Data Access Form

Dataset Title:	Global Drifter Program - Climatology - Current Variance
Institution:	NOAA/AOML & Univ. Miami (Dataset ID: drifter_currentvariance)
Information:	Summary \| License \| FGDC \| ISO 19115 \| Metadata \| Background \| Files \| Make a graph

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Dimensions	Size	Spacing
longitude (degrees_east)	1440	0.25 (even)

latitude (degrees_north)	632	0.25 (even)

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

Up2bar (Zonal Velocity Variance, mean(u-prime-squared), (meters per second)^2)

Vp2bar (Meridional Velocity Variance, mean(v-prime-squared), (meters per second)^2)

rA (Variance Ellipse semimajor axis, (meters per second)^2)

rB (Variance Ellipse semiminor axis, (meters per second)^2)

angle (degrees: 0=east/west, 45=northeast/southwest, 90=north/south)

N (Number of drifter-days per square degree, drifter-days per square degree)

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 {
  longitude {
    UInt32 _ChunkSizes 1440;
    String _CoordinateAxisType "Lon";
    Float64 actual_range -179.875, 179.875;
    String axis "X";
    String coordinates "Lat";
    String ioos_category "Location";
    String long_name "Longitude";
    String standard_name "longitude";
    String units "degrees_east";
    Float64 valid_max 179.875;
    Float64 valid_min -179.875;
  }
  latitude {
    UInt32 _ChunkSizes 632;
    String _CoordinateAxisType "Lat";
    Float64 actual_range -72.875, 84.875;
    String axis "Y";
    String coordinates "Lat";
    String ioos_category "Location";
    String long_name "Latitude";
    String standard_name "latitude";
    String units "degrees_north";
    Float64 valid_max 84.875;
    Float64 valid_min -72.875;
  }
  Up2bar {
    Float64 colorBarMaximum 0.5;
    Float64 colorBarMinimum 0.0;
    String long_name "Zonal Velocity Variance, mean(u-prime-squared)";
    String units "(meters per second)^2";
    Float64 valid_max 0.47488;
    Float64 valid_min 3.5059e-4;
  }
  Vp2bar {
    Float64 colorBarMaximum 0.4;
    Float64 colorBarMinimum 0.0;
    String long_name "Meridional Velocity Variance, mean(v-prime-squared)";
    String units "(meters per second)^2";
    Float64 valid_max 0.38285;
    Float64 valid_min 3.563e-4;
  }
  rA {
    Float64 colorBarMaximum 0.5;
    Float64 colorBarMinimum 0.0;
    String long_name "Variance Ellipse semimajor axis";
    String units "(meters per second)^2";
    Float64 valid_max 0.4554;
    Float64 valid_min 5.1876e-4;
  }
  rB {
    Float64 colorBarMaximum 0.35;
    Float64 colorBarMinimum 0.0;
    String long_name "Variance Ellipse semiminor axis";
    String units "(meters per second)^2";
    Float64 valid_max 0.32858;
    Float64 valid_min 2.4296e-4;
  }
  angle {
    Float64 colorBarMaximum 90.0;
    Float64 colorBarMinimum -90.0;
    String long_name "Orientation Angle of Variance Ellipse";
    String units "degrees: 0=east/west, 45=northeast/southwest, 90=north/south";
    Float64 valid_max 89.9995;
    Float64 valid_min -89.9998;
  }
  N {
    Float64 colorBarMaximum 2000.0;
    Float64 colorBarMinimum 0.0;
    String long_name "Number of drifter-days per square degree";
    String units "drifter-days per square degree";
    Float64 valid_max 1712.8255;
    Float64 valid_min 13.0507;
  }
  NC_GLOBAL {
    String author "Laurindo, Mariano, and Lumpkin (2017), Deep-Sea Res. I, doi:10.1016/j.dsr.2017.04.009";
    String cdm_data_type "Grid";
    String Conventions "COARDS, CF-1.10, ACDD-1.3";
    String creator_email "aoml.webmaster@noaa.gov";
    String creator_name "NOAA/AOML & Univ. Miami";
    String creator_type "institution";
    String creator_url "https://www.aoml.noaa.gov/";
    String datadate "Climatology uses data through 28-Feb-2023";
    String date2 "File created 21-Aug-2023 09:38:21";
    String description "Surface Current Variance from Drifter Data";
    Float64 Easternmost_Easting 179.875;
    Float64 geospatial_lat_max 84.875;
    Float64 geospatial_lat_min -72.875;
    Float64 geospatial_lat_resolution 0.25;
    String geospatial_lat_units "degrees_north";
    Float64 geospatial_lon_max 179.875;
    Float64 geospatial_lon_min -179.875;
    Float64 geospatial_lon_resolution 0.25;
    String geospatial_lon_units "degrees_east";
    String history 
"2025-10-28T14:51:21Z (local files)
2025-10-28T14:51:21Z https://erddap.aoml.noaa.gov/gdp/erddap/griddap/drifter_currentvariance.das";
    String infoUrl "https://www.aoml.noaa.gov/";
    String institution "NOAA/AOML & Univ. Miami";
    String keywords "angle, aoml, atlantic, axis, data, days, degree, drifter, drifter-days, ellipse, laboratory, latitude, longitude, mean, meridional, meteorological, miami, noaa, number, oceanographic, orientation, per, prime, semimajor, semiminor, square, squared, u-prime-squared, university, Up2bar, v-prime-squared, variance, velocity, Vp2bar, zonal";
    String license "Creative Commons Attribution 4.0 (https://creativecommons.org/licenses/by/4.0/) This study used data collected and made freely available by the NOAA Global Drifter Program (https://www.aoml.noaa.gov/phod/gdp/) accessed from https://erddap.aoml.noaa.gov/gdp/erddap/index.html";
    Float64 Northernmost_Northing 84.875;
    String sourceUrl "(local files)";
    Float64 Southernmost_Northing -72.875;
    String standard_name_vocabulary "CF Standard Name Table v70";
    String summary "Current variance (eddy kinetic energy) derived from residuals with respect to the time-mean, seasonal, spatial gradient, and SOI-related currents";
    String title "Global Drifter Program - Climatology - Current Variance";
    String version "3.10";
    Float64 Westernmost_Easting -179.875;
  }
}

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.