Data Access Form

Dataset Title:	Estimated Seafloor Depth Gradients: ETOPO-22 (US Atlantic Coast)
Institution:	NOAA ERD (Dataset ID: erdEtopo22SeafloorGradient_Atlantic)
Information:	Summary \| License \| FGDC \| ISO 19115 \| Metadata \| Background \| Files \| Make a graph

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Dimensions	Size	Spacing
latitude (degrees_north)	7201	0.004166667 (even)

longitude (degrees_east)	6961	0.004166667 (even)

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

sea_floor_depth (m)

x_gradient (East-West Gradient of sea_floor depth, m)

y_gradient (North-South Gradient of sea_floor depth, m)

magnitude_gradient (Magnitude of sea_floor depth Gradient, m)

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 {
  latitude {
    String _CoordinateAxisType "Lat";
    Float32 actual_range 20.00208, 50.00208;
    String axis "Y";
    String ioos_category "Location";
    String long_name "Latitude";
    String reference_datum "geographical coordinates, WGS84 projection";
    String standard_name "latitude";
    String units "degrees_north";
    Float32 valid_max 50.002083;
    Float32 valid_min 20.002083;
  }
  longitude {
    String _CoordinateAxisType "Lon";
    Float32 actual_range -90.00208, -61.00208;
    String axis "X";
    String ioos_category "Location";
    String long_name "Longitude";
    String reference_datum "geographical coordinates, WGS84 projection";
    String standard_name "longitude";
    String units "degrees_east";
    Float32 valid_max -61.002083;
    Float32 valid_min -90.00208;
  }
  sea_floor_depth {
    Float32 _FillValue -99999.0;
    Float64 colorBarMaximum 8000.0;
    Float64 colorBarMinimum -8000.0;
    String colorBarPalette "TopographyDepth";
    String ioos_category "Location";
    String long_name "Sea Floor Depth";
    Float32 missing_value -9999.0;
    String standard_name "sea_floor_depth";
    String units "m";
  }
  x_gradient {
    Float32 _FillValue -9999.0;
    Float64 colorBarMaximum 8000.0;
    Float64 colorBarMinimum -8000.0;
    String colorBarPalette "TopographyDepth";
    String ioos_category "Location";
    String long_name "East-West Gradient of sea_floor depth";
    Float32 missing_value -99999.0;
    String standard_name "sea_floor_depth";
    String units "m";
  }
  y_gradient {
    Float32 _FillValue -9999.0;
    Float64 colorBarMaximum 8000.0;
    Float64 colorBarMinimum -8000.0;
    String colorBarPalette "TopographyDepth";
    String ioos_category "Location";
    String long_name "North-South Gradient of sea_floor depth";
    Float32 missing_value -9999.0;
    String standard_name "sea_floor_depth";
    String units "m";
  }
  magnitude_gradient {
    Float32 _FillValue -9999.0;
    Float64 colorBarMaximum 8000.0;
    Float64 colorBarMinimum -8000.0;
    String colorBarPalette "TopographyDepth";
    String ioos_category "Location";
    String long_name "Magnitude of sea_floor depth Gradient";
    Float32 missing_value -9999.0;
    String standard_name "sea_floor_depth";
    String units "m";
  }
  NC_GLOBAL {
    String cdm_data_type "Grid";
    String Conventions "COARDS, CF-1.10, ACDD-1.3";
    String creator_email "erd.data@noaa.gov";
    String creator_name "NOAA NMFS SWFSC ERD";
    String creator_type "institution";
    String creator_url "https://www.pfeg.noaa.gov";
    String defaultGraphQuery "&.draw=surface&.vars=longitude|latitude|magnitude_gradient&.colorBar=KT_amp|||0|700|&.bgColor=0xffccccff";
    Float64 Easternmost_Easting -61.00208;
    Float64 geospatial_lat_max 50.00208;
    Float64 geospatial_lat_min 20.00208;
    Float64 geospatial_lat_resolution 0.004166666666666667;
    String geospatial_lat_units "degrees_north";
    Float64 geospatial_lon_max -61.00208;
    Float64 geospatial_lon_min -90.00208;
    Float64 geospatial_lon_resolution 0.0041666666666666675;
    String geospatial_lon_units "degrees_east";
    Float64 grid_mapping_earth_radius 6367470.0;
    String grid_mapping_name "latitude_longitude";
    String history 
"created from etopo_22using python scikit-image canny algorithm, sigma = 12.5
2024-12-22T02:04:04Z (local files)
2024-12-22T02:04:04Z https://coastwatch.pfeg.noaa.gov/erddap/griddap/erdEtopo22SeafloorGradient_Atlantic.das";
    String infoUrl "https://www.pfeg.noaa.gov";
    String institution "NOAA ERD";
    String keywords "22sea, bathymetry, data, depth, earth, Earth Science > Oceans > Bathymetry/Seafloor Topography > Bathymetry, east, east-west, erd, estimatedetopo, floor, gradient, latitude, longitude, magnitude, magnitude_gradient, noaa, north, north-south, ocean, oceans, science, sea, sea_floor_depth, seafloor, south, topography, west, x_gradient, y_gradient";
    String keywords_vocabulary "GCMD Science Keywords";
    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 50.00208;
    String sourceUrl "(local files)";
    Float64 Southernmost_Northing 20.00208;
    String standard_name_vocabulary "CF Standard Name Table v55";
    String summary 
"Estimated sea_floor depth  x-gradient, y-gradient and gradient magnitude
using the Python scikit-image canny algorithm  with sigma = 12.5,x-gradient, y-gradient and gradient magnitude.";
    String title "Estimated Seafloor Depth Gradients: ETOPO-22 (US Atlantic Coast)";
    Float64 Westernmost_Easting -90.00208;
  }
}

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.