FOAM
399
The global configuration is also driven by climatological monthly river
inflow data from the Global Runoff Data Centre (GRDC) with the outflows
from the largest 20 rivers adjusted to accord with Baumgartner & Reichel
(1975).
Temperature and salinity profile data are assimilated at all depths (see
section 3.1). In the operational system the data are obtained from BATHY,
TESAC and BUOY messages distributed by the Global Telecommunications
System (GTS). These message formats are used to report expendable
bathythermograph (XBT) data reported by Voluntary Observing Ships
(VOS), and data from the Argo profiling floats and TAO/Triton equatorial
moorings respectively. Quality control checks on these data include track,
stability, background and buddy checks (Ingleby & Huddleston 2004).
Altimeter data from the Jason-1, Envisat and Geosat Follow-On (GFO)
satellites are assimilated in all but the global configuration using products
supplied twice a week by Collecte Localisation Spatiale (CLS) in Toulouse.
In situ surface temperature data from ships and drifting and moored
buoys are assimilated. At present only advanced high resolution radiometer
(AVHRR) data on a coarse grid (2.5
o spacing) are assimilated. All these data
are distributed by the Global Telecommunications System (GTS). We will
upgrade to using GODAE High Resolution SST (GHRSST) satellite data
products when they become available.
Sea-ice concentration fields supplied by the Canadian Met Centre
(CMC) on a daily basis are also assimilated. These fields are based on
SSM/I (special sensor microwave imager) data processed using the
York/AES algorithm (Ramseier et al. 1988).
2.3
Dynamical model
Storkey (2004) provides an excellent summary of the formulation of the
physical ocean and sea-ice models used by FOAM in July 2004. The ocean
model code, which originated from the Bryan-Cox code (Bryan 1969, Cox
1984), is developed jointly with groups in the Hadley Centre who use it for
climate prediction. The FOAM formulation is quite close to that used by
HadCM3 (Gordon et al. 2000).
Various bathymetries (Smith & Sandwell 1997, DBDB2 and GEBCO)
have been used in building the present configurations. The bathymetry after
interpolation to the model’s grid is smoothed twice using a 1-4-1 filter. Gridscale holes are filled to avoid an instability (Pacanowski & Griffies 1999)
which appears to be associated witih the B-grid staggering of variables and
the depth and width of important channels are adjusted using Thompson
(1996) as a reference. At open boundaries of nested models the bathymetry
in the relaxation zone (see below) is reset to be as similar as possible to the
model providing its boundary data. Tests of the impact of code to achieve a
399
The global configuration is also driven by climatological monthly river
inflow data from the Global Runoff Data Centre (GRDC) with the outflows
from the largest 20 rivers adjusted to accord with Baumgartner & Reichel
(1975).
Temperature and salinity profile data are assimilated at all depths (see
section 3.1). In the operational system the data are obtained from BATHY,
TESAC and BUOY messages distributed by the Global Telecommunications
System (GTS). These message formats are used to report expendable
bathythermograph (XBT) data reported by Voluntary Observing Ships
(VOS), and data from the Argo profiling floats and TAO/Triton equatorial
moorings respectively. Quality control checks on these data include track,
stability, background and buddy checks (Ingleby & Huddleston 2004).
Altimeter data from the Jason-1, Envisat and Geosat Follow-On (GFO)
satellites are assimilated in all but the global configuration using products
supplied twice a week by Collecte Localisation Spatiale (CLS) in Toulouse.
In situ surface temperature data from ships and drifting and moored
buoys are assimilated. At present only advanced high resolution radiometer
(AVHRR) data on a coarse grid (2.5
o spacing) are assimilated. All these data
are distributed by the Global Telecommunications System (GTS). We will
upgrade to using GODAE High Resolution SST (GHRSST) satellite data
products when they become available.
Sea-ice concentration fields supplied by the Canadian Met Centre
(CMC) on a daily basis are also assimilated. These fields are based on
SSM/I (special sensor microwave imager) data processed using the
York/AES algorithm (Ramseier et al. 1988).
2.3
Dynamical model
Storkey (2004) provides an excellent summary of the formulation of the
physical ocean and sea-ice models used by FOAM in July 2004. The ocean
model code, which originated from the Bryan-Cox code (Bryan 1969, Cox
1984), is developed jointly with groups in the Hadley Centre who use it for
climate prediction. The FOAM formulation is quite close to that used by
HadCM3 (Gordon et al. 2000).
Various bathymetries (Smith & Sandwell 1997, DBDB2 and GEBCO)
have been used in building the present configurations. The bathymetry after
interpolation to the model’s grid is smoothed twice using a 1-4-1 filter. Gridscale holes are filled to avoid an instability (Pacanowski & Griffies 1999)
which appears to be associated witih the B-grid staggering of variables and
the depth and width of important channels are adjusted using Thompson
(1996) as a reference. At open boundaries of nested models the bathymetry
in the relaxation zone (see below) is reset to be as similar as possible to the
model providing its boundary data. Tests of the impact of code to achieve a