Barotropic wind-driven circulation patterns in a closed rectangular basin of variable depth influenced by a peninsula or an island
We study how a coastal obstruction (peninsula or coastal island) affects the <i>three-dimensional</i> barotropic currents in an oblong rectangular basin with variable bathymetry across the basin width. The transverse depth profile is asymmetric and the peninsula or island lies in the...
| Main Authors: | , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2000-06-01
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| Series: | Annales Geophysicae |
| Online Access: | https://www.ann-geophys.net/18/706/2000/angeo-18-706-2000.pdf |
| Summary: | We study how a coastal obstruction (peninsula
or coastal island) affects the <i>three-dimensional</i> barotropic currents in
an oblong rectangular basin with variable bathymetry across the basin width. The
transverse depth profile is asymmetric and the peninsula or island lies in the
middle of the long side of the rectangle. A semi-spectral model for the
Boussinesq-approximated shallow water equations, developed in Haidvogel <i>et
al.</i> and altered for semi-implicit numerical integration in time in Wang and
Hutter, is used to find the steady barotropic state circulation pattern to
external winds. The structural (qualitative) rearrangements and quanti2tative
features of the current pattern are studied under four principal wind directions
and different lengths of the peninsula and its inclination relative to the
shore. The essentially non-linear relationships of the water flux between the
two sub-basins (formed by the obstructing peninsula) and the corresponding
cross-sectional area left open are found and analysed. It is further analysed
whether the depth-integrated model, usually adopted by others, is meaningful
when applied to the water exchange problems. The flow through the channel
narrowing is quantitatively estimated and compared with the three-dimensional
results. The dynamics of the vortex structure and the identification of the
up-welling/down-welling zones around the obstruction are discussed in detail.
The influence of the transformation of the peninsula into a coastal island on
the global basin circulation is considered as are the currents in the channel.
The geometric and physical reasons for the anisotropy of the current structure
which prevail through all obtained solutions are also discussed.<br><br><b>Key words: </b>Oceanography: general (limnology; numerical
modeling) - Oceanography: physical (currents) |
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| ISSN: | 0992-7689 1432-0576 |