Data Access Form

Dataset Title:	Temporal Trends, Primary Productivity, VIIRS S-NPP, MODIS Aqua, Global, 9km, 2013 to 2022.
Institution:	NOAA/NESDIS/STAR/CoastWatch/West Coast (Dataset ID: netpp_trends_viirssnpp_and_modisaqua)
Information:	Summary \| License \| FGDC \| ISO 19115 \| Metadata \| Background \| Files \| Make a graph

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Dimensions	Size	Spacing
latitude (degrees_north)	2160	-0.08333334 (uneven)

longitude (degrees_east)	4320	0.08333332 (uneven)

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

modis_beta (Slopes of MODIS Linear Regression, mg C m-2 d-1 y-1)

modis_pval (Level of Significance for the Slopes of the MODIS Linear Regression)

modis_n (Number of Observations Used for MODIS Linear Regression.)

viirs_beta (Slopes of Linear Regression for VIIRS Data, mg C m-2 d-1 y-1)

viirs_pval (Level of Significance for the Slopes of the VIIRS Linear Regression)

viirs_n (Number of Observations Used for the VIIRS Linear Regression.)

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 {
  latitude {
    String _CoordinateAxisType "Lat";
    Float64 actual_range -89.95834, 89.95834;
    String axis "Y";
    String coverage_content_type "coordinate";
    String ioos_category "Location";
    String long_name "Latitude";
    String standard_name "latitude";
    String units "degrees_north";
    Float64 valid_max 90.0;
    Float64 valid_min -90.0;
  }
  longitude {
    String _CoordinateAxisType "Lon";
    Float64 actual_range -179.9583, 179.9583;
    String axis "X";
    String coverage_content_type "coordinate";
    String ioos_category "Location";
    String long_name "Longitude";
    String standard_name "longitude";
    String units "degrees_east";
    Float64 valid_max 180.0;
    Float64 valid_min -180.0;
  }
  modis_beta {
    Float32 _FillValue -999.0;
    Float64 colorBarMaximum 25.0;
    Float64 colorBarMinimum -25.0;
    String colorBarPalette "RedWhiteBlue";
    String coverage_content_type "modelResult";
    String ioos_category "Other";
    String long_name "Slopes of MODIS Linear Regression";
    Float32 missing_value -999.0;
    String source "NOAA CoastWatch West Coast Node";
    String units "mg C m-2 d-1 y-1";
  }
  modis_pval {
    Float32 _FillValue -999.0;
    Float64 colorBarMaximum 1.0;
    Float64 colorBarMinimum 0.0;
    String colorBarPalette "KT_dense";
    String coverage_content_type "modelResult";
    String ioos_category "Other";
    String long_name "Level of Significance for the Slopes of the MODIS Linear Regression";
    Float32 missing_value -999.0;
    String source "NOAA CoastWatch West Coast Node";
  }
  modis_n {
    Float32 _FillValue -999.0;
    Float64 colorBarMaximum 120.0;
    Float64 colorBarMinimum 0.0;
    String colorBarPalette "KT_deep";
    String coverage_content_type "modelResult";
    String ioos_category "Other";
    String long_name "Number of Observations Used for MODIS Linear Regression.";
    Float32 missing_value -999.0;
    String source "NOAA CoastWatch West Coast Node";
    String standard_name "number_of_observations";
  }
  viirs_beta {
    Float32 _FillValue -999.0;
    Float64 colorBarMaximum 25.0;
    Float64 colorBarMinimum -25.0;
    String colorBarPalette "RedWhiteBlue";
    String coverage_content_type "modelResult";
    String ioos_category "Other";
    String long_name "Slopes of Linear Regression for VIIRS Data";
    Float32 missing_value -999.0;
    String source "NOAA CoastWatch West Coast Node";
    String units "mg C m-2 d-1 y-1";
  }
  viirs_pval {
    Float32 _FillValue -999.0;
    Float64 colorBarMaximum 1.0;
    Float64 colorBarMinimum 0.0;
    String colorBarPalette "KT_dense";
    String coverage_content_type "modelResult";
    String ioos_category "Other";
    String long_name "Level of Significance for the Slopes of the VIIRS Linear Regression";
    Float32 missing_value -999.0;
    String source "NOAA CoastWatch West Coast Node";
  }
  viirs_n {
    Float32 _FillValue -999.0;
    Float64 colorBarMaximum 120.0;
    Float64 colorBarMinimum 0.0;
    String colorBarPalette "KT_deep";
    String coverage_content_type "modelResult";
    String ioos_category "Other";
    String long_name "Number of Observations Used for the VIIRS Linear Regression.";
    Float32 missing_value -999.0;
    String source "NOAA CoastWatch West Coast Node";
    String standard_name "number_of_observations";
  }
  NC_GLOBAL {
    String acknowledgement "The project was supported by funding from the Portfolio Management Branch of NESDIS and NOAA CoastWatch.";
    String cdm_data_type "Grid";
    String contributor "Dale Robinson, Isaac Schroeder, Madison Richardson, Ryan Vandermeulen, Jonathan Sherman, Jesse Espinoza";
