Data Access Form

Dataset Title:	Northeast Atlantic Ocean, DIVAnd 4D seasonal 6-year average analysis of Water body chlorophyll-a 1971/2024 v2025 [observations]
Institution:	IFREMER, SISMER, Scientific Information Systems for the SEA (Dataset ID: oceanbrowser_opendap_2681_9bfd_a3d9)
Information:	Summary \| License \| Metadata \| Background \| Make a graph

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Dimensions	Start	Stride	Stop	Size	Spacing
observations (count)				1307185	1.0 (even)

Grid Variables (which always also download all of the dimension variables)

obsdepth (depth of the observations, meters)

obslat (latitude of the observations, degrees_north)

obslon (longitude of the observations, degrees_east)

obstime (time of the observations, seconds since 1970-01-01T00:00:00Z)

File type: (more information)

(Documentation / Bypass this form)

(Please be patient. It may take a while to get the data.)

The Dataset Attribute Structure (.das) for this Dataset

Attributes {
  observations {
    Int32 actual_range 0, 1307184;
    String long_name "Observations";
    String units "count";
  }
  obsdepth {
    Float64 colorBarMaximum 8000.0;
    Float64 colorBarMinimum -8000.0;
    String colorBarPalette "TopographyDepth";
    String long_name "depth of the observations";
    String positive "down";
    String standard_name "depth";
    String units "meters";
  }
  obslat {
    Float64 colorBarMaximum 90.0;
    Float64 colorBarMinimum -90.0;
    String long_name "latitude of the observations";
    String standard_name "latitude";
    String units "degrees_north";
  }
  obslon {
    Float64 colorBarMaximum 180.0;
    Float64 colorBarMinimum -180.0;
    String long_name "longitude of the observations";
    String standard_name "longitude";
    String units "degrees_east";
  }
  obstime {
    String ioos_category "Time";
    String long_name "time of the observations";
    String standard_name "time";
    String time_origin "01-JAN-1970 00:00:00";
    String units "seconds since 1970-01-01T00:00:00Z";
  }
  NC_GLOBAL {
    String abstract 
"Moving 6-year analysis of Water body chlorophyll-a in the NorthEast Atlantic for each season:
 - winter: January-March,
 - spring: April-June,
 - summer: July-September,
 - autumn: October-December. 
Every year of the time dimension corresponds to the 6-year centred average of each season. 6-year periods span from 1971/1976 until 2019/2024. Observation data span from 1971 to 2024. 
High-frequency observation trails were filtered to a 3h temporal resolution. 
Depth levels (IODE standard depths): [0.0, 5.0, 10.0, 20.0, 30.0, 40.0, 50.0, 75.0, 100.0, 125.0, 150.0, 200.0, 250.0, 300.0]. 
Data sources: observational data from SeaDataNet/EMODNet Chemistry Data Network. 
Description of DIVAnd analysis: the computation was done with DIVAnd (Data-Interpolating Variational Analysis in n dimensions), version 2.7.12, using GEBCO 30 sec topography for the spatial connectivity of water masses. The horizontal resolution of the produced DIVAnd maps is 0.1 degrees. Horizontal correlation length varies from 200km in open sea regions to 50km at the coast. Vertical correlation length is defined as twice the vertical resolution. Signal-to-noise ratio was fixed to 1 for vertical profiles and 0.1 for time series to account for the redundancy in the time series observations. A logarithmic transformation (DIVAnd.loglin) was applied to the data prior to the analysis. Background field: a vertically-filtered profile of the seasonal data mean value (including all years) is substracted from the data. 
Detrending of data: no, advection constraint applied: no. 
Units: mg/m3.";
    String Acknowledgements "Aggregated data products are generated by EMODnet Chemistry under the support of DG MARE Call for Tenders EASME/2020/OP/0006 (EASME/EMFF/2020/3.1.11/Lot 5/SI2.846161).";
    String area_keywords "Northeast Atlantic Ocean (40W)";
    String area_keywords_urn "SDN:C19::SVX00015";
    String Author_email "Quitterie CAZENAVE <quitterie.cazenave@ifremer.fr> GaÃ«lle HERBERT <gaelle.herbert@ifremer.fr> Julie GATTI <julie.gatti@ifremer.fr>";
    String bathymetry_source "resolution: 0.1Â°, based on the global GEBCO Digital Atlas, 30 sec, 2014";
    String cdm_data_type "Grid";
    String Conventions "CF-1.6, COARDS, ACDD-1.3";
    String creator_name "IFREMER, SISMER, Scientific Information Systems for the SEA";
    String creator_type "institution";
    String creator_url "https://wwz.ifremer.fr/";
    String date "2025-11-03T12:30:11.509";
    String DIVAnd_code_doi "10.5281/zenodo.7016823";
    String DIVAnd_references "Barth, A.; Beckers, J.-M.; Troupin, C.; Alvera-Azcarate, A & Vandenbulcke, L. divand-1.0: n-dimensional variational data analysis for ocean observations. Geoscientific Model Development, 2014, 7, 225-241. DOI: 10.5194/gmd-7-225-2014";
    String DIVAnd_source "https://github.com/gher-uliege/DIVAnd.jl";
    String DIVAnd_version "v2.7.12";
    String doi "https://doi.org/10.13120/7ce735e2-ab22-4f9c-9067-642ec26dd116";
    String file_name "Water_body_chlorophyll-a.4Danl.nc";
    String history 
