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Dataset Title:  Sea Ice Concentration, NOAA/NSIDC Climate Data Record V4, Northern Hemisphere,
25km, Science Quality, 1978-Present, Daily
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Institution:  NSIDC > National Snow and Ice Data Center   (Dataset ID: nsidcG02202v4nh1day)
Information:  Summary ? | License ? | Metadata | Background (external link) | Files | Make a graph
 
Dimensions ? Start ? Stride ? Stop ?  Size ?    Spacing ?
 time (UTC) ?      16598    1 day 0h 7m 38s (uneven)
  < slider >
 ygrid (meters) ?      448    -25000.0 (even)
  < slider >
 xgrid (meters) ?      304    25000.0 (even)
  < slider >
 
Grid Variables (which always also download all of the dimension variables) 
 cdr_seaice_conc (1) ?
 melt_onset_day_cdr_seaice_conc (1) ?
 nsidc_bt_seaice_conc (1) ?
 nsidc_nt_seaice_conc (1) ?
 qa_of_cdr_seaice_conc ?
 spatial_interpolation_flag ?
 stdev_of_cdr_seaice_conc ?
 temporal_interpolation_flag ?

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 {
    UInt32 _ChunkSizes 1024;
    String _CoordinateAxisType "Time";
    Float64 actual_range 2.781216e+8, 1.7197056e+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";
  }
  ygrid {
    UInt32 _ChunkSizes 448;
    Float32 actual_range -5337500.0, 5837500.0;
    String axis "Y";
    String ioos_category "Location";
    String long_name "projection_grid_y_centers";
    String standard_name "projection_y_coordinate";
    String units "meters";
    Float32 valid_range -5350000.0, 5850000.0;
  }
  xgrid {
    UInt32 _ChunkSizes 304;
    Float32 actual_range -3837500.0, 3737500.0;
    String axis "X";
    String ioos_category "Location";
    String long_name "projection_grid_x_centers";
    String standard_name "projection_x_coordinate";
    String units "meters";
    Float32 valid_range -3850000.0, 3750000.0;
  }
  cdr_seaice_conc {
    Float32 _FillValue 2.54;
    String ancillary_variables "stdev_of_cdr_seaice_conc qa_of_cdr_seaice_conc";
    Float64 colorBarMaximum 1.0;
    Float64 colorBarMinimum 0.0;
    String colorBarPalette "KT_ice";
    String datum "+ellps=urn:ogc:def:crs:EPSG::4326";
    String flag_meanings "pole_hole lakes coastal land_mask missing_data";
    Byte flag_values -5, -4, -3, -2, -1;
    String ioos_category "Ice Distribution";
    String long_name "NOAA/NSIDC Climate Data Record of Passive Microwave Daily Northern Hemisphere Sea Ice Concentration";
    String references "https://nsidc.org/data/g02202/versions/4/";
    String standard_name "sea_ice_area_fraction";
    String units "1";
    Float32 valid_range 0.0, 1.0;
  }
  melt_onset_day_cdr_seaice_conc {
    Byte _FillValue -1;
    String _Unsigned "true";
    Float64 colorBarMaximum 250.0;
    Float64 colorBarMinimum 50.0;
    String datum "+ellps=urn:ogc:def:crs:EPSG::4326";
    String ioos_category "Ice Distribution";
    String long_name "Day of Snow Melt Onset Over Sea Ice";
    Byte missing_value -1;
    String units "1";
    Byte valid_range 60, -12;
  }
  nsidc_bt_seaice_conc {
    Float32 _FillValue 2.54;
    Float64 colorBarMaximum 1.0;
    Float64 colorBarMinimum 0.0;
    String colorBarPalette "KT_ice";
    String datum "+ellps=urn:ogc:def:crs:EPSG::4326";
    String flag_meanings "pole_hole unused coastal land_mask missing_data";
    Byte flag_values -5, -4, -3, -2, -1;
    String ioos_category "Ice Distribution";
    String long_name "Passive Microwave Daily Northern Hemisphere Sea Ice Concentration by Bootstrap algorithm processed by NSIDC";
    String standard_name "sea_ice_area_fraction";
    String units "1";
    Float32 valid_range 0.0, 1.0;
