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Dataset Title:	North Sea, DIVAnd 4D 6-year seasonal analysis of Water body chlorophyll-a 1980/ 2023 v2025 [observations]
Institution:	Aarhus University, Department of Bioscience, Marine Ecology Roskilde (Dataset ID: oceanbrowser_opendap_df71_ef8c_fe38)
Information:	Summary \| License \| Metadata \| Background \| Data Access Form

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Things You Can Do With Your Graphs

Well, you can do anything you want with your graphs, of course. But some things you might not have considered are:

Web page authors can embed a graph of the latest data in a web page using HTML <img> tags.
Anyone can use ERDDAPs Slide Sorter to build a personal web page that displays graphs with the latest data (or other images or HTML content), each in its own, draggable slide.

The Dataset Attribute Structure (.das) for this Dataset

Attributes {
  observations {
    Int32 actual_range 0, 3678858;
    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 and visualization of Water body chlorophyll-a in the North Sea. Four seasons (December-February, March-May, June-August, September-November). Data Sources: observational data from SeaDataNet/EMODnet Chemistry Data Network. Description of DIVA analysis: Geostatistical data analysis by DIVAnd (Data-Interpolating Variational Analysis) tool, version 2.7.12. results were subjected to the minfield option in DIVAnd to avoid negative/underestimated values in the interpolated results; error threshold masks L1 (0.3) and L2 (0.5) are included as well as the unmasked field. The depth dimension allows visualizing the gridded field at various depths.";
    String acknowledgement "EMODNET-chemistry";
    String area_keywords "North Sea";
    String area_keywords_urn "SDN:C19::1_2";
    String Author_e_mail "Martin MÃƒÂ¸rk Larsen <mml@bios.au.dk>, Jonas K. RÃƒÂ¸mer <jkr@bios.au.dk>";
    String bathymetry_source "GEBCO Compilation Group (2020) GEBCO 2020 Grid (doi:10.5285/a29c5465-b138-234d-e053-6c86abc040b9), GEBCO Compilation Group (2025) GEBCO 2025 Grid (doi:10.5285/37c52e96-24ea-67ce-e063-7086abc05f29)";
    String cdm_data_type "Grid";
    String comment "Every year of the time dimension corresponds to a 6-year centred average for the seasons: winter (Dec-Feb), spring (Mar-May), summer (Jun-Aug), autumn (Sep-Nov). Horizontal resolution 0.1Â°";
    String Conventions "CF-1.8, COARDS, ACDD-1.3";
    String creator_name "Aarhus University, Department of Bioscience, Marine Ecology Roskilde";
    String creator_type "institution";
    String creator_url "https://doi.org/doi_of_doc";
    String data_access "http://ec.oceanbrowser.net/data/emodnet-domains";
    String date "2025-10-28T12:00:00";
    String documentation "https://doi.org/doi_of_doc";
    String doi "https://doi.org/10.13120/eec9f7ff-9969-447c-a6a2-4b06f5741d2c";
    String file_name "./NorthSea/output/Water_body_chlorophyll-a_NorthSea.4Danl.nc";
    String history 
"Tue Nov  4 11:29:52 2025: ncks -7 -O -L 5 --baa=4 --ppc default=3 /home/ctroupin/data/EMODnet-Chemistry/Eutrophication2024/Results/By_sea_regions-water_body/North_Sea//Water_body_chlorophyll-a.4Danl.nc /home/ctroupin/data/EMODnet-Chemistry/Eutrophication2024/Results/By_sea_regions-water_body/North_Sea//Water_body_chlorophyll-a.4Danl.nc
Wed Oct 29 11:57:12 2025: ncatted -O -a date,global,o,c,2025-10-28T12:00:00 -a product_version,global,o,c,3.0 -a bathymetry_source,global,o,c,GEBCO Compilation Group (2020) GEBCO 2020 Grid (doi:10.5285/a29c5465-b138-234d-e053-6c86abc040b9), GEBCO Compilation Group (2025) GEBCO 2025 Grid (doi:10.5285/37c52e96-24ea-67ce-e063-7086abc05f29) -a abstract,global,o,c,Moving 6-year analysis and visualization of Water body chlorophyll-a in the North Sea. Four seasons (December-February, March-May, June-August, September-November). Data Sources: observational data from SeaDataNet/EMODnet Chemistry Data Network. Description of DIVA analysis: Geostatistical data analysis by DIVAnd (Data-Interpolating Variational Analysis) tool, version 2.7.12. results were subjected to the minfield option in DIVAnd to avoid negative/underestimated values in the interpolated results; error threshold masks L1 (0.3) and L2 (0.5) are included as well as the unmasked field. The depth dimension allows visualizing the gridded field at various depths. -a product_code,global,o,c,AU-ECOS-NORTH-SEA-CHLA-3.0.ANA -a title,global,o,c,North Sea - DIVAnd 4D 6-year seasonal analysis of Water body chlorophyll-a 1980/2023 v2025 -a doi,global,o,c,https://doi.org/10.13120/eec9f7ff-9969-447c-a6a2-4b06f5741d2c -a product_id,global,o,c,eec9f7ff-9969-447c-a6a2-4b06f5741d2c Water_body_chlorophyll-a.4Danl.nc fordivadoxml/Water_body_chlorophyll-a.4Danl.nc