"Thu Nov  6 16:36:59 2025: ncks -7 -O -L 5 --baa=4 --ppc default=3 /media/ctroupin/T7 Shield/data/EMODnet-Chemistry/Eutrophication2024/Results/By_sea_regions-water_body/Northeast_Atlantic_Ocean/Water_body_chlorophyll-a.4Danl.nc /media/ctroupin/T7 Shield/data/EMODnet-Chemistry/Eutrophication2024/Results/By_sea_regions-water_body/Northeast_Atlantic_Ocean/Water_body_chlorophyll-a.4Danl.nc
2026-03-14T01:19:46Z http://opendap.oceanbrowser.net/thredds/dodsC/data/emodnet-projects/v2025/By_sea_regions-water_body/Northeast_Atlantic_Ocean/Water_body_chlorophyll-a.4Danl.nc
2026-03-14T01:19:46Z https://erddap.emodnet.eu/erddap/griddap/oceanbrowser_opendap_2681_9bfd_a3d9.das";
    String id "DatasetScan/emodnet-projects/v2025/By_sea_regions-water_body/Northeast_Atlantic_Ocean/Water_body_chlorophyll-a.4Danl.nc";
    String infoUrl "http://opendap.oceanbrowser.net/thredds/dodsC/data/emodnet-projects/v2025/By_sea_regions-water_body/Northeast_Atlantic_Ocean/Water_body_chlorophyll-a.4Danl.nc.html";
    String institution "IFREMER, SISMER, Scientific Information Systems for the SEA";
    String institution_urn "SDN:EDMO::486";
    String keywords "6-year, analysis, atlantic, average, body, chla, chlorophyll, chlorophyll-a, data, depth, divand, exchange, exploitation, francais, frequency, HF, high, ifremer, information, institut, international, iode, latitude, longitude, mer, northeast, obsdepth, observations, obslat, obslon, obstime, ocean, oceanographic, pour, recherche, scientific, sea, seasonal, seawater, sismer, systems, time, v2025, water, year";
    String license 
"The data may be used and redistributed for free but is not intended
for legal use, since it may contain inaccuracies. Neither the data
Contributor, ERD, NOAA, nor the United States Government, nor any
of their employees or contractors, makes any warranty, express or
implied, including warranties of merchantability and fitness for a
particular purpose, or assumes any legal liability for the accuracy,
completeness, or usefulness, of this information.";
    String NCO "netCDF Operators version 5.2.1 (Homepage = http://nco.sf.net, Code = https://github.com/nco/nco, Citation = 10.1016/j.envsoft.2008.03.004)";
    String parameter_keyword "Water body chlorophyll-a";
    String parameter_keyword_urn "SDN:P35::EPC00105";
    String product_code "Atlantic-Water_body_chlorophyll-a-v2025-ANA";
    String product_id "7ce735e2-ab22-4f9c-9067-642ec26dd116";
    String product_version "1";
    String project "EMODNET Chemistry â€" Phase 5";
    String search_keywords "Chlorophyll pigment concentrations in water bodies";
    String search_keywords_urn "SDN:P02::CPWC";
    String source "observational data from SeaDataNet/EMODnet Chemistry Data Network";
    String sourceUrl "http://opendap.oceanbrowser.net/thredds/dodsC/data/emodnet-projects/v2025/By_sea_regions-water_body/Northeast_Atlantic_Ocean/Water_body_chlorophyll-a.4Danl.nc";
    String standard_name_vocabulary "CF Standard Name Table v70";
    String summary 
"Northeast Atlantic Ocean - DIVAnd 4D seasonal 6-year average analysis of Water body chlorophyll-a 1971/2024 v2025. Moving 6-year analysis of Water body chlorophyll-a in the NorthEast Atlantic for each season:
 - winter: January-March,
 - spring: April-June,
 - summer: July-September,
 - autumn: October-December. 
Every year of the time dimension corresponds to the 6-year centred average of each season. 6-year periods span from 1971/1976 until 2019/2024. Observation data span from 1971 to 2024. 
High-frequency observation trails were filtered to a 3h temporal resolution. 
Depth levels (International Oceanographic Data Exchange (IODE) standard depths): [0.0, 5.0, 10.0, 20.0, 30.0, 40.0, 50.0, 75.0, 100.0, 125.0, 150.0, 200.0, 250.0, 300.0]. 
Data sources: observational data from SeaDataNet/EMODNet Chemistry Data Network. 
Description of DIVAnd analysis: the computation was done with DIVAnd (Data-Interpolating Variational Analysis in n dimensions), version 2.7.12, using GEBCO 30 sec topography for the spatial connectivity of water masses. The horizontal resolution of the produced DIVAnd maps is 0.1 degrees. Horizontal correlation length varies from 200km in open sea regions to 50km at the coast. Vertical correlation length is defined as twice the vertical resolution. Signal-to-noise ratio was fixed to 1 for vertical profiles and 0.1 for time series to account for the redundancy in the time series observations. A logarithmic transformation (DIVAnd.loglin) was applied to the data prior to the analysis. Background field: a vertically-filtered profile of the seasonal data mean value (including all years) is substracted from the data. 
Detrending of data: no, advection constraint applied: no. 
Units: mg/m3.";
    String title "Northeast Atlantic Ocean, DIVAnd 4D seasonal 6-year average analysis of Water body chlorophyll-a 1971/2024 v2025 [observations]";
  }
}

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The URL specifies what you want: the dataset, a description of the graph or the subset of the data, and the file type for the response.

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For example,
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