Analysis 03: Future Scenario—OWF Development Within German EEZ - On the Effect of Offshore Wind Farms on the Atmosphere and Ocean Dynamics - page 141

The horizontal velocity wake areas are more connected to the wind wake with
reductions in order of 0.15 m/s. The surface elevation has a dipole with a minimum
in the ocean in the area of OWFs and a maximum in coastal regions easterly of the
OWF districts of

0.1048 and 0.0449 m.
The extrema of the dipole grow with time and reach higher values than under the
theoretical conditions due to higher wind speeds.
The vertical component w at 12-m depth shows an intensification of up- and
downwelling with time. The positions of the belts correspond to the theoretical
wind direction case N with upwelling belts at the western edge of the OWF district
and downwelling at the eastern edge of the OWF district. On 19 June, the vertical
motion has values of 13.10 and 10.13 m/d. Connected with the velocity wake, the

triggered shift in temperature front, and the increase in temperature forcing, the SST
shows areas of temperature increase along the coast from west to east, which is
connected with the velocity wake, the triggered shift in temperature front, and the
increase in temperature forcing. Again, that effect dominates the field of SST, and
with the depth cooling/warming corresponds to up-/downwelling. On 19th of June,
the daily mean change of SST counts around +1.5 and 0.1 C. Depending on the

SST, the salinity concentration at surface shows a decrease of

0.18 psu on 16 June

up to 0.79 psu on 19 June and an increase of 0.77 psu. Decreases obviously occur

in the OWF districts and along the coasts southerly of OWFs from west to east
towards the Elbe estuary.
Summarizing the OWF expansion scenario B1-2030much leads to an intensified
modification of the North Sea within the area of the German Bight. Due to an
extensive vertical motion of several meters per days, triggered by wind speed and
change in surface elevation, the hydrographic conditions are strongly affected.
Special consideration to the development of the OWF effect on the ocean must
be borne in mind. Depending on the wind direction and the wind speed, ocean
conditions will easily vary within the German Bight due to OWFs with currently
unknown and unassessable effect on the ecosystem.

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