MEPS 156:255-261 (1997)  -  doi:10.3354/meps156255

Hydrographic observations and model results from a PRISMA drift experiment

Peter König1,*, Corinna Schrum2

1Bundesamt für Seeschiffahrt und Hydrographie, Bernhard-Nocht-Str. 78, D-20359 Hamburg, Germany
2Zentrum für Meeres- und Klimaforschung der Universität Hamburg, Institut für Meereskunde, Troplowitzstr. 7, D-22529 Hamburg, Germany

A drift experiment was conducted from 23 to 29 April 1991 in the central western part of the German Bight as part of the German research program PRISMA. Observed hydrographic time series and results from a numerical model are presented. The discussion focuses on the problem of whether the drift buoy used was suitable for marking a 'selected water body' in order to study specific processes. Based upon the data and the model outcome, the experiment had to be divided into 2 phases. During the first phase the drift buoy was situated in denser water with relatively low concentrations of suspended particulate matter (SPM)and phytoplankton. On 26-27 April, a storm event initiated the second phase. The buoy was then forced to deviate from its expected position into a water mass of a more coastal type characterized by slightly higher temperatures, lower salinity and lower transmission. Concentrations of phytoplankton and SPM increased. The passage of a weak salinity front between 2 stations on 29 April was identified in the data as well as in the simulated salinity distribution.

German Bight · Drift experiment · Drogue · Numerical model · Hydrography

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