  }
  nsidc_nt_seaice_conc {
    Float32 _FillValue 2.54;
    Float64 colorBarMaximum 1.0;
    Float64 colorBarMinimum 0.0;
    String colorBarPalette "KT_ice";
    String datum "+ellps=urn:ogc:def:crs:EPSG::4326";
    String flag_meanings "pole_hole unused coastal land_mask missing_data";
    Byte flag_values -5, -4, -3, -2, -1;
    String ioos_category "Ice Distribution";
    String long_name "Passive Microwave Daily Northern Hemisphere Sea Ice Concentration by NASA Team algorithm processed by NSIDC";
    String standard_name "sea_ice_area_fraction";
    String units "1";
    Float32 valid_range 0.0, 1.0;
  }
  qa_of_cdr_seaice_conc {
    Byte _FillValue 0;
    String _Unsigned "true";
    Float64 colorBarMaximum 64.0;
    Float64 colorBarMinimum 0.0;
    String colorBarPalette "KT_amp";
    String datum "+ellps=urn:ogc:def:crs:EPSG::4326";
    String flag_mask_meanings "BT_weather_filter_applied NT_weather_filter_applied BT_land_spillover_filter_applied NT_land_spillover_filter_applied valid_ice_mask_applied spatial_interpolation_applied temporal_interpolation_applied melt_start_detected";
    Byte flag_masks 1, 2, 4, 8, 16, 32, 64, -128;
    String ioos_category "Quality";
    String long_name "Passive Microwave Daily Northern Hemisphere Sea Ice Concentration QC flags";
    Byte missing_value 0;
    String standard_name "sea_ice_area_fraction status_flag";
    Byte valid_range 1, -1;
  }
  spatial_interpolation_flag {
    Byte _FillValue 0;
    String _Unsigned "true";
    Float64 colorBarMaximum 32.0;
    Float64 colorBarMinimum 0.0;
    String colorBarPalette "KT_amp";
    String datum "+ellps=urn:ogc:def:crs:EPSG::4326";
    Byte flag_masks 1, 2, 4, 8, 16, 32;
    String flag_meanings "19v_tb_value_interpolated 19h_tb_value_interpolated 22v_tb_value_interpolated 37v_tb_value_interpolated 37h_tb_value_interpolated pole_hole_value_interpolated";
    String ioos_category "Quality";
    String long_name "Passive Microwave Daily Northern Hemisphere Sea Ice Concentration spatial interpolation flags";
    Byte missing_value 0;
    String standard_name "interpolation_flag";
    Byte valid_range 0, 63;
  }
  stdev_of_cdr_seaice_conc {
    Float32 _FillValue -1.0;
    Float64 colorBarMaximum 5.0;
    Float64 colorBarMinimum 0.0;
    String colorBarPalette "KT_amp";
    String datum "+ellps=urn:ogc:def:crs:EPSG::4326";
    String flag_meanings "pole_hole lakes coastal land_mask missing_data";
    Byte flag_values -5, -4, -3, -2, -1;
    String ioos_category "Statistics";
    String long_name "Passive Microwave Daily Northern Hemisphere Sea Ice Concentration Source Estimated Standard Deviation";
    Float32 missing_value -1.0;
    Float32 valid_range 0.0, 100.0;
  }
  temporal_interpolation_flag {
    Byte _FillValue 0;
    String _Unsigned "true";
    Float64 colorBarMaximum 60.0;
    Float64 colorBarMinimum 0.0;
    String colorBarPalette "KT_amp";
    String comment "If flagged, the value has been replaced by the value n-days prior, n-days following, or the mean of n-days prior and following where n is 1, 2, 3, 4, or 5 days.";
    String datum "+ellps=urn:ogc:def:crs:EPSG::4326";
    Byte flag_masks 1, 2, 3, 4, 5, 10, 11, 20, 22, 30, 33, 40, 44, 50, 55;
    String flag_meanings "1_day_following 2_days_following 3_days_following 4_days_following 5_days_following 1_day_prior mean_of_prior_and_following_1_day 2_days_prior mean_of_prior_and_following_2_days 3_days_prior mean_of_prior_and_following_3_days 4_days_prior mean_of_prior_and_following_4_days 5_days_prior mean_of_prior_and_following_5_days";
    String ioos_category "Quality";
