North Atlantic Ocean Prediction System |
| System Description |
| The system is configured for the North and Equatorial Atlantic region and uses HYCOM 2.1 as the dynamical model. The computational domain extends from 98oW to 36.5o E and 28oS to 70oN and the computations are carried out on a mercator grid with 1/12o (1678 x 1609 grid points, 6.5 km spacing on average) resolution. There are 26 vertical layers (see blkdat.input). Bathymetry is derived from a quality controled ETOPO 2.5 dataset. Surface forcing is from Navy Operational Global Atmospheric Prediction System (NOGAPS) and includes wind stress, wind speed, heat flux (using bulk formula), precipitation. The model is outfitted with a 3o buffer zone in the north and south boundaries where temperature and salinity is relaxed to monthly climatological T and S from Modular Ocean Data Assimilation System (MODAS). For details on the advection scheme, mixing etc. see blkdat.input. |
| Data Assimilation |
| The system assimilates operational MODAS sea surface elevation analysis of daily available satellite altimeter observations. The assimilation scheme uses a mean sea surface elevation data from a 5 year run of MICOM forced by ECMWF daily winds. The altimeter signal is projected vertically using the Cooper-Haines technique (JGR; 1996). Sea Surface Temperature (SST) is relaxed to the daily MODAS SST analysis. |
| Operational details and data availablity |
| The system runs on wednesday every week and produces a 10 day hindcast and a 14 day forecast. The data are made available typically within a day from servers located at Center For Ocean Atmospheric Prediction Studies (COAPS), Florida State University(FSU). The HYCOM format archive files are converted to CF 1.0 compliant NetCDF files using standard HYCOM post-processing package. These files contain diagnostic output at standard Levitus depth levels for several variables including currents, temperature and salinity. These files can be accessed using any OPeDAP enabled client e.g, ferret, NCO etc. The OPeNDAP URL's are listed below and can be looked up from the HYCOM THREDDS Catalog. The Live Access Server allows request for a number of products such as images, custom subsets of data, data access scripts etc. Individual files can also be accessed via standard anonymous FTP. |
| Information on Run Configuration, Computational Grids, Model Bathymetry and Variables |
| blkdat.input Contains model run configuration information such as time steps, advection scheme, mixing etc, vertical structure etc. |
| regional.grid Files containing the location of model grid points |
| regional.depth Files containing the model bathymetry |
| OPeNDAP.info List of model variables and metadata |
| Reference: NRL Website contains snapshots, animations forecast verification statistics and model data comparisons. |
| Disclaimer: 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, COAPS does not guarantee availability, service updates or timely data delivery |
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