    String contributor_role "project management, development, production, development, development, production";
    String Conventions "CF-1.10, COARDS, ACDD-1.3";
    String creator_email "erd.data@noaa.gov";
    String creator_name "NOAA CoastWatch West Coast Node";
    String creator_type "institution";
    String creator_url "https://coastwatch.pfeg.noaa.gov/";
    String date_created "2025-04-09T09:07:56Z";
    Float64 Easternmost_Easting 179.9583;
    Float64 geospatial_lat_max 89.95834;
    Float64 geospatial_lat_min -89.95834;
    String geospatial_lat_units "degrees_north";
    Float64 geospatial_lon_max 179.9583;
    Float64 geospatial_lon_min -179.9583;
    String geospatial_lon_units "degrees_east";
    String history 
"Slope was calculated for each pixel location in the global grid from multi-year, monthly (9 km) primary productivity data. The probability that each slope was not different from zero was also determined. Calculations were run only on pixel timeseries where greater than 50% of the pixels contained data (50% of # of years times 12).
2025-05-01T12:59:31Z (local files)
2025-05-01T12:59:31Z https://coastwatch.pfeg.noaa.gov/wcn/erddap/griddap/netpp_trends_viirssnpp_and_modisaqua.das";
    String id "netpp_trends_viirssnpp_and_modisaqua";
    String infoUrl "https://coastwatch.pfeg.noaa.gov/";
    String institution "NOAA/NESDIS/STAR/CoastWatch/West Coast";
    String instrument "VIIRS, MODIS";
    String keywords "9km, active, aqua, aquatic, available, biosphere, chemistry, chlorophyll, coast, coastwatch, data, dynamics, earth, Earth Science > Biosphere > Ecological Dynamics > Ecosystem Functions > Primary Production, Earth Science > Biosphere > Ecosystems > Aquatic Ecosystems > Plankton > Phytoplankton, Earth Science > Oceans > Ocean Chemistry > Chlorophyll, Earth Science > Oceans > Ocean Optics > Photosynthetically Active Radiation, Earth Science > Oceans > Ocean Temperature > Sea Surface Temperature, ecological, ecosystem, ecosystems, environmental, functions, global, imager, imager/radiometer, imaging, information, infrared, latitude, level, linear, longitude, moderate, modis, modis_beta, modis_n, modis_pval, nasa, national, nesdis, noaa, npp, number, number_of_observations, observations, ocean, oceans, optics, orbiting, par, partnership, photosynthetically, phytoplankton, plankton, polar, polar-orbiting, primary, primary production, primary productivity, production, productivity, radiation, radiometer, regression, resolution, s-npp, satellite, science, sea, sea_surface_temperature, service, significance, slopes, spectroradiometer, sst, star, suite, surface, temperature, temporal, trends, used, viirs, viirs_beta, viirs_n, viirs_pval, visible, west, west coast node";
    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.";
    String map_projection "geographic";
    String naming_authority "gov.noaa.pfeg.coastwatch";
    Float64 Northernmost_Northing 89.95834;
    String platform "S-NPP, Aqua";
    String proj4_string "+proj=eqc +lat_ts=0 +lat_0=0 +x_0=0 +y_0=0 +ellps=WGS84 +datum=WGS84 +units=m +no_defs +lon_0=0.000000";
    String project "NOAA CoastWatch Interim Primary Productivity";
    String publisher_name "NOAA/NMFS/SWFSC/ERD, NOAA/NESDIS/STAR/CoastWatch/West Coast Node";
    String publisher_type "group";
    String publisher_url "https://coastwatch.pfeg.noaa.gov";
    String references "Melina et al. (2017) https://doi.org/10.1016/j.rse.2017.03.039, Behrenfeld and Falkowski (1997) https://doi.org/10.4319/lo.1997.42.1.0001";
    String source "S-NPP";
    String sourceUrl "(local files)";
    Float64 Southernmost_Northing -89.95834;
    String spatialResolution "9.28 km";
    String standard_name_vocabulary "CF Standard Name Table v70";
    String summary "Temporal trends for primary productivity derived for Visible and Infrared Imager/Radiometer Suite (VIIRS) S-National Polar-orbiting Partnership (NPP) and Moderate Resolution Imaging Spectroradiometer (MODIS) Aqua. Tends are reported as the slopes of linear regressions. Monthly, global primary productivity fields from January 2013 to December 2022 were derived from 9km chlorophyll, photosynthetically active radiation, and sea surface temperature data obtained from NASA. The number of observations and the level of significance (computed from a t-test) of the trends are also reported.";
    String time_coverage_resolution "P10Y";
    String title "Temporal Trends, Primary Productivity, VIIRS S-NPP, MODIS Aqua, Global, 9km, 2013 to 2022.";
    Float64 Westernmost_Easting -179.9583;
  }
}

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.