Renewable Energy Wind - On the Effect of Offshore Wind Farms on the Atmosphere and Ocean Dynamics - page 10

A summary of synoptically, hydrodynamic, and hydrographic conditions of the
overall North Sea area is given by Mathis ( 2013 ) based on Otto et al. ( 1990 ), Rodhe
( 1998 ), OSPAR ( 2000 ), and Steele et al. ( 2009 ).
Most relevant information of the North Sea for this study is its stratification of
the area within the so-called exclusive economic zone, which is defined under
Sect. 2.2.2 . The status reports of the German Federal Maritime and Hydrographic
Agency (BSH) provide information about the System North Sea. The results of that
reports show a wind statistic of mostly wind directions between southwesterly and
westerly winds for the southern part of the North Sea. On average over all seasons,
the geostrophic wind speed has been counted around 8.0 m/s since 2005. That value
is calculated at position 5 E and 55 N, which is representative of the area between
0 -10 E and 50 -60 N (Loewe 2009 ).
Sea surface temperatures count 10 C on average. Geographically, SSTs
increase from northwest to southeast. Most areas of the German EEZ are thermally
stratified in the summer with temperatures of 6-7 C at bottom and 15-18 C,
sometimes 20 C, at surface (Loewe 2009 ).
Large parts of the North Sea are water of Atlantic origin, having salinity
concentrations greater than 35. Hence, highly salty waters of Atlantic origin in
the West (35/34 psu) and low salty waters (lower than 32 psu) in the East being
influenced by Baltic sea waters and continental fresh water input, like those from
the rivers Rhine and Elbe, characterize the distribution of salinity concentration of
the North Sea.
That information is used to set up an idealized ocean having North Sea condi-
tions to analyze dynamical changes due to operating offshore wind farms.

2.2.2 Germany ' s Exclusive Economic Zone (EEZ)

States having access to oceans are able to build offshore wind farms. As a result of
UNCLOS (United Nations Convention on the Law of the Sea), states are allowed to
build such wind farms only in a special zone near their coasts. This zone is called
exclusive economic zone.

The exclusive economic zone is an area beyond and
adjacent to the territorial sea, subject to the specific legal regime established in this
part, under which the rights and jurisdiction of the coastal state and the rights and
freedoms of other states are governed by the relevant provisions of this convention,

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UNCLOS, Part V, Article 55.
Based on this definition, Germany s area for offshore wind farms in the North

Sea is restricted. The area of Germany

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s EEZ and its ocean depth are depicted in

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Fig. 2.2 . Germany s EEZ includes important shipping routes that are indefeasible.

Besides these routes, a huge area within the EEZ is useable for offshore wind
farming even in depths of 60 m.
Plans of offshore wind farms demanded within the EEZ are listed in the LOIZ
research and studies number 36 (Lange et al. 2010 ).

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