Fixed Vertical Coordinates• POM• SWAFS• POP• NCOM

Lagrangian Vertical Coordinate

• NLOM

Hybrid Vertical Coordinate

• HYCOM

Lagrangian Vertical Coordinate

SWAFSShallow Water Analysis and Forecast System

Primary contacts: Charlie Horton (NAVO)

SWAFS was developed in house at NAVO. “SWAFS is an ocean forecasting system which has undergone continual development and expanding use since 1990 when a version of POM was applied to the Persian Gulf.” (Horton and Clifford, 2001)

“A version of POM driven by near-real-time meteorological fields remains at the core of SWAFS, but the system today includes a data assimilation scheme using connections to data bases for in situ observations, ocean surface temperature measurements from satellites, and synthetic temperature/salinity profiles inferred from altimetry” (Horton and Clifford, 2001). It includes vertically and horizontally varying temperature and salinity, and has wind, thermohaline, and tidal forcing.

SWAFSNo informational web site

Domain• There are provisions for one-way nesting of smaller,

higher resolution domains within larger, coarser resolution domains.

• In April 2001, there were 5 host domains: Red Sea, Baltic Sea, Mediterranean Sea, North Pacific, and North World.

• 10 other domains were nested within these, including Adriatic Sea and Arabian Sea

• As of July 2002, there are NAVO products for 24 regions, but it is hard to tell which are host domains, which are nested domains, and which are regions cut out from a host or nested domain for display purposes.

Spatial Resolution• Rectilinear grid with uniform spacing over the domain is

used.• Largest domains (North World and North Pacific) use 0.27 x

0.21.• Other host domains vary from 10 km (Mediterranean) to 5

km (Baltic)• Nested domains vary from ~ 1 to 10 km resolution.• Red Sea, for example, uses 7 km resolution along the axis of

the Sea, and 6 km across (Clifford et al. 1997)• In many cases, the horizontal spatial resolution is listed in the

pop-up Product Info.• Number of levels varies by domain from 15 to 24. • Red Sea uses 22 levels, more closely spaced near the surface.

Location: Central MedType: SWAFSDescription: Albania 00-48 hrs fcst Surface Current Series (U) POC: NAVO - SWAFS Library Custodian COMM: 228-688-5176 DSN: 828-5176 or E-mail Us Update Cycle: 24 hour(s) Typical File Size: 26(K) Level-of-Confidence: This product has been validated and is recommended for support unless otherwise stated.

Current File Statistics: i.0000albhrb32000.gif Size: 41 (Kbytes) Last Update: 19-Jul-15:06 CDT (U)

ii.0300albhrb32000.gif Size: 40 (Kbytes) Last Update: 19-Jul-15:06 CDT (U) iii.0600albhrb32000.gif Size: 41 (Kbytes) Last Update: 19-Jul-15:06 CDT (U) iv.0900albhrb32000.gif Size: 42 (Kbytes) Last Update: 19-Jul-15:06 CDT (U) v.1200albhrb32000.gif Size: 42 (Kbytes) Last Update: 19-Jul-15:06 CDT (U) vi.1500albhrb32000.gif Size: 43 (Kbytes) Last Update: 19-Jul-15:06 CDT (U) vii.1800albhrb32000.gif Size: 43 (Kbytes) Last Update: 19-Jul-15:06 CDT (U) viii.2100albhrb32000.gif Size: 42 (Kbytes) Last Update: 19-Jul-15:06 CDT (U) ix.2400albhrb32000.gif Size: 42 (Kbytes) Last Update: 19-Jul-15:06 CDT (U) x.2700albhrb32000.gif Size: 42 (Kbytes) Last Update: 19-Jul-15:06 CDT (U) xi.3000albhrb32000.gif Size: 41 (Kbytes) Last Update: 19-Jul-15:06 CDT (U) xii.3300albhrb32000.gif Size: 42 (Kbytes) Last Update: 19-Jul-15:06 CDT (U) xiii.3600albhrb32000.gif Size: 44 (Kbytes) Last Update: 19-Jul-15:06 CDT (U) xiv.3900albhrb32000.gif Size: 42 (Kbytes) Last Update: 19-Jul-15:06 CDT (U) xv.4200albhrb32000.gif Size: 41 (Kbytes) Last Update: 19-Jul-15:06 CDT (U) xvi.4500albhrb32000.gif Size: 42 (Kbytes) Last Update: 19-Jul-15:06 CDT (U) xvii.4800albhrb32000.gif Size: 42 (Kbytes) Last Update: 19-Jul-15:06 CDT (U)

Additional Information: i.Initial Posting on Tue Jul 3 11:05:27 2001 (CST) (U) ii.Numerical model resolution is 3.3 x 2.5 km. All vectors are plotted. (U)

Boundary Conditions• Initially run in enclosed, or nearly enclosed, basins,

although current domains include more open areas.• Radiation condition for V and outflow T and S at

open boundaries for most domains. • Climatological or data assimilation may be used to

specify T and S of inflow at open boundaries.• At the Strait at Bab al Mandab at the south end of the

Red Sea, time-varying thermohaline- and wind-driven inflow/outflow are allowed, but long-term draining or filling of the basin is prevented. (Clifford et al. 1997)

• Velocity profiles at Gibraltar and Dardenelles straits are specified and held constant for Mediterranean. (Horton et al. 1997)

Bathymetry

• DBDB1, DBDB2, DBDB5, DBDBV, or a mixture of these, depending on domain

• In some cases, as in Red Sea, bathymetry has been smoothed to limit pressure gradient errors from steep bottom slopes. (Clifford et al. 1997)

Forcing• Climatological rainfall and river input• Large domains use NOGAPS winds and

heat flux • Small domains use

– Wind stress from COAMPSTM

– Surface heat flux computed within SWAFS– Evaporation based on COAMPSTM and MC-

SST

• Red Sea uses Littoral Atmospheric Boundary Layer Model (part of SWAFS) for winds and heat flux

The information presented in this slide could not be confirmed.

