One degree Global Data Assimilation System Data from NOAA/NCEP

Metadata Updated: April 30, 2019

The National Weather Service's National Centers for Environmental Prediction (NCEP) runs a series of computer analyses and forecasts operationally. One of the operational systems is the Global Data Assimilation System (GDAS, Kanamitsu, 1989), which uses the spectral Medium Range Forecast model (MRF) for the forecast. Another system is the Eta Data Assimilation System (EDAS), covering the U.S.

  At NOAA's Air Resources Laboratory (ARL), NCEP model output is
  used for air quality transport and dispersion modeling. ARL
  archives both EDAS and GDAS data using a 1-byte packing
  method. Both archives contain basic fields such as the u- and
  v-wind components, temperature, and humidity. However, the
  archives differ from each other because of the horizontal and
  vertical resolution, as well as in the specific fields, provided
  by NCEP.


  The 6-hourly archive data come from NCEP's GDAS.  The GDAS is
  the final run in the series of NCEP operational model runs; it
  therefore is known as the Final Run at NCEP and includes late
  arriving conventional and satellite data. It is run 4 times a
  day, ie, at 00, 06, 12, and 18 UTC.  Model output is for the
  analysis time and a 6-hour forecast. Some fields such as
  precipitation and surface fluxes are only available at the
  forecast time. Details of the GDAS are described by Kanamitsu
  (1989), Derber et al. (1991), and Parrish and Derber (1992).

  NCEP post-processing of the GDAS converts the data from spectral
  coefficient form to 1 degree latitude-longitude (360 by 181)
  grids and from sigma levels to mandatory pressure levels.
  Surface and upper level FNL data are output on the following
  mandatory pressure surfaces: 1000, 925, 850, 700, 500, 400, 300,
  250, 200, 150, 100, 50, and 20 hPa. These data are written to
  the NIC (NOAA Information Center) FTP server (
  in GRIB (GRIdded Binary) format

  Data set information:

Access & Use Information

Public: This dataset is intended for public access and use. License: No license information was provided. If this work was prepared by an officer or employee of the United States government as part of that person's official duties it is considered a U.S. Government Work.

Downloads & Resources


Metadata Created Date February 28, 2019
Metadata Updated Date April 30, 2019

Metadata Source

Harvested from NASA Data.json

Additional Metadata

Resource Type Dataset
Metadata Created Date February 28, 2019
Metadata Updated Date April 30, 2019
Unique Identifier C1558374418-LAADS
Maintainer Email
Public Access Level public
Bureau Code 026:00
Metadata Context
Metadata Catalog ID
Schema Version
Catalog Describedby
Citation NASA, NOAA/NCEP. One degree Global Data Assimilation System Data from NOAA/NCEP (MODIS Ancillary Data). Version 6. Archived by National Aeronautics and Space Administration, U.S. Government, NASA/GSFC/SED/ESD/HBSL/BISB/LAADS.
Harvest Object Id a1602208-35fd-431c-b678-24d48aa123e8
Harvest Source Id 39e4ad2a-47ca-4507-8258-852babd0fd99
Harvest Source Title NASA Data.json
Data First Published 2000-02-23
Homepage URL
Language en-US
Metadata Type geospatial
Data Last Modified 2018-10-10
Program Code 026:001
Source Datajson Identifier True
Source Hash ce0d6b98c6371a83493c94756c6cfae24d04195b
Source Schema Version 1.1
Spatial -180.0 -90.0 180.0 90.0
Temporal 2000-02-23T00:00:00Z/2019-04-29T00:00:00Z
Category AQUA, TERRA, geospatial

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