Analysis 02: OWF Effect on the Ocean - On the Effect of Offshore Wind Farms on the Atmosphere and Ocean Dynamics - page 103

adapted in the case of a complex OWF arrangement. Hence, for studies of the North
Sea under planned OWF construction in 2030, METRAS wind farm approach is
necessary.

5.3.5 Analyzing OWF Effect on the Ocean in Case of Full
Meteorological Forcing

Previous exposures of simulations dealing with the wind farm s impact on the

ocean only consider effects of the forcing variables wind and pressure, indicated
as the most important variables for analysis of the OWF effect on the ocean. But the
whole atmosphere influences the ocean in reality, and based on the fact that wind
turbines even influence temperature and humidity fields of the atmosphere, it will
be investigated here how strong these additional forcing components affect the final
phenomenon. But it must be noticed that the indirect forcing only allows influences
of the atmosphere on the ocean and not the backward feedback. Due to the eminent
change of sea surface temperature (SST), a grand question is rising and already not
outstanding at all: how strong the back coupling would affect the atmosphere,
especially the interaction between the ocean and the atmosphere? Based on
model construction, usable infrastructure, and time scope, only the analysis of
atmosphere impacts on the ocean is treated here. Full meteorological forcing for
HAMSOM comprises wind speed, surface pressure, temperature, and humidity in
10-m height, cloudiness, and precipitation. Here METRAS simulation results of
forcing were chosen to be cloud free without precipitation. Therefore, only tem-
perature and humidity will have an additional impact on the ocean in that analysis.
Corresponding simulations for the presentation are the master simulation T012ug08
TS01HD60F01 , including only pressure and wind forcing, abbreviated to F01, and
simulation T012ug08 TS01HD60F03 , including full forcing, shortened to F03.
METRAS simulations are based on an SST of 15 C and temperature at bottom
of 15.59 C. Figure 4.2 in Chap. 4 shows that a wind farm changes not only the wind
but also temperature distribution, as well as humidity. As mentioned, previous
results are only based on induced changes in the wind field, which mainly drives
the effects in the ocean, but changed temperature and humidity conditions also
impact the ocean

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s evaporation and heat exchange as an interaction between the
ocean and the atmosphere. Such interaction won

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t result in a new dynamic pattern
but can influence the temperature and salinity fields in the upper layers.
Heat and fresh water enters into HAMSOM through the source terms in the
transport equation of temperature, respectively salinity. The source term of tem-
perature consists of the total heat flux, which acts into the ocean at surface (into the
first model layer), and from there, the effect of insolation at surface can penetrated
into the ocean depths. Due to those, deeper layers can also indirectly gain heat from
the atmosphere. The source term of salinity is calculated by the difference between

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