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Dataset Title:	Chlorophyll-a Satellite Data for the Estuary and the Gulf of St. Lawrence: VIIRS \| Données satellitaires de chlorophylle-a pour l'estuaire et le golfe du Saint-Laurent : VIIRS
Institution:	Fisheries and Oceans Canada (Dataset ID: mpoChloroSatellitesViirs)
Information:	Summary \| License \| FGDC \| ISO 19115 \| Metadata \| Background \| Data Access Form \| Files

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Y Axis:
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time (UTC)

specify just 1 value →

latitude (degrees_north)

longitude (degrees_east)

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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 {
  time {
    String _CoordinateAxisType "Time";
    Float64 actual_range 1.3255488e+9, 1.5961536e+9;
    String axis "T";
    String coverage_content_type "coordinate";
    String ioos_category "Time";
    String long_name "Date";
    String nerc_identifier "https://vocab.nerc.ac.uk/collection/P07/current/CFSN0115/";
    String standard_name "time";
    String time_origin "01-JAN-1970 00:00:00";
    String time_precision "1970-01-01";
    String units "seconds since 1970-01-01T00:00:00Z";
  }
  latitude {
    String _CoordinateAxisType "Lat";
    Float32 actual_range 45.20833, 51.875;
    String axis "Y";
    String description "Latitude coordinates of the measurement sites in decimal degrees (degrees north)";
    String ioos_category "Location";
    String long_name "Latitude";
    String nerc_identifier "https://vocab.nerc.ac.uk/collection/P07/current/CFSN0600/";
    Float64 original_name NaN;
    String standard_name "latitude";
    String units "degrees_north";
  }
  longitude {
    String _CoordinateAxisType "Lon";
    Float32 actual_range -70.79166, -55.45833;
    String axis "X";
    String description "Longitude coordinates of the measurement sites in decimal degrees (degrees east)";
    String ioos_category "Location";
    String long_name "Longitude";
    String nerc_identifier "https://vocab.nerc.ac.uk/collection/P07/current/CFSN0554/";
    Float64 original_name NaN;
    String standard_name "longitude";
    String units "degrees_east";
  }
  chl_a_Multisat {
    Float64 colorBarMaximum 66.0;
    Float64 colorBarMinimum 0.07;
    String colorBarScale "Log";
    String description "Chlorophyll a concentration determined by analysis and synthesis of calibrated data from multiple sensors on one or more satellite platforms.";
    String ioos_category "Ocean Color";
    String long_name "Chlorophyll a Concentration";
    String method "Empirical Orthogonal Functions (EOF)";
    String nerc_BODC_identifier "https://vocab.nerc.ac.uk/collection/P01/current/CHLAMSAT/";
    String nerc_identifier "https://vocab.nerc.ac.uk/collection/P07/current/CF14N7/";
    String nerc_standard_name "chl_a_Multisat";
    String original_name "chl_eof";
    String standard_name "concentration_of_chlorophyll_in_sea_water";
    String units "mg m-3";
  }
  Rrs_410nm_model {
    Float64 colorBarMaximum 0.033;
    Float64 colorBarMinimum 1.0e-4;
    String colorBarScale "Log";
    String description "Remote sensing reflectance of electromagnetic radiation (410nm wavelength) {Rrs} from the water body by model prediction";
    String ioos_category "Optical Properties, Ocean Color";
    String long_name "Electromagnetic Radiation (410nm wavelength)";
    String nerc_identifier "https://vocab.nerc.ac.uk/collection/P01/current/RRSWMP01/";
    String nerc_standard_name "Rrs_410nm_model";
    String original_name "Rrs_410";
    String units "sr-1";
  }
  Rrs_443nm_model {
    Float64 colorBarMaximum 0.039;
    Float64 colorBarMinimum 1.0e-4;
    String colorBarScale "Log";
    String description "Remote sensing reflectance of electromagnetic radiation (443nm wavelength) {Rrs} from the water body by model prediction";
    String ioos_category "Optical Properties, Ocean Color";
    String long_name "Electromagnetic Radiation (443nm wavelength)";
    String nerc_identifier "https://vocab.nerc.ac.uk/collection/P01/current/RRSWMP03/";
    String nerc_standard_name "Rrs_443nm_model";
    String original_name "Rrs_443";
    String units "sr-1";
  }
  Rrs_486nm_model {
    Float64 colorBarMaximum 0.044;
    Float64 colorBarMinimum 1.0e-4;
    String colorBarScale "Log";
    String description "Remote sensing reflectance of electromagnetic radiation (486nm wavelength) {Rrs} from the water body by model prediction";
    String ioos_category "Optical Properties, Ocean Color";
    String long_name "Electromagnetic Radiation (486nm wavelength)";
    String nerc_identifier "https://vocab.nerc.ac.uk/collection/P01/current/RRSWMP05/";
    String nerc_standard_name "Rrs_486nm_model";
    String original_name "Rrs_486";
    String units "sr-1";
  }
  Rrs_551nm_model {
    Float64 colorBarMaximum 0.027;
    Float64 colorBarMinimum 1.0e-4;
    String colorBarScale "Log";
    String description "Remote sensing reflectance of electromagnetic radiation (551nm wavelength) {Rrs} from the water body by model prediction";
    String ioos_category "Optical Properties, Ocean Color";
    String long_name "Electromagnetic Radiation (551nm wavelength)";
    String nerc_identifier "https://vocab.nerc.ac.uk/collection/P01/current/RRSWMP11/";
    String nerc_standard_name "Rrs_551nm_model";
    String original_name "Rrs_551";
    String units "sr-1";
  }
  Rrs_671nm_model {
    Float64 colorBarMaximum 0.028;
    Float64 colorBarMinimum 1.0e-4;
    String colorBarScale "Log";
    String description "Remote sensing reflectance of electromagnetic radiation (671nm wavelength) {Rrs} from the water body by model prediction";
    String ioos_category "Optical Properties, Ocean Color";
    String long_name "Electromagnetic Radiation (671nm wavelength)";
    String nerc_identifier "https://vocab.nerc.ac.uk/collection/P01/current/RRSWMP20/";
    String nerc_standard_name "Rrs_671nm_model";
    String original_name "Rrs_671";
    String units "sr-1";
  }
  NC_GLOBAL {
    String cdm_data_type "Grid";
    String Conventions "CF-1.11, COARDS ACDD-1.3";
    String creator_email "Julien.Laliberte@dfo-mpo.gc.ca";
    String creator_identifier "https://orcid.org/0000-0001-6698-029X";
    String creator_name "Julien Laliberté";
    String data_curator "Observatoire global du Saint-Laurent";
    String dataset_status "OnGoing";
    String date_created "2020-08-04";
    String DOI "https://doi.org/10.26071/ogsl-5mak-9r77";
    Float64 Easternmost_Easting -55.45833;
    String format_version "v2";
    Float64 geospatial_lat_max 51.875;
    Float64 geospatial_lat_min 45.20833;
    Float64 geospatial_lat_resolution 0.08438822784810131;
    String geospatial_lat_units "degrees_north";
    Float64 geospatial_lon_max -55.45833;
    Float64 geospatial_lon_min -70.79166;
    Float64 geospatial_lon_resolution 0.08378868852459015;
    String geospatial_lon_units "degrees_east";
    String grid_resolution "9 km";
    String history 
"First version was text file publish directly in the SLGO catalogue. This second version is completely standardized and in NetCDF format.
2024-11-05T09:21:16Z (local files)
2024-11-05T09:21:16Z https://erddap.ogsl.ca/griddap/mpoChloroSatellitesViirs.das";
    String infoUrl "https://doi.org/10.26071/ogsl-5mak-9r77";
    String institution "Fisheries and Oceans Canada";
    String institution_identifier "https://ror.org/02qa1x782";
    String key_variables "oceanColor";
    String keywords "chlorophyll a, ocean colour, phytoplancton, remote sensing";
    String keywords_vocabulary "GCMD Science Keywords";
    String license "Open Government Licence - Canada";
    String licenseUrl "https://open.canada.ca/en/open-government-licence-canada";
    Float64 Northernmost_Northing 51.875;
    String platform "satellite";
    String platform_COSPARid "2017-073A";
    String platform_id "2016-011A, 2018-039A, 2002-022A, 2002-009A, 1997-037A, 2017-073A";
    String platform_name "NOAA 20";
    String platform_vocabulary "https://vocab.nerc.ac.uk/collection/L06/current/";
    String product_version "v2";
    String project "Coastal Environmental Baseline Program";
    String publisher "Observatoire global du Saint-Laurent";
    String publisher_identifier "https://ror.org/03wfagk22";
    String related_datasets 
"https://erddap.preprod.ogsl.ca/erddap/griddap/mpoChloroSatellitesAqua.html
        https://erddap.ogsl.ca/erddap/info/mpoChloroSatellitesCci/index.html
        https://erddap.ogsl.ca/erddap/info/mpoChloroSatellitesMeris/index.html
        https://erddap.ogsl.ca/erddap/griddap/mpoChloroSatellitesSeawifs.html
        https://erddap.ogsl.ca/erddap/griddap/mpoChloroSatellitesCciMonthly.html";
    String sensor "Visible and Infrared Imager/Radiometer Suite (VIIRS)";
    String sourceUrl "(local files)";
    Float64 Southernmost_Northing 45.20833;
    String standard_name_nerc_vocabulary "The NERC Vocabulary Server (NVS).";
    String standard_name_vocabulary "CF Standard Name Table v85";
    String summary 
"The colour of seawater, seen from space, is used to estimate the chlorophyll content in the water. This pigment is an index of the biomass of microscopic algae. Compared to the Atlantic Ocean, the waters of the Estuary and the Gulf of St. Lawrence are rather isolated and are strongly mixed with fresh water from many rivers.

