Data Access Form

Dataset Title:	MHW Raw / WMO_Climatology / 95p / duration / 5_days / categories
Institution:	Danish Meteorological Institute (Dataset ID: mhw_raw_wmoClim_95p_5d_cat)
Information:	Summary \| License \| FGDC \| ISO 19115 \| Metadata \| Background \| Files \| Make a graph

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Dimensions	Size	Spacing
time (UTC)	83	5 days 10h 40m 59s (uneven)

latitude (degrees_north)	3600	0.05 (uneven)

longitude (degrees_east)	7200	0.05 (uneven)

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

cat_HW (Marine heatwave category (Hobday et al. 2016), 1)

cat_CS (Marine cold-spell category (Hobday et al. 2016), 1)

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 {
  time {
    UInt32 _ChunkSizes 512;
    String _CoordinateAxisType "Time";
    Float64 actual_range 3.471552e+8, 3.857328e+8;
    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";
    Float64 actual_range -89.9749984741211, 89.9749984741211;
    String axis "Y";
    String ioos_category "Location";
    String long_name "Latitude";
    String standard_name "latitude";
    String units "degrees_north";
  }
  longitude {
    String _CoordinateAxisType "Lon";
    Float64 actual_range -179.97500610351562, 179.97500610351562;
    String axis "X";
    String ioos_category "Location";
    String long_name "Longitude";
    String standard_name "longitude";
    String units "degrees_east";
  }
  cat_HW {
    UInt32 _ChunkSizes 1, 1, 7200;
    Float64 _FillValue NaN;
    Float64 colorBarMaximum 4.0;
    Float64 colorBarMinimum 0.0;
    String description "Integer marine heatwave category (1-4) based on the multiple of the heatwave threshold (p95 - mean) exceeded by the anomaly, following Hobday et al. (2016). A value of 0 indicates no active heatwave. Events require a minimum duration of 5 day(s) with gaps of <=2 day(s) bridged.";
    String flag_meanings "none moderate strong severe extreme";
    Int32 flag_values 0, 1, 2, 3, 4;
    String ioos_category "Other";
    String long_name "Marine heatwave category (Hobday et al. 2016)";
    Float64 missing_value NaN;
    String units "1";
  }
  cat_CS {
    UInt32 _ChunkSizes 1, 1, 7200;
    Float64 _FillValue NaN;
    Float64 colorBarMaximum 4.0;
    Float64 colorBarMinimum 0.0;
    String description "Integer marine cold-spell category (1-4), given as a positive magnitude, based on the multiple of the cold-spell threshold (p5 - mean) exceeded by the (negative) anomaly, following Hobday et al. (2016). A value of 0 indicates no active cold spell. Events require a minimum duration of 5 day(s) with gaps of <=2 day(s) bridged.";
    String flag_meanings "none moderate strong severe extreme";
    Int32 flag_values 0, 1, 2, 3, 4;
    String ioos_category "Other";
    String long_name "Marine cold-spell category (Hobday et al. 2016)";
    Float64 missing_value NaN;
    String units "1";
  }
  NC_GLOBAL {
    String _NCProperties "version=2,netcdf=4.8.1,hdf5=1.12.2";
    String CDI "Climate Data Interface version 2.1.1 (https://mpimet.mpg.de/cdi)";
    String cdm_data_type "Grid";
    String CDO "Climate Data Operators version 2.1.1 (https://mpimet.mpg.de/cdo)";
    String Climatology "1991-2020";
    String Conventions "CF-1.8, COARDS, ACDD-1.3";
    String creator_email "algh@dmi.dk";
    String creator_name "Alex Hayward";
    Int32 Duration 5;
    Float64 Easternmost_Easting 179.97500610351562;
    String Experiment "WMO Baseline 95-th percentile";
    Float64 geospatial_lat_max 89.9749984741211;
    Float64 geospatial_lat_min -89.9749984741211;
    String geospatial_lat_units "degrees_north";
    Float64 geospatial_lon_max 179.97500610351562;
    Float64 geospatial_lon_min -179.97500610351562;
    String geospatial_lon_units "degrees_east";
    String history 
"2026-06-04T21:55:47Z (local files)
2026-06-04T21:55:47Z http://erddap.alex-hayward.com/erddap/griddap/mhw_raw_wmoClim_95p_5d_cat.das";
    String infoUrl "https://doi.org/10.3030/101136548";
    String institution "Danish Meteorological Institute";
    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 89.9749984741211;
    Int32 Percentile_Thresholds 5, 95;
    String project_code "ObsSea4Clim";
    String project_DOI "https://doi.org/10.3030/101136548";
    String project_edmerp "13765";
    String project_edmerp_uri "https://edmerp.seadatanet.org/report/13765";
    String project_id "101136548";
    String project_name "Ocean observations and indicators for climate and assessments";
    String project_statement "Funded by the European Union. Views and opinions expressed are however those of the author(s) only and do not necessarily reflect those of the European Union or the European Research Executive Agency (REA). Neither the European Union nor the granting authority can be held responsible for them.";
    String projectName "wmo_95_5";
    String sourceUrl "(local files)";
    Float64 Southernmost_Northing -89.9749984741211;
    String summary "Marine-heatwave product (Hobday et al. framework) from ESA SST-CCI. Experiment: WMO Baseline 95-th percentile. Climatology baseline: 1991-2020. Path: Raw/WMO_Climatology/95p/duration/5_days/categories. ObsSea4Clim project (EU grant 101136548).";
    String time_coverage_end "1982-03-23T12:00:00Z";
    String time_coverage_start "1981-01-01T00:00:00Z";
    String title "MHW Raw / WMO_Climatology / 95p / duration / 5_days / categories";
    Float64 Westernmost_Easting -179.97500610351562;
    Int32 xRange -180, 180;
    Int32 yRange -90, 90;
  }
}

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.