Home Datasets GLBv0.08 expt_93.0
GOFS 3.1: 41-layer HYCOM + NCODA Global 1/12° Analysis Print
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Title: Global Ocean Forecasting System (GOFS) 3.1 output on the GLBy0.08 grid
Resolutions: GLBy0.08 grid is 0.08 deg lon x 0.04 deg lat that covers 80S to 90N.

** GLBv0.08 Discontinued on 2020-Feb-18 ** grid is 0.08 deg lon x 0.08 deg lat between 40S-40N. Poleward of 40S/40N, the grid is 0.08 deg lon x 0.04 deg lat. It spans 80S to 90N.
Institution: Naval Research Laboratory: Ocean Dynamics and Prediction Branch
Date/Data Range: 2014-July to Present [missing data]
Experiment Sequence: 56.3 -> 57.2 -> 92.8 -> 57.7 -> 92.9 -> 93.0
Temporal Frequency: 3 hourly ("standard" fields & "ice" fields)
1 hourly ("sur" diagnostic fields)
Data Formats: NetCDF (THREDDS):
  • "standard" variables
  • "ice" sea ice fields
  • "sur" surface/diagnostic fields

  • native HYCOM .[ab] (HTTP/HTTPS/FTP):
  • archm (daily mean fields)
  • archv (instantaneous fields)
  • meanstd (monthly/yearly mean fields)

  • What are the major differences between GOFS 3.1 & GOFS 3.0?

    System Description

    This dataset is created at NRL and provided "as is".

    Surface forcing is from NAVGEM.

    How It's Generated:

    1. NRL interpolates the archive files from GLBb0.08 to GLBy0.08 (GLBv0.08 Discontinued on 2020-Feb-18), using isubaregion. Note that this now reads in a “gmap” file that defines the mapping between the two grids. Therefore, isubaregion only does the interpolation (isuba_gmapi, only run once, calculates the actual bilinear remapping weights).
    2. Next, NRL runs archv2ncdf3z on the resulting file using the “NAVO” (NetCDF) output type (interpolated to 40 standard levels). Only five fields are provided: SSH, zonal velocity, meridional velocity, temperature, and salinity. Note: NRL writes out in-situ temperature, not potential temperature. This format also uses short_ints to store fields (which saves space).

    Data Assimilation

    The system uses the Navy Coupled Ocean Data Assimilation (NCODA) system (Cummings, 2005; Cummings and Smedstad, 2013) for data assimilation. NCODA uses the 24-hour model forecast as a first guess in a 3D variational scheme and assimilates available satellite altimeter observations, satellite, and in-situ sea surface temperature as well as in-situ vertical temperature and salinity profiles from XBTs, Argo floats and moored buoys. Surface information is projected downward into the water column using Improved Synthetic Ocean Profiles (Helber et al., 2013).

    Operational Details

    The system runs daily at the Navy DoD Supercomputing Resource Center and generates a nowcast out through a seven-day forecast. The output is made available typically within two days after the model run via servers located at the Center for Ocean-Atmosphere Predictions Studies (COAPS), Florida State University (FSU).

    Detailed Information

    Run configuration (blkdat.input): contains model run configuration information such as time steps, advection scheme, mixed layer submodel, vertical structure, etc.

    Model bathymetry (depth_GLBb0.08_??.[ab]): Files containing the model bathymetry on the native grid.

    Computational grid (regional.grid.[ab]): Files containing the location of the model grid points.

    "Standard" Fields/Variables :
    (2d) salinity_bottom = Salinity
    (2d) surf_el = Water Surface Elevation
    (2d) water_temp_bottom = Water Temperature
    (2d) water_u_bottom = Eastward Water Velocity
    (2d) water_v_bottom = Northward Water Velocity
    with Vertical Levels ( depth ) : 0.0 2.0 4.0 6.0 8.0 10.0 12.0 15.0 20.0 25.0 30.0 35.0 40.0 45.0 50.0 60.0 70.0 80.0 90.0 100.0 125.0 150.0 200.0 250.0 300.0 350.0 400.0 500.0 600.0 700.0 800.0 900.0 1000.0 1250.0 1500.0 2000.0 2500.0 3000.0 4000.0 5000.0 m
    (3z) salinity = Salinity
    (3z) water_temp = Water Temperature
    (3z) water_u = Eastward Water Velocity
    (3z) water_v = Northward Water Velocity
    "_ice" Sea Ice Fields/Variables :
    (2d) sic = sea_ice_area_fraction
    (2d) sih = sea_ice_thickness
    (2d) siu = eastward_sea_ice_velocity
    (2d) siv = northward_sea_ice_velocity
    (2d) sss = sea_water_salinity
    (2d) sst = sea_water_temperature
    (2d) ssu = eastward_sea_water_velocity
    (2d) ssv = northward_sea_water_velocity
    (2d) surtx = surface_downward_eastward_stress
    (2d) surty = surface_downward_northward_stress
    "_sur" surface/diagnostic Fields/Variables :
    (2d) emp = surf. water flux [93.0H]
    (2d) mixed_layer_thickness = mix.layr.thickness [93.0H]
    (2d) qtot = surf. heat flux [93.0H]
    (2d) ssh = sea surf. height [93.0H]
    (2d) steric_ssh = steric SSH [93.0H]
    (2d) surface_boundary_layer_thickness = bnd.layr.thickness [93.0H]
    (2d) u_barotropic_velocity = baro. u-vel. [93.0H]
    (2d) v_barotropic_velocity = baro. v-vel. [93.0H]


    Global Ocean Forecasting System (GOFS) 3.1 website
    Contains snapshots, animations forecast verification statistics and model data comparisons.
    (Cummings, J.A., 2005)
    Cummings, J.A., 2005: Operational multivariate ocean data assimilation. Quart. J. Royal Met. Soc., Part C, 131(613), 3583-3604.
    (Cummings, J.A. and O.M. Smedstad. 2013)
    Cummings, J.A. and O.M. Smedstad. 2013: Variational Data Assimilation for the Global Ocean. Data Assimilation for Atmospheric, Oceanic and Hydrologic Applications. Vol. II, chapter 13, 303-343.
    (Helber, R.W., T.L. Townsend, C.N. Barron, J.M. Dastugue and M.R. Carnes, 2013)
    Helber, R.W., T.L. Townsend, C.N. Barron, J.M. Dastugue and M.R. Carnes, 2013: Validation Test Report for the Improved Synthetic Ocean Profile (ISOP) System, Part I: Synthetic Profile Methods and Algorithm. NRL Memo. Report, NRL/MR/7320—13-9364.



    This is a demonstration product from the HYCOM Consortium and is provided as is. HYCOM Consortium does not warrant or suggest that this data is fit for any particular purpose. Further, neither COAPS nor HYCOM consortium guarantees availability, service updates, or timely data delivery.

    All hycom data provided is UNCLASSIFIED. DoD DISTRIBUTION A. Approved for Public Release; Distribution Unlimited.