Tidal Forcing

• At open boundaries:– Tidal heights specified from published co-tidal

charts (used for Arabian Gulf, Red Sea, and Mediterranean Sea).

– Tidal heights and currents from a host domain.• Astronomical tide generating forces applied as a

body force. Included only for large domains.• Tidal elevations from Kantha’s (Univ. of

Colorado) global tidal model nudged in over the domain.

(http://www.ssc.erc.msstate.edu/Tides2D)

Initialization

• No information available, appears to havebeen run continuously in some domains (Red Sea, Persian Gulf, Mediterranean Sea, Baltic Sea) for many years.

Data Assimilation• Remotely sensed SST• In situ T and S profile data is assimilated on

15 constant depth surfaces, the deepest of which is 600 m

• MODAS synthetic profiles assimilated along altimeter tracks only

• PALACE floats• Data are assimilated at daily intervals.• Data are optimally interpolated to the grid

and then “nudged” in over a 3 hr period. (Horton et al. 1994)

Implementation

• “Under the fault-tolerant control of a sequence of 10 scripts making the dissemination of products extremely automated. More recently the modeling system has been ported to massively scalable computers using the message passing interface (MPI).” (Horton and Clifford 2001)

• Run at MSRC. Different domains run on different computers.

Output

• Forecasts are generally done for 48 hrs.

• Model velocity fields are output in graphical format at 3-12 hr intervals, depending on the domain.

• Surface currents are displayed for all domains, subsurface currents at various depth levels are displayed for some domains.

• .cur files for input for GNOME – presently only available for the Arabian Gulf

• Example from run in Mediterranean (with exchange through Straits of Gibraltar and the Dardanelles prescribed) with 10 km spatial resolution.

• Updates once per day.

• 27 km COAMPSTM winds, surface heat flux, and tidal forcing.

SWAFS

SWAFS

Baltic Sea

Numerical model resolution is 5 km. Every 6th vector is plotted.

Location: Central MedType: SWAFSDescription: Albania 00-48 hrs fcst Surface Current Series (U) POC: NAVO - SWAFS Library Custodian COMM: 228-688-5176 DSN: 828-5176 or E-mail Us Update Cycle: 24 hour(s) Typical File Size: 26(K) Level-of-Confidence: This product has been validated and is recommended for support unless otherwise stated. Current File Statistics: i.0000albhrb32000.gif Size: 41 (Kbytes) Last Update: 19-Jul-15:06 CDT (U)

etc.

Additional Information: i.Initial Posting on Tue Jul 3 11:05:27 2001 (CST) (U) ii.Numerical model resolution is 3.3 x 2.5 km. All vectors are plotted. (U)

Location: Adriatic SeaType: SWAFSDescription: Slovenia 00-48 hrs fcst Bottom Currents Series (U) POC: NAVO - SWAFS Library Custodian COMM: 228-688-5176 DSN: 828-5176 or E-mail Us Update Cycle: 24 hour(s) Typical File Size: 50(K) Level-of-Confidence: This product has been validated and is recommended for support unless otherwise stated. Current File Statistics: i.0000slovb32999.gif Size: 25 (Kbytes) Last Update: 19-Jul-15:06 CDT (U)

Additional Information: i.Initial Posting on Thu Jul 19 17:45:42 2001 (CST) (U) ii.All model vectors are plotted. (U)

Location: Adriatic SeaType: SWAFSDescription: Adriatic Sea Tau 00-24 Surface Series (U) POC: NAVO - SWAFS Library Custodian COMM: 228-688-5176 DSN: 828-5176 or E-mail Us Update Cycle: 24 hour(s) Typical File Size: 25(K) Level-of-Confidence: This product has been validated and is recommended for support unless otherwise stated. Current File Statistics: i.0000adb32000.gif Size: 67 (Kbytes) Last Update: 19-Jul-15:06 CDT (U) etc. 

There is no additional information with this product

Persian Gulf Drift Modeling

Click anywhere in the image to view the movie of the swafs currents (quicktime file)

ReferencesHorton, C., and M. Clifford, The Shallow Water

Analysis and Forecast System (SWAFS) at the (US) Naval Oceanographic Office, in BOOS Workshop on Monitoring and Predicting Water Level and Coastal Circulation, Estonian Marine Institute, Tallinn, 2001.

Clifford, M., C. Horton, and J. Schmitz, An oceanographic nowcast/forecast system for the Red Sea, J. Geophys. Res., 102 (C11), 25101-25122, 1997.

Horton, C., M. Clifford, and J. Schmitz, A real-time oceanographic nowcast/forecast system for the Mediterranean Sea, J. Geophys. Res., 102 (C11), 25123-25156, 1997.