This site contains real-time and archived nowcast/forecast results from the 1/32° global Naval Research Laboratory (NRL) Layered Ocean Model (NLOM), including snapshots, animations and forecast verification statistics for many zoom regions, mainly sea surface height (SSH), sea surface temperature (SST) and surface currents. It also contains direct model-data comparisons. In addition, this site contains the real-time and archive results from the 1/8° global NCOM nowcast/forecast system from the global Modular Ocean Data Assimilation (MODAS) 1/4° SSH and 1/8° SST analyses, again with snapshots and animations for many zoom regions. The MODAS web pages also contain a direct look at the real-time altimeter data available and comparisons between the operational NLOM and MODAS SSH and SST analyses. The SSH and SST anomalies are analysis deviations from climatology.
The 1/32° global NLOM is an operational product run daily by the Naval Oceanographic Office (NAVOCEANO) with atmospheric forcing from the Navy Operational Global Atmospheric Prediction System (NOGAPS) and assimilation of SST and satellite altimeter data the latter obtained via the NAVOCEANO Altimeter Data Fusion Center.
The NLOM assimilation of altimeter data is performed using an OI deviation SSH analysis with the model SSH field as the first guess. A statistical inference technique updates all layers of the model based on the analyzed SSH deviations and a geostrophic update for the velocity field is calculated outside the equatorial region. An incremental updating scheme is used to assimilate the data. Currently, GEOSAT Follow-On (GFO), JASON1 and ENVISAT data are being assimilated. The MODAS SST analyses of satellite IR data are also assimilated. During the 30-day forecasts the atmospheric forcing gradually reverts to climatology and SST is relaxed toward climatologically corrected persistence with an e-folding time scale of 1/4 the elapsed forecast length.
The 1/32° global NLOM web page is updated daily by NRL and the web page should be considered a demonstration product. The 1/16° global NLOM was discontinued 12 Mar 2006, but archived results are still available below.
MODAS is an optimum interpolation (OI) analysis using the previous analysis as the first guess and is currently running at 1/8° globally for SST and 1/4° for SSH. It currently runs daily and fli animations are available for the last 30 days, last 12 months, and all daily data from 1993.
NRL and NAVOCEANO are participants in the multi-national Global Ocean Data Assimilation Experiment (GODAE) including presence on the U. S. and international steering teams. GODAE is aimed at demonstrating real-time global ocean products in a way that will promote wide utility and availability for maximum benefit to the community.
For 1/8° Global NCOM data click here
For .08° Global HYCOM data click here NEW!
For information about the HYbrid Coordinate Ocean Model (HYCOM) click here NEW!
For animations of 1/8° Global MODAS2D data click here
For 1/16° Global NLOM data click
here Discontinued 12 Mar 2006. Archived results are still available. Replaced by 1/32° global NLOM.
Disclaimer:Although 1/32° global NLOM and the MODAS SSH and SST analyses are operational products of NAVOCEANO, this web page is a product of NRL research and development and is experimental in nature. NRL is providing the INFORMATION on an "as is" basis. NRL does not warrant or represent this INFORMATION is fit for any particular purpose, and NRL does not guarantee availability, service, or timely delivery of data.
This is an official U.S. Navy web site .
Links:
Naval Research Laboratory
U. S. Navy
Navy FOIA
Office of Naval Research