Thu Oct 23 11:14:58 2025: ncks -O -x -v obslon,obslat,obsdepth,obstime,obsid Water_body_chlorophyll-a.4Danl.nc Water_body_chlorophyll-a.4Danl.nc
Mon Oct 20 14:38:30 2025: ncrcat old/Water_body_chlorophyll-a.4Danl.nc new/Water_body_chlorophyll-a.4Danl.nc merged/Water_body_chlorophyll-a.4Danl.nc
Mon Oct 20 14:23:55 2025: ncks -O --mk_rec_dmn time old/Water_body_chlorophyll-a.4Danl.nc old/Water_body_chlorophyll-a.4Danl.nc
2026-03-13T23:58:04Z http://opendap.oceanbrowser.net/thredds/dodsC/data/emodnet-projects/v2025/By_sea_regions-water_body/North_Sea/Water_body_chlorophyll-a.4Danl.nc
2026-03-13T23:58:04Z https://erddap.emodnet.eu/griddap/oceanbrowser_opendap_df71_ef8c_fe38.das";
    String id "DatasetScan/emodnet-projects/v2025/By_sea_regions-water_body/North_Sea/Water_body_chlorophyll-a.4Danl.nc";
    String infoUrl "https://doi.org/doi_of_doc";
    String institution "Aarhus University, Department of Bioscience, Marine Ecology Roskilde";
    String institution_urn "SDN:EDMO::729";
    String keywords "6-year, aarhus, analysis, bioscience, body, chla, chlorophyll, chlorophyll-a, data, department, depth, divand, ecology, latitude, longitude, marine, north, obsdepth, observations, obslat, obslon, obstime, roskilde, sea, seasonal, seawater, time, university, 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 "AU-ECOS-NORTH-SEA-CHLA-3.0.ANA";
    String product_id "eec9f7ff-9969-447c-a6a2-4b06f5741d2c";
    String product_version "3.0";
    String project "EMODNET Chemistry phase 5";
    String search_keywords "Chlorophyll pigment concentrations in water bodies";
    String search_keywords_urn "SDN:P02::CPWC";
    String source "observational data from SeaDataNet and World Ocean Atlas";
    String sourceUrl "http://opendap.oceanbrowser.net/thredds/dodsC/data/emodnet-projects/v2025/By_sea_regions-water_body/North_Sea/Water_body_chlorophyll-a.4Danl.nc";
    String standard_name_vocabulary "CF Standard Name Table v70";
    String summary "North Sea - DIVAnd 4D 6-year seasonal analysis of Water body chlorophyll-a 1980/2023 v2025. Moving 6-year analysis and visualization of Water body chlorophyll-a in the North Sea. Four seasons (December-February, March-May, June-August, September-November). Data Sources: observational data from SeaDataNet/EMODnet Chemistry Data Network. Description of DIVA analysis: Geostatistical data analysis by DIVAnd (Data-Interpolating Variational Analysis) tool, version 2.7.12. results were subjected to the minfield option in DIVAnd to avoid negative/underestimated values in the interpolated results; error threshold masks L1 (0.3) and L2 (0.5) are included as well as the unmasked field. The depth dimension allows visualizing the gridded field at various depths.";
    String title "North Sea, DIVAnd 4D 6-year seasonal analysis of Water body chlorophyll-a 1980/2023 v2025 [observations]";
    String WEB_visualisation "http://ec.oceanbrowser.net/emodnet/";
  }
}

Using griddap to Request Data and Graphs from Gridded Datasets

griddap lets you request a data subset, graph, or map from a gridded dataset (for example, sea surface temperature data from a satellite), via a specially formed URL. griddap uses the OPeNDAP (external link)

Data Access Protocol (DAP) (external link)

and its projection constraints (external link)

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.

(easy) You can get data by using the dataset's Data Access Form. It makes the URL for you.
(easy) You can make a graph or map by using the dataset's Make A Graph form. It makes the URL for you.
(not hard) You can bypass the forms and get the data or make a graph or map by generating the URL by hand or with a computer program or script.

griddap request URLs must be in the form
https://coastwatch.pfeg.noaa.gov/erddap/griddap/datasetID.fileType{?query}
For example,
https://coastwatch.pfeg.noaa.gov/erddap/griddap/jplMURSST41.htmlTable?analysed_sst[(2002-06-01T09:00:00Z)][(-89.99):1000:(89.99)][(-179.99):1000:(180.0)]
Thus, the query is often a data variable name (e.g., analysed_sst), followed by [(start):stride:(stop)] (or a shorter variation of that) for each of the variable's dimensions (for example, [time][latitude][longitude]).

For details, see the griddap Documentation.

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