We work with process oriented modelling and develop time-dependent
coupled-basin models in close relation to validation and analyses
of forcing data. An introduction to process-oriented lake and ocean
modelling is given in Omstedt (2004). For the Baltic Sea we use the
PROBE-Baltic model. The model uses the PROBE program for solving
a number of equations. The building of PROBE-Baltic started in the
early 1980’s. The first problem considered was
cooling of the ocean surface layer around the temperature of maximum
density and forecasting sea surface cooling. A four coupled basin model
for the Baltic Sea entrance area were then formulated to analyses the
effects of advection on the surface heat balance. In 1990, the first
version of PROBE-Baltic was published, where the Baltic Sea was divided
into 13 sub-basins and applied as a forecasting model. At this stage
sea ice was not included but a new ice model for coastal seas was developed.
Sea ice processes were then studied and in 1996 a coupled ice-ocean
version of PROBE-Baltic was published and the climate sensitivity of
the Baltic Sea was examined. The deep-water circulation and salinity
as well as temperature variations were later examined. The PROBE-Baltic
model has also been applied in a number of other works related to climate,
water and heat balances studies. A full description of the mathematical
modelling, covering forcing as well as validation data, appears in
Omstedt and Axell (2003).
(Click image to enlarge)
Figure 1. A sketch of some important processes
to be considered in Baltic Sea modelling. From Winsor et al. (2001,
- Omstedt,A. (2004). Introduction to Lake and Ocean modelling. Compendium
available from the author.
- Omstedt, A. and L., Axell (2003). Modeling the variations of salinity
and temperature in the large Gulfs of the Baltic Sea. Continental
Shelf Research, 23, 265-294.
- Winsor, P., J. Rodhe, and A. Omstedt (2003). Erratum: Baltic Sea
ocean climate: an analysis of 100 yr of hydrographic data with focus
on the freshwater budget, Climate Research, 25, 183.
- Winsor, P., J. Rodhe, and A. Omstedt (2001). Baltic Sea ocean climate:
an analysis of 100 yr of hydrographic data with focus on the freshwater
budget, Clim. Res., 18, 5-15.
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