Data Access Form

Dataset Title:	Great Lakes Water Clarity-Turbidity Index, 2022-present
Institution:	NOAA/GLERL/COASTWATCH (Dataset ID: GL_Water_CTI_test)
Information:	Summary \| License \| FGDC \| ISO 19115 \| Metadata \| Background \| Files \| Make a graph

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.

Dimensions	Size	Spacing
time (UTC)	214	1 day 2h 55m 46s (uneven)

latitude (degrees_north)	1735	-0.0075 (even)

longitude (degrees_east)	2400	0.0075 (even)

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

CTI (clarity turbidity index)

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 {
    String _CoordinateAxisType "Time";
    Float64 actual_range 1.6944336e+9, 1.7150832e+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 37.99125, 50.99625;
    String axis "Y";
    String ioos_category "Location";
    String long_name "Latitude";
    String standard_name "latitude";
    String units "degrees_north";
  }
  longitude {
    String _CoordinateAxisType "Lon";
    Float32 actual_range -92.99625, -75.00375;
    String axis "X";
    String ioos_category "Location";
    String long_name "Longitude";
    String standard_name "longitude";
    String units "degrees_east";
  }
  CTI {
    String ioos_category "Unknown";
    String long_name "clarity turbidity index";
    String standard_name "clarity_turbidity_index";
  }
  NC_GLOBAL {
    String cdm_data_type "Grid";
    String Conventions "COARDS, CF-1.6, ACDD-1.3";
    String creator_email "cw.glerl@noaa.gov";
    String creator_name "NOAA/GLERL/COASTWATCH";
    String creator_type "institution";
    String creator_url "https://coastwatch.glerl.noaa.gov/";
    Float64 Easternmost_Easting -75.00375;
    Float64 geospatial_lat_max 50.99625;
    Float64 geospatial_lat_min 37.99125;
    Float64 geospatial_lat_resolution 0.0075000000000000015;
    String geospatial_lat_units "degrees_north";
    Float64 geospatial_lon_max -75.00375;
    Float64 geospatial_lon_min -92.99625;
    Float64 geospatial_lon_resolution 0.007500000000000003;
    String geospatial_lon_units "degrees_east";
    String grid_mapping__CoordinateAxisTypes "GeoX GeoY";
    String grid_mapping__CoordinateTransformType "Projection";
    String grid_mapping_horizontal_datum_name "World Geodetic System 1984";
    String grid_mapping_long_name "coordinate reference system";
    String grid_mapping_name "latitude_longitude";
    String grid_mapping_prime_meridian_name "Greenwich";
    String grid_mapping_reference_ellipsoid_name "WGS84";
    String history 
"VIIR NPP and N20 daily Merge, Normalized Water-leaving Radiance
2024-05-09T03:39:16Z (local files)
2024-05-09T03:39:16Z https://apps.glerl.noaa.gov/erddap/griddap/GL_Water_CTI_test.das";
    String infoUrl "https://coastwatch.glerl.noaa.gov/";
    String institution "NOAA/GLERL/COASTWATCH";
    String keywords "clarity, clarity_turbidity_index, coastwatch, CTI, data, environmental, glerl, great, index, laboratory, lakes, local, noaa, research, source, time, turbidity";
    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.";
    String map_projection "Geographic";
    Float64 Northernmost_Northing 50.99625;
    String source "VIIR NPP and N20 daily Merge, Normalized Water-leaving Radiance";
    String sourceUrl "(local files)";
    Float64 Southernmost_Northing 37.99125;
    String standard_name_vocabulary "CF Standard Name Table v70";
    String summary "Great Lakes Water Clarity-Turbidity Index, 2022-present";
    String testOutOfDate "now-3days";
    String time_coverage_end "2024-05-07T12:00:00Z";
    String time_coverage_start "2023-09-11T12:00:00Z";
    String title "Great Lakes Water Clarity-Turbidity Index, 2022-present";
    Float64 Westernmost_Easting -92.99625;
  }
}

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.