivity between the sub-systems composing it. In particular, this cruise should fill this gap and improve understanding of the degree of connectivity which exists between the oceanic islands and the continental margin in the Nordeste of Brazil, as well as within the continental platform. In this context, the main objective of the ABRACOS cruise consisted in drawing up a 3D characterization of abiotic and biotic compartments and their interactions in the Brazilian Nordeste. Specific objectives: Objective 1 - Characterization of island and coastal dynamics. Measurement of hydrological characteristics and currents (rosette, CTD, ADCP) should enable the circulation and characteristics of water masses to be described. These data will be more specifically used to study the physical connections between 1) the oceanic islands and coastal ecosystems and 2) the coast along the ocean and coastal zones. The in-situ measurements obtained will also be used to validate high resolution regional hydrodynamic models (e.g. ROMS model) which will be implemented. In-situ data acquired during the ABRACOS cruise will be supplemented by satellite data for sea surface heights (e.g. AVISO), surface temperature and chlorophyll (e.g. MODIS) and wind (e.g. ASCAT). However, it should be noted that the resolution of the products usually used and land-ocean interferences on altimetry and backscatter data will not allow these products to be used at less than 30-50 km from the coast. We will be able to partially eliminate this problem by using new "alongtrack" processing of altimetric data performed by the Center for Topographic studies of the Ocean and Hydrosphere in Toulouse. These data will be used to document the geostrophic (from sea level) ageostrophic (from wind) components of surface circulation and their variability in coastal zones. Objective 2 - Ecosystem acoustics. Acoustic tools can provide the simultaneous acquisition of quantitative and qualitative data, at different spatial-temporal scales, in numerous biotic and abiotic compartments of an ecosystem. These data can be used to characterize the ecosystem in three dimensions and directly study interactions between compartments. Active acoustics have rarely been used in tropical coastal zones. The multifrequency (38, 70, 120, and 200 kHz) acoustic data acquired during the ABRACOS cruise will be used to create an initial 3D characterization of island and coastal ecosystems in the Brazilian Nordeste region, simultaneously characterizing the seabed and water column, when possible. The French team proposing this has sound experience in the field and developed the open source 'Echopen' software in Brest (www.france-nord.ird.fr/lesressources/outils-informatiques) which can separate the various sources of acoustic echoes (e.g. zooplankton, gelatinous organisms and fish) from multifrequency acoustic data. In order to calibrate the 'Echopen Brésil' version, acoustic observations from the ABRACOS cruise must be combined with sampling using micronekton, mesopelagic and bottom trawls (Leg 2 only) and sampling of zooplankton at fixed stations (bongo and WP2 plankton nets and phytoplankton nets). To validate the 'Echopen substrat' tool we will use sampling done with bottom trawl, substrate grab and video camera observations. Objective 3 - Biodiversity and trophic structure. As indicated, acoustic observations will be complemented by in-situ sampling of planktonic, pelagic (mid-water trawls) and demersal-benthic (bottom trawl) organisms. This will involve establishing how hydrological conditions determine the vertical distribution of organisms and therefore interactions. One part of the sampled organisms will be conserved in formaldehyde then identified by taxonomists at the Federal university of Rio de Janeiro (UFRJ) to be added to Brazilian collections. The remainder of the samples will be used to obtain biological information. Along with the classic biological measurements (size, weight, sex, maturity, etc.) specimens of entire organisms (plankton) and soft tissues (muscles) will be taken in order to titrate various trophic tracers: stable isotopes of carbon, nitrogen and insofar as possible mercury. In addition, particulate organic matter (POM) will be collected by filtration (samples taken by rosette) to titrate the amounts of stable isotopes. Spatial variations in these tracers will make it possible to highlight the relative positions of these organisms in the food web and variations in food sources through the local POM signatures. Measurements of methylmercury (MeHg), a neurotoxin which accumulates in the food chain, will also be performed on part of the samples used for stable isotopes. The related projects are ABRACOS and Action Incitative IRD "DANOB".

