Make A Graph

Dataset Title:	Daily mean fields for product GLOBAL_REANALYSIS_PHY_001_031 Salinity_Model_2001
Institution:	Mercator Ocean (Dataset ID: salinity_model_g_2001)
Information:	Summary \| License \| FGDC \| ISO 19115 \| Metadata \| Background \| Data Access Form \| Files

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Graph Type:
X Axis:
Y Axis:
Color:

Dimensions

Start

Stop

time (UTC)

specify just 1 value →

latitude (degrees_north)

longitude (degrees_east)

Graph Settings
Color Bar:	Continuity:	Scale:
Minimum:	Maximum:	N Sections:
Draw land mask:
Y Axis Minimum:	Maximum:

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

Optional:
Then set the File Type: (File Type information)
and

or view the URL:
(Documentation / Bypass this form

)

Click on the map to specify a new center point.

Zoom:

[The graph you specified. Please be patient.]

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 9.783072e+8, 1.0097568e+9;
    String axis "T";
    String calendar "gregorian";
    String ioos_category "Time";
    String long_name "Time";
    String standard_name "time";
    String time_origin "01-JAN-1970 00:00:00";
    String units "seconds since 1970-01-01T00:00:00Z";
  }
  latitude {
    String _CoordinateAxisType "Lat";
    Float32 actual_range -80.0, 90.0;
    String axis "Y";
    String ioos_category "Location";
    String long_name "Latitude";
    String standard_name "latitude";
    Float64 step 0.25;
    String unit_long "Degrees North";
    String units "degrees_north";
    Float32 valid_max 90.0;
    Float32 valid_min -80.0;
  }
  longitude {
    String _CoordinateAxisType "Lon";
    Float32 actual_range -180.0, 179.75;
    String axis "X";
    String ioos_category "Location";
    String long_name "Longitude";
    String standard_name "longitude";
    Float64 step 0.25;
    String unit_long "Degrees East";
    String units "degrees_east";
    Float32 valid_max 179.75;
    Float32 valid_min -180.0;
  }
  so_glor {
    Float32 _FillValue 9.96921e+36;
    String cell_methods "area: mean";
    Float64 colorBarMaximum 38.0;
    Float64 colorBarMinimum 32.0;
    String ioos_category "Salinity";
    Float64 least_significant_digit 6;
    String long_name "Salinity";
    String standard_name "sea_water_practical_salinity";
    String unit_long "Practical Salinity Unit";
    String units "PSU";
    Float32 valid_max 41.4194;
    Float32 valid_min 0.00700601;
  }
  NC_GLOBAL {
    String area "Global";
    String cdm_data_type "Grid";
    String comment "Salinity data have been calculated at a depth of 0.50576 m";
    String contact "servicedesk.cmems@mercator-ocean.eu";
    String Conventions "CF-1.10, COARDS, ACDD-1.3";
    String creator_email "servicedesk.cmems@mercator-ocean.eu";
    String creator_name "Mercator Ocean";
    String creator_type "person";
    String creator_url "http://marine.copernicus.eu";
    String credit "E.U. Copernicus Marine Service Information (CMEMS)";
    String dataset "global-reanalysis-phy-001-031-grepv2-daily";
    Float64 Easternmost_Easting 179.75;
    Float64 geospatial_lat_max 90.0;
    Float64 geospatial_lat_min -80.0;
    Float64 geospatial_lat_resolution 0.25;
    String geospatial_lat_units "degrees_north";
    Float64 geospatial_lon_max 179.75;
    Float64 geospatial_lon_min -180.0;
    Float64 geospatial_lon_resolution 0.25;
    String geospatial_lon_units "degrees_east";
    String history 
"Copernicus Marine Service
2025-04-30T03:59:17Z (local files)
2025-04-30T03:59:17Z https://erddap.aoml.noaa.gov/hdb/griddap/salinity_model_g_2001.das";
    String histoty "Creation 2019-Feb-06 13:46:36 GMT+0200";
    String infoUrl "http://marine.copernicus.eu";
    String institution "Mercator Ocean";
    String keywords "daily, data, day, density, earth, Earth Science > Oceans > Salinity/Density > Salinity, fields, global, latitude, longitude, mean, mercator, ocean, oceans, phy, practical, product, reanalysis, salinity, science, sea, sea_water_practical_salinity, seawater, so_glor, time, water";
    String keywords_vocabulary "GCMD Science Keywords";
    String licence "http://marine.copernicus.eu/services-portfolio/service-commitments-and-licence/";
    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.";
    Float64 Northernmost_Northing 90.0;
    String producer "CMEMS - Global Monitoring and Forecasting Centre";
    String product "GLOBAL_REANALYSIS_PHY_001_031";
    String product_user_manual "http://marine.copernicus.eu/documents/PUM/CMEMS-GLO-PUM-001-031.pdf";
    String quality_information_document "http://marine.copernicus.eu/documents/QUID/CMEMS-GLO-QUID-001_031.pdf";
    String references "http://marine.copernicus.eu";
    String source "Copernicus Marine Service";
    String sourceUrl "(local files)";
    Float64 Southernmost_Northing -80.0;
    String standard_name_vocabulary "CF Standard Name Table v70";
    String summary "Salinity data have been calculated at a depth of 0.50576 m";
    String time_coverage_end "2001-12-31T00:00:00Z";
    String time_coverage_start "2001-01-01T00:00:00Z";
    String title "Daily mean fields for product GLOBAL_REANALYSIS_PHY_001_031 Salinity_Model_2001";
    Float64 Westernmost_Easting -180.0;
  }
}

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.