Make A Graph

Dataset Title:	SURF \| TPXO8 \| U Transport Q1 1/30 Degree
Institution:	Oregon State University (Dataset ID: surf_osu_tpxo8_u_q1_30_v1)
Information:	Summary \| License \| FGDC \| ISO 19115 \| Metadata \| Background \| Data Access Form \| Files

To work correctly, this web page requires that JavaScript be enabled in your browser. Please:
1) Enable JavaScript in your browser:
      • Chrome: "Settings : Advanced : Privacy and security : Site Settings : JavaScript"
      • Firefox: (it should be always on!)"
      • Opera: "Settings : Websites : JavaScript"
      • Safari: "Safari : Preferences : Security : Enable JavaScript"
2) Reload this web page.

Graph Type:
X Axis:
Y Axis:
Color:

Dimensions

Start

Stop

longitude (degrees_east)

latitude (degrees_north)

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 {
  longitude {
    String _CoordinateAxisType "Lon";
    Float64 actual_range 0.016666667535901077, 359.9833292646997;
    String axis "X";
    String ioos_category "Location";
    String long_name "Longitude";
    String standard_name "longitude";
    String units "degrees_east";
  }
  latitude {
    String _CoordinateAxisType "Lat";
    Float64 actual_range -90.0000035597249, 90.0000035597249;
    String axis "Y";
    String ioos_category "Location";
    String long_name "Latitude";
    String standard_name "latitude";
    String units "degrees_north";
  }
  uRe {
    String field "Re(u), scalar, amp=abs(uRe+i*uIm);GMT phase=atan2(-uIm,uRe)/pi*180;";
    String ioos_category "Currents";
    String long_name "Tidal West East Transport Complex Amplitude Real Part";
    String option_0 "land";
    String option_1 "~=0 - water";
    String units "centimeter^2/sec";
  }
  uIm {
    String field "Im(u), scalar, amp=abs(uRe+i*uIm);GMT phase=atan2(-uIm,uRe)/pi*180;";
    String ioos_category "Currents";
    String long_name "Tidal West East Transport Complex Amplitude Imaginary Part";
    String option_0 "land";
    String option_1 "~=0 - water";
    String units "centimeter^2/sec";
  }
  NC_GLOBAL {
    String cdm_data_type "Grid";
    String Conventions "COARDS, CF-1.10, ACDD-1.3";
    Float64 Easternmost_Easting 359.9833292646997;
    Float64 geospatial_lat_max 90.0000035597249;
    Float64 geospatial_lat_min -90.0000035597249;
    Float64 geospatial_lat_resolution 0.033333334651749966;
    String geospatial_lat_units "degrees_north";
    Float64 geospatial_lon_max 359.9833292646997;
    Float64 geospatial_lon_min 0.016666667535901077;
    Float64 geospatial_lon_resolution 0.03333333295649262;
    String geospatial_lon_units "degrees_east";
    String history 
"2026-06-06T01:11:46Z (local files)
2026-06-06T01:11:46Z https://erddap.cmcc-opa.eu/griddap/surf_osu_tpxo8_u_q1_30_v1.das";
    String infoUrl "https://www.tpxo.net/";
    String institution "Oregon State University";
    String keywords "current, eastward, imaginary, ocean, real, tidal, tide, transport, velocity";
    String license "Contact the data provider for redistribution and license terms.";
    Float64 Northernmost_Northing 90.0000035597249;
    String sourceUrl "(local files)";
    Float64 Southernmost_Northing -90.0000035597249;
    String summary "TPXO8 west-east tidal transport complex amplitude fields for constituent Q1 at 1/30-degree resolution.";
    String title "SURF | TPXO8 | U Transport Q1 1/30 Degree";
    String type "OTIS transport file";
    Float64 Westernmost_Easting 0.016666667535901077;
  }
}

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.