232 Lennart Funkquist and Rans Dahlin
can, from the view-point oftransportation, be regarded as islands and for these Baltic countries in particular, but also for the others, shipping all the year around is of
major importance for their export and import.
This paper focuses on three areas of operational oceanographic forecasting put
into practice on the Baltic Sea. They are
- Ice,
- Circulation including currents, sea-Ievel, temperature and salinity and
- Surface waves
They will all be explained in the following parts of this chapter.
12.2 Presently used forecasting models at SMHI
With the inclus ion of more operational models which are more or less dependent
on each other and even two-way coupled, the requirement of a robust and secure
operational system has increased dramatically. Once starting from one operational
atmospheric model, the operational environment now includes a whole range of
forecast models and routines for handling observational data covering all three
major disciplines at SMHI, Swedish Meteorological and Hydrological Institute
(meteorology, oceanography and hydrology). The possibility that e.g. observations
don't get into the assimilation process in time or that computer problems prevent
the forecast model to be run, has to be taken care of. This is usually done by prescribing a deadline or in the latler case by giving access to forecast fields produced
by other countries. As the computer capacity is often used at maximum, restrictions
to the possibiIity of rerunning single forecast modules exist. This, together with the
fact that the distribution of forecast products are also associated with deadlines,
makes the whole system very sensitive to any disturbance. A simplified picture of
SMHI's operational system as related to oceanography is depicted in Fig. 12.1.
The model system for operational oceanography is built up ofthree different and
more or less coupled modules. The basic component is HIROMB (Funkquist and
Kleine, 2000), a 3-dimensional baroclinic circulation model including a fully thermodynamic coupling with the atmosphere. Wind generated waves are calculated
with a nested version of a second generation wave model (HYPAS, Giinther et
al.,1983, 1984). Although a complete ice model is included in HIROMB, BOBA, a
uniquely designed ice model for the Baltic Sea, is used for forecasts of ice (Omstedt et al, 1994, 1995). All oceanographic models are forced by forecast fields from
the HIRLAM atmospheric model with a resolution of 22 and 44 lan. At present,
HIROMB is running on a Cray T3E, while the HYPAS and BOBA models are running on local operational workstations.
can, from the view-point oftransportation, be regarded as islands and for these Baltic countries in particular, but also for the others, shipping all the year around is of
major importance for their export and import.
This paper focuses on three areas of operational oceanographic forecasting put
into practice on the Baltic Sea. They are
- Ice,
- Circulation including currents, sea-Ievel, temperature and salinity and
- Surface waves
They will all be explained in the following parts of this chapter.
12.2 Presently used forecasting models at SMHI
With the inclus ion of more operational models which are more or less dependent
on each other and even two-way coupled, the requirement of a robust and secure
operational system has increased dramatically. Once starting from one operational
atmospheric model, the operational environment now includes a whole range of
forecast models and routines for handling observational data covering all three
major disciplines at SMHI, Swedish Meteorological and Hydrological Institute
(meteorology, oceanography and hydrology). The possibility that e.g. observations
don't get into the assimilation process in time or that computer problems prevent
the forecast model to be run, has to be taken care of. This is usually done by prescribing a deadline or in the latler case by giving access to forecast fields produced
by other countries. As the computer capacity is often used at maximum, restrictions
to the possibiIity of rerunning single forecast modules exist. This, together with the
fact that the distribution of forecast products are also associated with deadlines,
makes the whole system very sensitive to any disturbance. A simplified picture of
SMHI's operational system as related to oceanography is depicted in Fig. 12.1.
The model system for operational oceanography is built up ofthree different and
more or less coupled modules. The basic component is HIROMB (Funkquist and
Kleine, 2000), a 3-dimensional baroclinic circulation model including a fully thermodynamic coupling with the atmosphere. Wind generated waves are calculated
with a nested version of a second generation wave model (HYPAS, Giinther et
al.,1983, 1984). Although a complete ice model is included in HIROMB, BOBA, a
uniquely designed ice model for the Baltic Sea, is used for forecasts of ice (Omstedt et al, 1994, 1995). All oceanographic models are forced by forecast fields from
the HIRLAM atmospheric model with a resolution of 22 and 44 lan. At present,
HIROMB is running on a Cray T3E, while the HYPAS and BOBA models are running on local operational workstations.