Beschreibung:
<jats:p>Abstract. Baltic Sea bathymetric properties are analysed here using the newly released
digital bathymetric model (DBM) by the European Marine Observation and Data
Network (EMODnet). The analyses include hypsometry, volume, descriptive
depth statistics, and kilometre-scale seafloor ruggedness, i.e. terrain
heterogeneity, for the Baltic Sea as a whole as well as for 17 sub-basins
defined by the Baltic Marine Environment Protection Commission (HELCOM). We
compare the new EMODnet DBM with IOWTOPO the previously most widely used
DBM of the Baltic Se aproduced by the Leibniz-Institut für Ostseeforschung Warnemünde (IOW), which has served as the primary gridded bathymetric
resource in physical and environmental studies for nearly two decades. The
area of deep water exchange between the Bothnian Sea and the Northern Baltic
Proper across the Åland Sea is specifically analysed in terms of depths
and locations of critical bathymetric sills. The EMODnet DBM provides a
bathymetric sill depth of 88 m at the northern side of the Åland Sea and
60 m at the southern side, differing from previously identified sill depths
of 100 and 70 m, respectively. High-resolution multibeam bathymetry acquired
from this deep water exchange path, where vigorous bottom currents
interacted with the seafloor, allows us to assess what presently available
DBMs are missing in terms of physical characterization of the seafloor. Our
study highlights the need for continued work towards complete
high-resolution mapping of the Baltic Sea seafloor.
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