Analysis 02: OWF Effect on the Ocean - On the Effect of Offshore Wind Farms on the Atmosphere and Ocean Dynamics - page 113

Fig. 5.41 Map of investigation area around test wind farm alpha ventus ( black + ). Wind turbines

' '

are marked blue , CTD measurements are red marked with + , ADCP measurements green marked

' '

with , which is close to

turbine 12 and the swell buoy ( orange ' o buoy ' ). Black arrows mark direction of ship track for
CTD measurements. The CTD sections (west, north, east, south) are defined along the CTD
stations

, the sign for the Fino1 platform is

' ☐ '

, and for the relay station

' ♦ ' 'Δ'

which supports to put model results and measurements of temperature and velocity
into relation to each other.
The area around wind farm alpha ventus with measurement stations, time, and
position of data collection are represented in Fig. 5.41 . The measurements comprise
39 + 3 CTD stations and three ADCP mooring stations only taken for this analysis.
The time frame was May 11-13, 2013, at which CTD measurements were taken on
May 12 and the ADCP instruments collected data over 2 days from May 11-13.
Additional temperature and dynamical data were and are retrieved permanently by
instruments of the station Fino1, relay station, and swell buoy located in the area of
alpha ventus (Fig. 5.41 ).
A separation of ADCP-measured velocity data into its component was deemed
as the easiest way to detect upwelling and downwelling, as shown in the model data.
But the residual velocity signal in the North Sea is strongly disturbed by the tide,
which makes the analysis of velocity components difficult, as well as the fact that
changes of the vertical velocity component are small and hard to detect, even after
subtracting the tidal signals. Hence, the ADCP data taken at three positions (north,
east, and south to alpha ventus ) do not result in a distinct, with model data
comparable, signal, and thus they are only documented in Sect. 9.1.3 , for the sake
of completeness.