    String long_name "Passive Microwave Daily Northern Hemisphere Sea Ice Concentration temporal interpolation flags";
    Byte missing_value 0;
    String standard_name "interpolation_flag";
    Byte valid_range 0, 55;
  }
  NC_GLOBAL {
    String _NCProperties "version=2,netcdf=4.8.1,hdf5=1.10.6";
    String acknowledgement "This project was supported in part by a grant from the NOAA Climate Data Record Program. Production of original NASA Team and Bootstrap algorithm estimates supported by the NASA Polar Distributed Active Archive Center. The sea ice concentration algorithms were developed by Donald J. Cavalieri, Josefino C. Comiso, Claire L. Parkinson, and others at the NASA Goddard Space Flight Center in Greenbelt, MD.";
    String cdm_data_type "Grid";
    String cdr_variable "cdr_seaice_conc";
    String contributor_name "Walter N. Meier, Florence Fetterer, Ann Windnagel, J. Scott Stewart, Trey Stafford, Matt Fisher";
    String contributor_role "principal investigator, author, author, software developer, software developer, software developer";
    String Conventions "CF-1.6, ACDD-1.3, COARDS";
    String creator_email "nsidc@nsidc.org";
    String creator_name "NSIDC";
    String creator_type "institution";
    String creator_url "https://nsidc.org/";
    String date_created "2024-10-29T16:08:15Z";
    String defaultGraphQuery "cdr_seaice_conc[last]%5B(-5337500.0)%5D%5B(3737500.0)%5D&.draw=surface";
    Float64 grid_mapping_false_easting 0.0;
    Float64 grid_mapping_false_northing 0.0;
    String grid_mapping_GeoTransform "-3850000.0 25000.0 0 5850000.0 0 -25000.0";
    Float64 grid_mapping_grid_boundary_bottom_projected_y -5350000.0;
    Float64 grid_mapping_grid_boundary_left_projected_x -3850000.0;
    Float64 grid_mapping_grid_boundary_right_projected_x 3750000.0;
    Float64 grid_mapping_grid_boundary_top_projected_y 5850000.0;
    Float64 grid_mapping_latitude_of_projection_origin 90.0;
    Float64 grid_mapping_longitude_of_projection_origin -45.0;
    String grid_mapping_name "polar_stereographic";
    Float64 grid_mapping_parent_grid_cell_column_subset_end 304.0;
    Float64 grid_mapping_parent_grid_cell_column_subset_start 0.0;
    Float64 grid_mapping_parent_grid_cell_row_subset_end 448.0;
    Float64 grid_mapping_parent_grid_cell_row_subset_start 0.0;
    String grid_mapping_proj4text "+proj=stere +lat_0=90 +lat_ts=70 +lon_0=-45 +k=1 +x_0=0 +y_0=0 +a=6378273 +b=6356889.449 +units=m +no_defs";
    Float64 grid_mapping_scaling_factor 1.0;
    Float64 grid_mapping_semimajor_radius 6378273.0;
    Float64 grid_mapping_semiminor_radius 6356889.449;
    String grid_mapping_spatial_ref "PROJCS[\"NSIDC Sea Ice Polar Stereographic North\",GEOGCS[\"Unspecified datum based upon the Hughes 1980 ellipsoid\",DATUM[\"Not_specified_based_on_Hughes_1980_ellipsoid\",SPHEROID[\"Hughes 1980\",6378273,298.279411123061,AUTHORITY[\"EPSG\",\"7058\"]],AUTHORITY[\"EPSG\",\"6054\"]],PRIMEM[\"Greenwich\",0,AUTHORITY[\"EPSG\",\"8901\"]],UNIT[\"degree\",0.01745329251994328,AUTHORITY[\"EPSG\",\"9122\"]],AUTHORITY[\"EPSG\",\"4054\"]],UNIT[\"metre\",1,AUTHORITY[\"EPSG\",\"9001\"]],PROJECTION[\"Polar_Stereographic\"],PARAMETER[\"latitude_of_origin\",70],PARAMETER[\"central_meridian\",-45],PARAMETER[\"scale_factor\",1],PARAMETER[\"false_easting\",0],PARAMETER[\"false_northing\",0],AUTHORITY[\"EPSG\",\"3411\"],AXIS[\"X\",UNKNOWN],AXIS[\"Y\",UNKNOWN]]";
    String grid_mapping_srid "urn:ogc:def:crs:EPSG::3411";
    Float64 grid_mapping_standard_parallel 70.0;
    Float64 grid_mapping_straight_vertical_longitude_from_pole 135.0;
    String grid_mapping_units "meters";