The method for retrieving chlorophyll must be adapted to these specificities. This dataset presents the result of a method developed to find the concentration of chlorophyll-a derived by various satellites (5) in the estuary and the Gulf of St. Lawrence. The satellite Visible and Infrared Imager/Radiometer Suite (VIIRS) is still active and collect daily data.";
    String summary_fr 
"La couleur de l'eau des océans, vue de l'espace, est utilisée pour estimer la concentration de chlorophylle dans l'eau. Ce pigment est un indice de la biomasse algaire microscopique. En comparaison avec l'Océan Atlantique, les eaux de l'estuaire et du golfe du Saint-Laurent sont relativement isolées et fortement mélangées avec de l'eau douce provenant de nombreuses rivières.
        
        La méthode pour déterminer la concentration en chlorophylle doit être adaptée à ces spécificités. Cette base de données présente les résultats d'une méthode développée pour trouver la concentration en chlorophylle-a dérivées à partir de différents satellites (5) dans l'estuaire et le golfe du Saint-Laurent. Le satellite VIIRS (Visible and Infrared Imager/Radiometer Suite) est toujours actif et collecte des données journalières.";
    String time_coverage_end "2020-07-31";
    String time_coverage_start "2012-01-03";
    String title "Chlorophyll-a Satellite Data for the Estuary and the Gulf of St. Lawrence: VIIRS | Données satellitaires de chlorophylle-a pour l'estuaire et le golfe du Saint-Laurent : VIIRS";
    String update_frequency "Annually";
    Float64 Westernmost_Easting -70.79166;
  }
}

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.