  • Physical data associated with the AMAZOMIX cruise. The Amazon shelf encompasses a variety of physical processes, such as fluvial inputs, coastal currents, mesoscale, filaments, tides, internal waves and upwelling, influencing nutrient concentrations, chlorophyll and suspended matter. They also affect energy, salt and heat balances; parameters that condition physical/biogeochemical interactions and ecosystem functioning, from bacteria to plankton to fish resources. In particular, internal tidal waves are very energetic in this region. They impact biogeochemical cycles via the vertical mixture induced by their dissipation or vertical movements induced by their propagation. They thus allow a significant input of nutriments into the euphotic layer enhancing primary production, as observed on the surface from watercolour data. Internal tidal waves could thus influence the biological pump and the carbon cycle. In addition, overall marine biodiversity of the region, from bacteria to fish is not well described. The connectivity of species in the tropical Atlantic is also still an open question. The Caribbean region is by far more bio-diverse than the Brazilian one. One of the hypotheses is that the Amazon plume, which can extend up to 3,000 km off the mouth, would constitute a barrier for some organisms. The Amazon Shelf is thus an ideal experimental laboratory to study the impact of physical processes on the structure and function of neritic and oceanic marine ecosystems. In this context, the objective of the multidisciplinary AMAZOMIX survey was to study the impact of the Amazon River plume, internal tides and associated turbulent mixing, on marine ecosystem in contrasting regions off the Amazon shelf. For that purpose, the multidisciplinary AMAZOMIX project brings together physicists, biogeochemists, bioopticians and biologists. The sampling strategy consists in the simultaneous acquisition of a comprehensive set of environmental and biological compartments, including micro-organisms (bacteria, phyto and zooplankton) and higher trophic levels (micronekton, demersal and pelagic fish). AMAZOMIX is the first campaign to develop this multi-disciplinary approach off the Amazon shelf. In situ results will be analysed in interaction with digital tools and data, modelling (1/36°, with and without tides, 1/12° coupled) and satellite data analyses. This dataset contains the AMAZOMIX 2021 qualified measurements of  - The hydrographic CTD-02 (netCDF and csv text files) - Ship Acoustic Doppler Current Profilers (OS 75 kHz, netCDF and csv text files) - Lowered Acoustic Doppler Current Profilers (WH300 downlooking and WH300 uplooking, netCDF and csv text files) - Thermosalinometer (netCDF and csv text files) - Vertical microstructure profile (VMP-250, binary file)  

  • There are at least a dozen small hyper-turbid estuaries facing the Bay of Biscay, geographically situated between the two major estuaries of the Gironde and the Loire. MAGEST and SYVEL high-frequency multi-site monitoring revealed that the Loire, and to a lesser extent the Gironde, are subject to summer hypoxia. These observations raised the question of the potential occurrence of hypoxia in the small estuaries in between, motivating an investigation of dissolved oxygen in one of them, the Charente estuary. Oxygen and salinity sensors were placed at L'Houmée (2019), Tonnay-Charente (2018; 2019), Rochefort (2020; 2021; 2022), Martrou (2020) during summer, the most critical period for dissolved oxygen; a multiparameter probe was placed at Tonnay-Charente from April to November 2020. Longitudinal investigations along the estuary axis were also carried out during the summers of 2018 and 2019. All the measurements were acquired at 0.5 ± 0.2 meters below the surface. The dataset enabled us to identify the occurrence of summer hypoxia and an oxygen depletion zone in the Charente estuary. These results resulted in the implementation of high-frequency monitoring at Tonnay-Charente, operational since November 2020.

  • Percentile 90 calculé sur la période productive au sens DCE (mars-octobre) 2003-2009, à partir des Chl-a MODIS traitées par l'algorithme Ifremer OC5.

  • The COAST-HF/Arcachon-Ferret time series characterizes the hydrology of the interface between the Arcachon lagoon, located in the South-Western France, and the Atlantic Ocean. A buoy belonging to Phares et Balises is instrumented with a multi-parametric probe that records sub-surface temperature, conductivity, depth, turbidity and fluorescence every 10 minutes since February 2018. It is opérated by the OASU and EPOC teams (Univ. Bordeaux/CNRS). COAST-HF (Coastal OceAn observing SysTem - High Frequency; www.coast-hf.fr) is a national observation network accredited by the CNRS as a national Earth Science Observatory (Service National d’Observation: SNO). It aims to federate and coordinate a set of 14 fixed platforms instrumented with high-frequency in situ measurements for key parameters of coastal waters. The COAST-HF/Arcachon-Ferret buoy is one of them. COAST-HF is part of the French Research Infrastructure dedicated to coastal ocean observations (RI ILICO, https://www.ir-ilico.fr). Data are transmitted to the Coriolis Côtier database (https://data.coriolis-cotier.org/). Data are raw data.