Global Data Assimilation System (GDAS)

The Global Data Assimilation System (GDAS) is the system used by the Global Forecast System (GFS) model to place observations into a gridded model space for the purpose of starting, or initializing, weather forecasts with observed data. GDAS adds the following types of observations to a gridded, 3-D, model space: surface observations, balloon data, wind profiler data, aircraft reports, buoy observations, radar observations, and satellite observations. GDAS data are available as both input observations to GDAS and gridded output fields from GDAS. Gridded GDAS output data can be used to start the GFS model. Due to the diverse nature of the assimilated data types, input data are available in a variety of data formats, primarily Binary Universal Form for the Representation of meteorological data (BUFR) and Institute of Electrical and Electronics Engineers (IEEE) binary. The GDAS output is World Meteorological Organization (WMO) Gridded Binary (GRIB).
Cite this dataset when used as a source.
  • NCEI DSI 6172
  • gov.noaa.ncdc:C00379
Download Data
Distribution Formats
  • GRIB 2 (Version: 2)
    • File Specification: http://www.nco.ncep.noaa.gov/pmb/docs/grib2/
Distributor Customer Engagement Branch
DOC/NOAA/NESDIS/NCEI > National Centers for Environmental Information, NESDIS, NOAA, U.S. Department of Commerce
1-828-271-4800
ncei.orders@noaa.gov
Dataset Point of Contact Customer Engagement Branch
DOC/NOAA/NESDIS/NCEI > National Centers for Environmental Information, NESDIS, NOAA, U.S. Department of Commerce
1-828-271-4800
ncei.orders@noaa.gov
Dataset Point of Contact DOC/NOAA/NESDIS/NCEI > National Centers for Environmental Information, NESDIS, NOAA, U.S. Department of Commerce
nomads.ncdc@noaa.gov
Coverage Description
Time Period 2001-01-01 to Present
Spatial Bounding Box Coordinates
N: 90.0
S: -90.0
E: 180.0
W: -180.0
Spatial Coverage Map
General Documentation
Publication Dates
  • publication: 2001-01-01
Data Presentation Form Digital model - multi-dimensional digital representation of a feature, process, etc.
Dataset Progress Status Ongoing - data is continually being updated
Data Update Frequency Daily
Purpose To provide initialization state grids for starting the Global Forecast System (GFS) model.
Cited Authors
  • DOC/NOAA/NWS/NCEP/EMC > Environmental Modeling Center, National Centers for Environmental Prediction, National Weather Service, NOAA, U.S. Department of Commerce
Originators
  • DOC/NOAA/NWS/NCEP/EMC > Environmental Modeling Center, National Centers for Environmental Prediction, National Weather Service, NOAA, U.S. Department of Commerce
Distributors
  • DOC/NOAA/NESDIS/NCEI > National Centers for Environmental Information, NESDIS, NOAA, U.S. Department of Commerce
Publishers
  • DOC/NOAA/NESDIS/NCEI > National Centers for Environmental Information, NESDIS, NOAA, U.S. Department of Commerce
Theme keywords Global Change Master Directory (GCMD) Science Keywords
  • Atmosphere > Altitude > Geopotential Height
  • Atmosphere > Altitude > Planetary Boundary Layer Height
  • Atmosphere > Altitude > Tropopause
  • Atmosphere > Atmospheric Pressure > Atmospheric Pressure Measurements
  • Atmosphere > Atmospheric Pressure > Pressure Thickness
  • Atmosphere > Atmospheric Pressure > Sea Level Pressure
  • Atmosphere > Atmospheric Pressure > Surface Pressure
  • Atmosphere > Atmospheric Pressure > Albedo
  • Atmosphere > Atmospheric Pressure > Land Cover
  • Atmosphere > Atmospheric Pressure > Soil Moisture/Water Content
  • Atmosphere > Atmospheric Pressure > Soil Temperature
  • Atmosphere > Atmospheric Pressure > Sea Surface Temperature
  • Atmosphere > Atmospheric Radiation > Albedo
  • Atmosphere > Atmospheric Radiation > Incoming Solar Radiation
  • Atmosphere > Atmospheric Radiation > Longwave Radiation
  • Atmosphere > Atmospheric Radiation > Radiative Flux
  • Atmosphere > Atmospheric Radiation > Shortwave Radiation
  • Atmosphere > Atmospheric Radiation > Solar Radiation
  • Earth Science > Atmosphere > Atmospheric Temperature > Surface Temperature > Air Temperature
  • Atmosphere > Atmospheric Temperature > Atmospheric Stability
  • Atmosphere > Atmospheric Temperature > Boundary Layer Temperature
  • Atmosphere > Atmospheric Temperature > Dew Point Temperature
  • Earth Science > Atmosphere > Atmospheric Temperature > Upper Air Temperature > Vertical Profiles > Inversion Height
