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Dataset Title:  Chlorophyll, NOAA S-NPP VIIRS, Science Quality, U.S. East Coast 750m, Level 3,
2012-present, Annual
  RSS
Institution:  NOAA NESDIS CoastWatch East Coast Node   (Dataset ID: noaacwecnNPPVIIRSSQchlaEastCoastAnnual)
Information:  Summary ? | License ? | FGDC | ISO 19115 | Metadata | Background (external link) | Files | Make a graph
 
Dimensions ? Start ? Stride ? Stop ?  Size ?    Spacing ?
 time (UTC) ?      11    365 days 4h 35m 34s (uneven)
  < slider >
 level (Altitude, m) ?      1    (just one value)
  < slider >
 latitude (degrees_north) ?      3885    -0.006168588 (even)
  < slider >
 longitude (degrees_east) ?      4074    0.006168588 (even)
  < slider >
 
Grid Variables (which always also download all of the dimension variables) 
 chlor_a (Chlorophyll Concentration, OC3 Algorithm, mg m^-3) ?

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 1.34126427241e+9, 1.656789608904e+9;
    String axis "T";
    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";
  }
  level {
    Float64 actual_range 0.0, 0.0;
    String ioos_category "Location";
    String long_name "Altitude";
    String positive "up";
    String standard_name "altitude";
    String units "m";
  }
  latitude {
    String _CoordinateAxisType "Lat";
    Float64 actual_range 22.107128596152897, 46.0659239654323;
    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 -85.07597103632074, -59.95131255561142;
    String axis "X";
    String ioos_category "Location";
    String long_name "Longitude";
    String standard_name "longitude";
    String units "degrees_east";
  }
  chlor_a {
    UInt32 _ChunkSizes 1, 1, 512, 512;
    Float32 _FillValue NaN;
    String cell_methods "area: mean";
    Float64 colorBarMaximum 65.0;
    Float64 colorBarMinimum 0.01;
    String colorBarPalette "Rainbow";
    String colorBarScale "Log";
    String grid_mapping "coord_ref";
    String ioos_category "Ocean Color";
    String long_name "Chlorophyll Concentration, OC3 Algorithm";
    Float32 missing_value NaN;
    String standard_name "mass_concentration_of_chlorophyll_a_in_sea_water";
    String units "mg m^-3";
  }
  NC_GLOBAL {
    String cdm_data_type "Grid";
    String Conventions "CF-1.6, COARDS, ACDD-1.3";
    String creator_email "ronald.vogel at noaa.gov";
    String creator_name "NOAA CoastWatch East Coast Node";
    String creator_type "institution";
    String creator_url "https://eastcoast.coastwatch.noaa.gov";
    Float64 Easternmost_Easting -59.95131255561142;
    Float64 geospatial_lat_max 46.0659239654323;
    Float64 geospatial_lat_min 22.107128596152897;
    Float64 geospatial_lat_resolution 0.006168587891163594;
    String geospatial_lat_units "degrees_north";
    Float64 geospatial_lon_max -59.95131255561142;
    Float64 geospatial_lon_min -85.07597103632074;
    Float64 geospatial_lon_resolution 0.006168587891163593;
    String geospatial_lon_units "degrees_east";
    String history 
"2024-10-15T07:48:45Z (local files)
2024-10-15T07:48:45Z https://coastwatch.noaa.gov/erddap/griddap/noaacwecnNPPVIIRSSQchlaEastCoastAnnual.das";
    String infoUrl "https://eastcoast.coastwatch.noaa.gov/cw_viirs_chl.php";
    String institution "NOAA NESDIS CoastWatch East Coast Node";
    String instrument "Visible Infrared Imaging Radiometer Suite (VIIRS)";
    String keywords "chemistry, chl-a, chla, chlor, chlor-a, chlor_a, chlorophyll, chlorophyll-a, color, concentration, data, Earth Science > Oceans > Ocean Chemistry > Chlorophyll, Earth Science > Oceans > Ocean Optics > Ocean Color, image, imager, imager/radiometer, L3, level 3, level-3, mapped, ocean, ocean color, oceans, optical, polar-orbiting, radiance, radiometer, remote sensing, s-npp, satellite, sea, seasonal, seawater, snpp, VIIRS, viirs, visible, water, water quality";
    String keywords_vocabulary "NASA Global Change Master Directory (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, CoastWatch, NOAA, nor the US Government, nor any of their employees or contractors, make 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 46.0659239654323;
    String satellite "Suomi National Polar-orbiting Partnership (S-NPP)";
    String sourceUrl "(local files)";
    Float64 Southernmost_Northing 22.107128596152897;
    String standard_name_vocabulary "CF Standard Name Table v29";
    String summary "Annual average chlorophyll-a concentration for the U.S. East Coast from the VIIRS instrument aboard the S-NPP satellite, 2012-present, is produced using the blue-green reflectance ratio empirical approach of O'Reilly et al. (1998), adjusting the algorithm for the VIIRS spectral bands. Specifically, the algorithm is a 3-band algorithm (OC3V) whose inputs are the water-leaving radiance at wavelengths of 443, 486, and 551 nm (NOAA VIIRS ATBD, 2017). Atmospheric correction uses the near-infrared (NIR) approach of Jiang and Wang (2014), referred to as the BMW atmospheric correction. The individual overpasses are composited into daily mean grids (~840m), then the daily mean grids are averaged into annual gridded chlorophyll-a. More info: https://eastcoast.coastwatch.noaa.gov/cw_viirs_chl.php";
    String time_coverage_end "2022-07-02T19:20:08Z";
    String time_coverage_start "2012-07-02T21:24:32Z";
    String title "Chlorophyll, NOAA S-NPP VIIRS, Science Quality, U.S. East Coast 750m, Level 3, 2012-present, Annual";
    Float64 Westernmost_Easting -85.07597103632074;
  }
}

 

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.

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.


 

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