netcdf FROGs/MERRA2/pr_day_reanalysis_MERRA2_20170101-20171231.nc {
  dimensions:
    time = UNLIMITED;   // (365 currently)
    lon = 360;
    lat = 180;
  variables:
    double time(time=365);
      :standard_name = "time";
      :long_name = "time";
      :axis = "T";
      :comment = "The time values of the grid, following the standard CF calendar, in days, centred, since 1970-01-01 00:00:00";
      :units = "days since 1970-01-01";
      :calendar = "standard";
      :_ChunkSizes = 512U; // uint

    double lon(lon=360);
      :standard_name = "longitude";
      :long_name = "longitude";
      :units = "degrees_east";
      :axis = "X";
      :comment = "The longitude values of the grid, in degrees, ranging between [-179.5; 179.5]. The grid is centred, i.e., a value of +0.5 corresponds to the degree [0W, 1W]";

    double lat(lat=180);
      :standard_name = "latitude";
      :long_name = "latitude";
      :units = "degrees_north";
      :axis = "Y";
      :comment = "The latitude values of the grid, in degrees, ranging between [-89.5; 89.5]. The grid is centred, i.e., a value of +0.5 corresponds to the degree [0N, 1N]";

    float rain(time=365, lat=180, lon=360);
      :_FillValue = NaNf; // float
      :standard_name = "lwe_precipitation_rate";
      :long_name = "Precipitation accumulated from 0h to 0h";
      :units = "mm/day";
      :comment = "This daily precipitation is calculated from the reanalysis output prepared for CREATE-IP with averaging from 0.625 x 0.5 degree to 1 x 1 degree. This reanalysis is calculated by creating a daily mean of the source 6hr precipitation. Units have been converted from kg m-2 s-1 to mm/day (data*86400).";
      :missing_value = NaNf; // float
      :_ChunkSizes = 1U, 180U, 360U; // uint

  // global attributes:
  :Conventions = "ACDD-1.3, CF-1.8";
  :title = "Frogs daily 1 degree x 1 degree gridded precipitation for Modern-Era Retrospective analysis for Research and Applications, Version 2 (MERRA-2) Reanalysis";
  :summary = "The Frequent Rainfall Observations on GridS (FROGS) database (Roca et al., 2019) is composed of gridded daily-precipitation products on a common 1 degree x 1 degree grid to ease intercomparison and assessment exercises. The database includes satellite, ground-based and reanalysis products. As most of the satellite products rely on rain gauges for calibration, unadjusted versions of satellite products are also provided where available.     FROGS website homepage: http://frogs.ipsl.fr/";
  :references = "See https://www.earth-syst-sci-data.net/11/1017/2019. The reference paper for the FROGS database is the following:Roca, R., Alexander, L. V., Potter, G., Bador, M., Juca, R., Contractor, S., Bosilovich, M. G., and Cloche, S.: FROGS: a daily 1 degree x 1 degree gridded precipitation database of rain gauge, satellite and reanalysis products, Earth Syst. Sci. Data, 11, 1017-1035, https://doi.org/10.5194/essd-11-1017-2019.";
  :source = "Gridded Daily Accumulated Rainfall derived from MERRA-2 Reanalysis output prepared for CREATE-IP. Global Modeling and Assimilation Office (GMAO) (2015), MERRA-2 tavg1_2d_flx_Nx: 2d,1-Hourly,Time-Averaged,Single-Level,Assimilation,Surface Flux Diagnostics V5.12.4, Greenbelt, MD, USA, Goddard Earth Sciences Data and Information Services Center (GES DISC), 10.5067/7MCPBJ41Y0K6, Gelaro et al. 2017";
  :institution = "NASA-GMAO/LEGOS/IPSL";
  :comment = "This data set is an update of the FROGS v0 data set. Main differences are: - temporal extension from 2017 up to most recent data available if data available after 2017, - addition of two new data sets in the database : GPCC Full Data Daily version 2020 and PERSIANN-CCS-CDR, - metadata update.";
  :creator_name = "NASA-GMAO";
  :creator_email = "steven.pawson-1@nasa.gov";
  :creator_url = " http://gmao.gsfc.nasa.gov/reanalysis/merra-2/";
  :creator_type = "institution";
  :creator_institution = "Global Modeling and Assimilation Office, NASA Goddard Space Flight Center, Greenbelt, MD 20771";
  :contributor_name = "Remy Roca";
  :contributor_role = "data gridding and formatting in netCDF";
  :contributor_email = "remy.roca@legos.obs-mip.fr";
  :contributor_type = "person";
  :contributor_institution = "LEGOS";
  :metadata_link = "https://data.ipsl.fr/catalog/srv/eng/catalog.search#/metadata/20d37727-81b2-4821-9f51-6baa2b9cc06d";
  :id = "https://doi.org/10.14768/06337394-73A9-407C-9997-0E380DAC5598";
  :publisher_name = "ESPRI";
  :publisher_email = "none";
  :publisher_type = "institution";
  :publisher_url = "https://www.ipsl.fr/";
  :publisher_institution = "IPSL";
  :product_version = "1";
  :time_coverage_start = "2017-01-01T12:00:00";
  :time_coverage_end = "2017-12-31T12:00:00";
  :time_coverage_resolution = "day";
  :geospatial_lat_min = -89.5; // double
  :geospatial_lat_max = 89.5; // double
  :geospatial_lon_min = -179.5; // double
  :geospatial_lon_max = 179.5; // double
  :geospatial_lat_resolution = 1.0; // double
  :geospatial_lon_resolution = 1.0; // double
  :geospatial_lat_units = "degrees_north";
  :geospatial_lon_units = "degrees_east";
  :cdm_data_type = "grid";
  :keywords = "GCMD:EARTH SCIENCE,GCMD:ATMOSPHERE,GCMD:PRECIPITATION";
  :platform = "GCMD:Models/Analyses,GCMD:REANALYSIS MODELS";
  :instruments = "GCMD:In Situ/Laboratory Instruments,GCMD:Data Analysis";
  :instrument_vocabulary = "GCMD:GCMD Keywords";
  :platform_vocabulary = "GCMD:GCMD Keywords";
  :keywords_vocabulary = "GCMD:GCMD Keywords, CF:NetCDF COARDS Climate and Forecast Standard Names";
  :standard_name_vocabulary = "CF Standard Name Table v77";
}