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Restrictions | Details | Caveats | File Naming | Citation | References | Original Source | Contact

NCEP Global Ocean Data Assimilation System (GODAS)

Brief Description:

Temporal Coverage:

  • Monthly values for 1980/01 - 2014/09 .

Spatial Coverage:

  • 0.333 degree latitude x 1.0 degree longitude global grid (418x360).
  • 74.5S - 64.5N, 0.5E - 359.5E.
  • 74.0S - 65.0N, 1.0E - 360.0E.

Levels:

  • 5, 15, 25, 35, 45, 55, 65, 75, 85, 95, 105, 115, 125, 135, 145, 155, 165, 175, 185, 195, 205, 215, 225, 238, 262, 303, 366, 459, 584, 747, 949, 1193, 1479, 1807, 2174, 2579, 3016, 3483, 3972, 4478 m depth.
  • 10, 20, 30, 40, 50, 60, 70, 80, 90, 100, 110, 120, 130, 140, 150, 160, 170, 180, 190, 200, 210, 220, 231, 250, 282, 334, 412, 521, 665, 848, 1071, 1336, 1643, 1990, 2376, 2797, 3249, 3727, 4225, 4736 m depth (for geometric vertical velocity only).
  • Sea Surface

Update Schedule:

  • Static

Download/Plot Data:

Variable Statistic Level Download File Create Plot/Subset
Total downward heat flux at surface Monthly Mean Surface List of thflx.*.nc files plot
Salt Flux Monthly Mean Surface List of sltfl.*.nc files plot
Sea Surface Height Relative to Geoid Monthly Mean Surface List of sshg.*.nc files plot
Geometric Depth Below Sea Surface Monthly Mean Isothermal Layer List of dbss_obil.*.nc files plot
Geometric Depth Below Sea Surface Monthly Mean Mixing Layer List of dbss_obml.*.nc files plot
Momentum flux, u component Monthly Mean Surface List of uflx.*.nc files plot
Momentum flux, v component Monthly Mean Surface List of vflx.*.nc files plot
Salinity Monthly Mean Multiple List of salt.*.nc files plot
u-component of current Monthly Mean Multiple List of ucur.*.nc files plot
v-component of current Monthly Mean Multiple List of vcur.*.nc files plot
Geometric vertical velocity (dz/dt) Monthly Mean Multiple List of dzdt.*.nc files plot
Potential temperature Monthly Mean Multiple List of pottmp.*.nc files plot

Usage Restrictions:

  • None

Detailed Description:

  • A detailed description can be found here (pdf) from CPC. GODAS is a real-time ocean analysis and a reanalysis. It is used for monitoring, retrospective analysis as well as for providing oceanic initial conditions for the CFS. Both temperature and synthetic salinity profiles are assimilated in a 3DVAR scheme designed by Derber and Rosati (1989). 40 vertical levels are in the model together with 1x1 data values (enhanced in resolution to 1/3x1/3 degrees latitude within 10 degrees of the equator). The data is provided at 1/3x1/3 degrees for all latitudes. The GODAS is forced by the momentum flux, heat flux and fresh water flux from the NCEP atmospheric Reanalysis 2. It appears to reproduce observations quite well (see the references).

Caveats:

  • None

Related File Naming & Structure Information:

File Names:

  • var.yyyy.nc   (In directory: /Datasets/godas)

OpenDap File Names:

  • http://www.esrl.noaa.gov/psd/thredds/dodsC/Datasets/godas/var.yyyy.nc   

Dataset Format and Size:

  • PSD standard NetCDF 3.6 Mbyte file for each yearly single layer monthly mean file (packed).
  • PSD standard NetCDF ~144 Mbyte file for each yearly multi-level monthly mean file (packed).

Missing Data:

  • Missing data is flagged with a value of 32767s.

Citation:

  • Please note: If you acquire GODAS data products from PSD, we ask that you acknowledge us in your use of the data. This may be done by including text such as GODAS data provided by the NOAA/OAR/ESRL PSD, Boulder, Colorado, USA, from their Web site at http://www.esrl.noaa.gov/psd/ in any documents or publications using these data. We would also appreciate receiving a copy of the relevant publications. This will help PSD to justify keeping the GODAS data set freely available online in the future. Thank you!

References:

  • References Behringer, D.W., M. Ji, and A. Leetmaa, 1998: An improved coupled model for ENSO prediction and implications for ocean initialization. Part I: The ocean data assimilation system. Mon. Wea. Rev., 126, 1013-1021.
  • Behringer, D.W., and Y. Xue, 2004: Evaluation of the global ocean data assimilation system at NCEP: The Pacific Ocean. Eighth Symposium on Integrated Observing and Assimilation Systems for Atmosphere, Oceans, and Land Surface, AMS 84th Annual Meeting, Washington State Convention and Trade Center, Seattle, Washington, 11-15. Derber, J.C., and A. Rosati, 1989: A global oceanic data assimilation system. J. Phys. Oceanogr., 19, 1333-1347.
  • Ji, M., A. Leetmaa, and J. Derber, 1995: An ocean analysis system for seasonal to interannual climate studies. Mon. Wea. Rev., 123, 460-481. S. Saha, S. Nadiga, C. Thiaw, J. Wang, W. Wang, Q. Zhang, H. M. van den Dool, H.-L. Pan, S. Moorthi, D. Behringer, D. Stokes, M. Peľa, S. Lord, G. White, W. Ebisuzaki, P. Peng, P. Xie , 2006 : The NCEP Climate Forecast System. Accepted J. Climate.

Original Source:

Contact:

  • Physical Sciences Division: Data Management
    NOAA/ESRL/PSD
    325 Broadway
    Boulder, CO 80305-3328
    esrl.psd.data@noaa.gov