Data Access Form

Dataset Title:	Monthly Climatology MODIS Aqua Chlor_a
Institution:	CoastWatch, Carib. and GoM Regional Node, Atlantic OceanWatch (Dataset ID: GoMModisAquaMonthlyClimCHLOR)
Information:	Summary \| License \| FGDC \| ISO 19115 \| Metadata \| Background \| Make a graph

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Dimensions	Size	Spacing
time (UTC)	12	30 days 8h 43m 38s (uneven)

latitude (degrees_north)	432	0.04166667 (even)

longitude (degrees_east)	552	0.04166667 (even)

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

chlor_a (Chlorophyll Concentration, OCI Algorithm, mg m^-3)

Std_Dev_chlor_a (Chlorophyll Concentration standard deviation, mg m^-3)

Maximum_chlor_a (Chlorophyll Concentration Maximum, OCI Algorithm, mg m^-3)

Minimum_chlor_a (Chlorophyll Concentration Minimum, OCI Algorithm, mg m^-3)

File type: (more information)

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(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 1.0425888e+9, 1.0714464e+9;
    String axis "T";
    String calendar "Gregorian";
    String climatology "climatology_bounds";
    String CoordinateAxisType "Time";
    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";
    Float64 actual_range 15.020833333333334, 32.979166666666664;
    String axis "Y";
    String CoordinateAxisType "Lat";
    String ioos_category "Location";
    String long_name "Latitude";
    String standard_name "latitude";
    String units "degrees_north";
  }
  longitude {
    String _CoordinateAxisType "Lon";
    Float64 actual_range -100.97916666666667, -78.02083333333333;
    String axis "X";
    String CoordinateAxisType "Lon";
    String ioos_category "Location";
    String long_name "Longitude";
    String standard_name "longitude";
    String units "degrees_east";
  }
  chlor_a {
    Float32 _FillValue NaN;
    Float32 actual_range 0.0749, 93.4955;
    String cell_methods "time: mean within years time: mean over years";
    Float32 colorBarMaximum 10.0;
    Float32 colorBarMinimum 0.0;
    String coordsys "geographic";
    String ioos_category "Ocean Color";
    String long_name "Chlorophyll Concentration, OCI Algorithm";
    String reference "Hu, C., Lee Z., and Franz, B.A. (2012). Chlorophyll-a algorithms for oligotrophic oceans: A novel approach based on three-band reflectance difference, J. Geophys. Res., 117, C01011, doi:10.1029/2011JC007395.";
    String standard_name "mass_concentration_chlorophyll_concentration_in_sea_water";
    String units "mg m^-3";
    String variable_info "Aqua MODIS Monthly Chlorophyll Climatology in the Gulf of Mexico (2003-2015)";
  }
  Std_Dev_chlor_a {
    Float32 _FillValue NaN;
    Float32 actual_range 0.0012727922, 41.00483;
    Float32 colorBarMaximum 6.0;
    Float32 colorBarMinimum 0.0;
    String coordsys "geographic";
    String ioos_category "Statistics";
    String long_name "Chlorophyll Concentration standard deviation";
    String standard_name "mass_concentration_chlorophyll_concentration_in_sea_water";
    String units "mg m^-3";
    String variable_info "Standard_deviation Aqua MODIS Monthly Chlorophyll Climatology in the Gulf of Mexico (2003-2015)";
  }
  Maximum_chlor_a {
    Float32 _FillValue NaN;
    Float32 actual_range 0.0749, 99.9009;
    String cell_methods "time: maximum within years time: maximum over years";
    Float32 colorBarMaximum 10.0;
    Float32 colorBarMinimum 0.0;
    String coordsys "geographic";
    String ioos_category "Ocean Color";
    String long_name "Chlorophyll Concentration Maximum, OCI Algorithm";
    String standard_name "mass_concentration_chlorophyll_concentration_in_sea_water";
    String units "mg m^-3";
    String variable_info "Maximum Aqua MODIS Monthly Chlorophyll Climatology in the Gulf of Mexico (2003-2015)";
  }
  Minimum_chlor_a {
    Float32 _FillValue NaN;
    Float32 actual_range 0.02, 93.4955;
    String cell_methods "time: minimum within years time: minimum over years";
    Float32 colorBarMaximum 10.0;
    Float32 colorBarMinimum 0.0;
    String coordsys "geographic";
    String ioos_category "Ocean Color";
    String long_name "Chlorophyll Concentration Minimum, OCI Algorithm";
    String standard_name "mass_concentration_chlorophyll_concentration_in_sea_water";
    String units "mg m^-3";
    String variable_info "Minimum Aqua MODIS Monthly Chlorophyll Climatology in the Gulf of Mexico (2003-2015)";
  }
  NC_GLOBAL {
    String cdm_data_type "Grid";
    String comment "Monthly Chlor_a Climatology in the Gulf of Mexico (2003-2015)";
    String contact "Joaquin.Trinanes@noaa.gov";
    String Conventions "COARDS, CF-1.0, Unidata Dataset Discovery v1.0";
    String creator_email "Joaquin.Trinanes@noaa.gov";
    String creator_name "NOAA/AOML/Atlantic OceanWatch";
    String creator_url "https://www.aoml.noaa.gov/phod/";
    String data_source "USDOC/NOAA/OAR/AOML/PHOD";
    Float64 Easternmost_Easting -78.02083333333333;
    Float64 geospatial_lat_max 32.979166666666664;
    Float64 geospatial_lat_min 15.020833333333334;
    Float64 geospatial_lat_resolution 0.04166666666666666;
    String geospatial_lat_units "degrees_north";
    Float64 geospatial_lon_max -78.02083333333333;
    Float64 geospatial_lon_min -100.97916666666667;
    Float64 geospatial_lon_resolution 0.041666666666666685;
    String geospatial_lon_units "degrees_east";
    String history 
"2024-04-23T11:52:21Z https://cwcgom.aoml.noaa.gov/thredds/dodsC/AQUA_CHLOR_GULF_MONTHLY_CLIM/aquachlormonthlyclim.nc
2024-04-23T11:52:21Z http://cwcgom.aoml.noaa.gov:8080/erddap/griddap/GoMModisAquaMonthlyClimCHLOR.das";
    String infoUrl "http://cwcaribbean.aoml.noaa.gov";
    String institution "CoastWatch, Carib. and GoM Regional Node, Atlantic OceanWatch";
    String keywords "aqua, chlorophyll, Gulf of Mexico, modis, monthly climatology";
    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.";
    Int32 nco_openmp_thread_number 1;
    Int32 node_offset 0;
    Float64 Northernmost_Northing 32.979166666666664;
    String origin "USDOC/NOAA/OAR/AOML/PHOD";
    String source_data "Ocean Biology Processing Group (NASA/GSFC/OBPG)";
    String sourceUrl "https://cwcgom.aoml.noaa.gov/thredds/dodsC/AQUA_CHLOR_GULF_MONTHLY_CLIM/aquachlormonthlyclim.nc";
    Float64 Southernmost_Northing 15.020833333333334;
    String spatial_resolution "0.041666 degree";
    String standard_name_vocabulary "CF-1.0";
    String summary "TBD";
    String time_coverage_end "2003-12-15T00:00:00Z";
    String time_coverage_start "2003-01-15T00:00:00Z";
    String title "Monthly Climatology MODIS Aqua Chlor_a";
    Float64 Westernmost_Easting -100.97916666666667;
  }
}

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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.