Bathymetry of four deep Baltic basins
Abstract
Extensive hydrographic field campaigns were carried out by the Institute for Baltic Sea Research Warnemuende (IOW) in four deep basins of the Baltic Sea during different seasons from 1996 to 1999. The spreading and transformation of dense deep water was studied using a fixed eddy-resolving station grid within the framework of the German-Russian project MESODYN (meso scale dynamics). The station spacing of each survey was 2.5 nm, which corresponds to a station distance of 2.5' meridionally and about 4.5' zonally. Using the Global Positioning System (GPS) for navigation, statistical uncertainties of the mean ship position during station work are on the order of ± 37 m in each direction. In this way, shipborne echosounders provided representative topographic data sets for the deepest parts of the Arkona Basin, the Bornholm Basin, the Stolpe Furrow and the Eastern Gotland Basin. The absolute accuracy of water depths lies in the range of ± 1 m while its spatially determined mean standard deviation does not exceed ± 0.2 m in each survey. The resulting topographic maps are presented. Derived direction tendencies of deep circulation patterns result from conservation of their potential vorticity above topographic irregularities. Resulting vectors suggest a permanent tendency for cyclonic circulation within all four deep Baltic basins. The most intense topographic control of the deep circulation must be expected above both the eastern and western flanks of the Eastern Gotland Basin. Beneath closed bathymetric contours, depthareavolume relationships have been estimated numerically to characterise the storage capacity of each basin for dense deep water.
- Publication:
-
Deutsche Hydrographische Zeitschrift
- Pub Date:
- December 1999
- DOI:
- 10.1007/BF02764169
- Bibcode:
- 1999DeHyZ..51..489R
- Keywords:
-
- Global Position System;
- Potential Vorticity;
- Deep Basin;
- Differential Global Position System;
- German Journal