    String history 
"Generated from NSIDC0001
2024-12-03T15:28:30Z (local files)
2024-12-03T15:28:30Z https://polarwatch.noaa.gov/erddap/griddap/nsidcG02202v4nh1day.das";
    String id "https://doi.org/10.7265/sr8p-kc62";
    String infoUrl "https://nsidc.org/";
    String institution "NSIDC > National Snow and Ice Data Center";
    String keywords "algorithm, america, arctic, area, atlantic, barents, bay, beaufort, bering, bootstrap, canada, cdr_seaice_conc, center, chukchi, climate, common, concentration, continent, CONTINENT > NORTH AMERICA > CANADA > HUDSON BAY, Continent > North America > Canada > Hudson Bay, cryosphere, daily, data, davis, day, defense, deviation, distribution, dmsp, earth, Earth Science > Cryosphere > Sea Ice > Ice Extent, Earth Science > Cryosphere > Sea Ice > Sea Ice Concentration, Earth Science > Oceans > Sea Ice > Ice Extent, estimated, extent, flag, flags, flight, format, fraction, geographic, Geographic Region > Arctic, Geographic Region > Northern Hemisphere, Geographic Region > Polar, goddard, gsfc, gulf, hemisphere, hudson, ice, ice distribution, interpolation, interpolation_flag, lawrence, mayen, melt, melt_onset_day_cdr_seaice_conc, meteorological, microwave, nasa, national, network, noaa, noaa/nsidc, north, northern, norwegian, nsidc, nsidc_bt_seaice_conc, nsidc_nt_seaice_conc, ocean, Ocean > Arctic Ocean, Ocean > Arctic Ocean > Barents Sea, Ocean > Arctic Ocean > Beaufort Sea, Ocean > Arctic Ocean > Chukchi Sea, Ocean > Atlantic Ocean > North Atlantic Ocean > Davis Straight, OCEAN > ATLANTIC OCEAN > NORTH ATLANTIC OCEAN > GULF OF ST LAWRENCE, Ocean > Atlantic Ocean > North Atlantic Ocean > North Sea, Ocean > Atlantic Ocean > North Atlantic Ocean > Norwegian Sea, OCEAN > ATLANTIC OCEAN > NORTH ATLANTIC OCEAN > SVALBARD AND JAN MAYEN, Ocean > Pacific Ocean, Ocean > Pacific Ocean > North Pacific Ocean > Bering Sea, Ocean > Pacific Ocean > North Pacific Ocean > Sea Of Okhotsk, oceans, okhotsk, onset, over, pacific, passive, polar, processed, program, qa_of_cdr_seaice_conc, quality, record, region, satellite, science, sea, sea_ice_area_fraction, sea_ice_area_fraction status_flag, snow, source, space, spatial, spatial_interpolation_flag, standard, statistics, status, stdev_of_cdr_seaice_conc, straight, svalbard, tdim, team, temporal, temporal_interpolation_flag, version";
    String keywords_vocabulary "GCMD Science Keywords";
    String license "No constraints on data access or use";
    String metadata_Link "https://nsidc.org/data/g02202/versions/4/";
    String naming_authority "org.doi.dx";
    String platform "DMSP 5D-3/F17 > Defense Meteorological Satellite Program-F17";
    String processing_level "NOAA Level 3";
    String product_version "v04r00";
    String program "NOAA Climate Data Record Program";
    String proj_crs_code "EPSG:3411";
    String proj_crs_code_description "The proj_crs_code attribute references a registered projection identifier (i.e. EPSG) when available. If the projection is not registered, non-standard then this attribute references a PolarWatch assigned internal identifier.";
    String project "NOAA/NSIDC passive microwave sea ice concentration climate data record";