  • Earth Science > Atmosphere > Atmospheric Temperature > Surface Temperature > Potential Temperature
  • Earth Science > Atmosphere > Atmospheric Temperature > Surface Temperature > Skin Temperature
  • Earth Science > Atmosphere > Atmospheric Temperature > Surface Temperature
  • Earth Science > Atmosphere > Atmospheric Temperature > Upper Air Temperature
  • Earth Science > Atmosphere > Atmospheric Water Vapor > Water Vapor Indicators > Dew Point Temperature
  • Earth Science > Atmosphere > Atmospheric Water Vapor > Water Vapor Processes > Evaporation
  • Earth Science > Atmosphere > Atmospheric Water Vapor > Water Vapor Indicators > Humidity
  • Earth Science > Atmosphere > Atmospheric Water Vapor > Water Vapor Indicators > Total Precipitable Water
  • Atmosphere > Atmospheric Water Vapor > Water Vapor
  • Atmosphere > Atmospheric Water Vapor > Water Vapor Profiles
  • Atmosphere > Atmospheric Winds > Boundary Layer Winds
  • Earth Science > Atmosphere > Atmospheric Winds > Wind Dynamics > Convection
  • Earth Science > Atmosphere > Atmospheric Winds > Upper Level Winds > Flight Level Winds
  • Atmosphere > Atmospheric Winds > Surface Winds
  • Atmosphere > Atmospheric Winds > Upper Level Winds
  • Earth Science > Atmosphere > Atmospheric Winds > Wind Dynamics > Vertical Wind Velocity/Speed
  • Earth Science > Atmosphere > Atmospheric Winds > Wind Dynamics > Vorticity
  • Atmosphere > Atmospheric Winds > Wind Profiles
  • Earth Science > Atmosphere > Atmospheric Winds > Wind Dynamics > Wind Shear
  • Atmosphere > Clouds > Tropospheric/High-Level Clouds (observed/Analyzed)
  • Atmosphere > Clouds > Tropospheric/Low Level Clouds (observed/Analyzed)
  • Atmosphere > Clouds > Tropospheric/Mid-Level Clouds (observed/Analyzed)
  • Earth Science > Atmosphere > Precipitation > Liquid Precipitation > Rain > Freezing Rain
  • Atmosphere > Precipitation > Precipitation Amount
  • Atmosphere > Precipitation > Precipitation Rate
  • Earth Science > Atmosphere > Precipitation > Liquid Precipitation > Rain
  • Earth Science > Atmosphere > Precipitation > Solid Precipitation > Ice Pellets > Sleet
  • Earth Science > Atmosphere > Precipitation > Solid Precipitation > Snow
  • Terrestrial Hydrosphere > Snow/Ice > Albedo
  • Terrestrial Hydrosphere > Snow/Ice > Snow Cover
  • Terrestrial Hydrosphere > Snow/Ice > Snow Depth
  • Oceans > Sea Ice > Sea Ice Concentration
  • Earth Science > Land Surface > Surface Radiative Properties > Albedo
  • Earth Science > Land Surface > Land Use/Land Cover > Land Use/Land Cover Classification > Vegetation Index
  • Land Surface > Soils > Soil Moisture/Water Content
  • Land Surface > Soils > Soil Temperature
  • Oceans > Ocean Temperature > Sea Surface Temperature
Data Center keywords Global Change Master Directory (GCMD) Data Center Keywords
  • DOC/NOAA/NESDIS/NCDC > National Climatic Data Center, NESDIS, NOAA, U.S. Department of Commerce
  • DOC/NOAA/NESDIS/NCEI > National Centers for Environmental Information, NESDIS, NOAA, U.S. Department of Commerce
Place keywords Global Change Master Directory (GCMD) Location Keywords
  • Geographic Region > Global
Project keywords Global Change Master Directory (GCMD) Project Keywords
  • NOMADS > The NOAA Operational Model Archive and Distribution System
Stratum keywords Global Change Master Directory (GCMD) Location Keywords
  • Vertical Location > Boundary Layer
  • Vertical Location > Land Surface
  • Vertical Location > Sea Surface
  • Vertical Location > Troposphere
  • Vertical Location > Stratosphere
Use Constraints No constraint information available
Fees
  • In most cases, electronic downloads of the data are free, however fees may apply for data certifications, copies of analog materials, and data distribution on physical media.
Lineage information for: repository
Processing Steps
  • 2015-04-22T00:00:00 - NOAA created the National Centers for Environmental Information (NCEI) by merging NOAA's National Climatic Data Center (NCDC), National Geophysical Data Center (NGDC), and National Oceanographic Data Center (NODC), including the National Coastal Data Development Center (NCDDC), per the Consolidated and Further Continuing Appropriations Act, 2015, Public Law 113-235. NCEI launched publicly on April 22, 2015.
Last Modified: 2018-05-25
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