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| Titel |
Spatial and temporal variability of R1 in the Bay of Koper (Gulf of Trieste) |
| VerfasserIn |
R. Soczka Mandac, B. Bogunović |
| Konferenz |
EGU General Assembly 2012
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 14 (2012) |
| Datensatznummer |
250065627
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| Zusammenfassung |
| The space and time distribution of the internal Rossby radius of deformation (R1) is explored
for the Bay of Koper (Bay). The main objective of this study is evaluation of the seasonal
thermohaline variation in the Bay on meso-scale processes. While currents along
the southern coastline of the Gulf of Trieste are known [1]; the shape of density
isolines in the vertical plane of a coastal belt of fresher water in the Bay are not
known.
The calculation of R1 follows the method of vertical modes (the eigenvalue problem),
calculated from vertical profiles of buoyancy frequency. R1 was obtained from numerous
field measurements of temperature and salinity (CTD) in 2011. CTD casts were
collected forth nightly on a regular 35 sampling points in May and December 2011.
Obtained data were processed and spatial interpolated with an Objective Analysis
method.
Space distribution of R1, calculated from the first vertical mode of seasonal temperature and
salinity, reveals that during seasons with a stratified sea (spring-autumn) R1 increases in an
offshore direction. The largest R1 (15 km) was observed in the port basin at the beginning of
June and the smallest R1 (1 km) in the southern part of the Bay. During early autumn the
maximum R1 (8 km) was observed in the offshore direction (west), while minimum R1 (1
km) near the southern coastline of the Bay. In the winter season, the maximum R1(6 km) was
noticed again in offshore direction, while the minimum value (500 m) was in the southern
part of the Bay. This seems surprising, since the lowest values are attributed to regions of the
highest stratification Badaševica river. However, in linear vertical stratification R1 is
proportional to the product of buoyancy frequency and the depth distribution drastically
varies in relation to the fresh water inflow (Badaševica river) while in the winter
season the R1 distribution pattern is related to the bathymetric shape of the bay [2].
Similar distributions of R1 were found in the Baltic Sea and the Bay of Finland
[3].
References:
1. Bogunović B. and MalaÄiÄ V., 2008. Circulation in the Gulf of Trieste: Measurements and
model results. Nuovo Cimento (C), 31, C3, 301-326.
2. Fennel W., Seifert T. and Kayser B., 1991. Rossby radii and phase speeds in the Baltic Sea.
Cont. Shelf Res., 11: 23-36.
3. Pekka A., Nekrasov A. and Myberg K., 2003. Variability of the baroclinic Rossby radius in
the Gulf of Finland. Cont. Shelf Res., 23: 563-573. |
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