    String references "Comiso, J. C., and F. Nishio. 2008. Trends in the Sea Ice Cover Using Enhanced and Compatible AMSR-E, SSM/I, and SMMR Data. Journal of Geophysical Research 113, C02S07, doi:10.1029/2007JC0043257. ; Comiso, J. C., D. Cavalieri, C. Parkinson, and P. Gloersen. 1997. Passive Microwave Algorithms for Sea Ice Concentrations: A Comparison of Two Techniques. Remote Sensing of the Environment 60(3):357-84. ; Comiso, J. C. 1984. Characteristics of Winter Sea Ice from Satellite Multispectral Microwave Observations. Journal of Geophysical Research 91(C1):975-94. ; Cavalieri, D. J., P. Gloersen, and W. J. Campbell. 1984. Determination of Sea Ice Parameters with the NIMBUS-7 SMMR. Journal of Geophysical Research 89(D4):5355-5369. ; Cavalieri, D. J., C. l. Parkinson, P. Gloersen, J. C. Comiso, and H. J. Zwally. 1999. Deriving Long-term Time Series of Sea Ice Cover from Satellite Passive-Microwave Multisensor Data Sets. Journal of Geophysical Research 104(7): 15,803-15,814 ; Comiso, J.C., R.A. Gersten, L.V. Stock, J. Turner, G.J. Perez, and K. Cho. 2017. Positive Trend in the Antarctic Sea Ice Cover and Associated Changes in Surface Temperature. J. Climate, 30, 2251–2267, https://doi.org/10.1175/JCLI-D-16-0408.1";
    String sensor "SSMI/S > Special Sensor Microwave Imager/Sounder";
    String software_version_id "git@bitbucket.org:nsidc/seaice_cdr.git@22aac63463cb6013d2a29279c81d130e1f1b0403";
    String source "Generated from NSIDC0001";
    String sourceUrl "(local files)";
    String spatial_resolution "25km";
    String standard_name_vocabulary "CF Standard Name Table v70";
    String summary "This data set provides a passive microwave sea ice concentration climate data record (CDR) based on gridded brightness temperatures (TBs) from the Defense Meteorological Satellite Program (DMSP) series of passive microwave radiometers: the Nimbus-7 Scanning Multichannel Microwave Radiometer (SMMR), the Special Sensor Microwave Imager (SSM/I) and the Special Sensor Microwave Imager/Sounder (SSMIS). The sea ice concentration CDR is an estimate of sea ice concentration that is produced by combining concentration estimates from two algorithms developed at the NASA Goddard Space Flight Center (GSFC): the NASA Team algorithm and the Bootstrap algorithm. The individual algorithms are used to process and combine brightness temperature data at National Snow and Ice Data Center (NSIDC). This product is designed to provide a consistent time series of sea ice concentrations (the fraction, or percentage, of ocean area covered by sea ice) from November 1978 to the present which spans the coverage of several passive microwave instruments. The data are gridded on the NSIDC polar stereographic grid with 25 x 25 km grid cells, and are available in Network Common Data Format (NetCDF) file format. Each file contains a variable with the CDR concentration values as well as variables that hold the NASA Team and Bootstrap processed concentrations for reference Variables containing standard deviation, quality flags, and projection information are also included. Data are available from NSIDC via FTP see https://nsidc.org/data/G02202/versions/4/. Data are also distributed via the PolarWatch ERDDAP at https://polarwatch.noaa.gov/erddap. Note that the data format available through PolarWatch is different from the NSIDC FTP NetCDF files. The PolarWatch data server stores projection information as global attributes (with the prefix grid_mapping) instead of as a variable; and the timestamp is served in different units (seconds since 1970).";
    String time_coverage_duration "P1D";
    String time_coverage_end "2024-06-30T00:00:00Z";
    String time_coverage_resolution "P1D";
    String time_coverage_start "1978-10-25T00:00:00Z";
    String title "Sea Ice Concentration, NOAA/NSIDC Climate Data Record V4, Northern Hemisphere, 25km, Science Quality, 1978-Present, Daily";
  }
}

 

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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