Models, Data, and Methodology - On the Effect of Offshore Wind Farms on the Atmosphere and Ocean Dynamics - page 14

Chapter 3
Models, Data, and Methodology

This work comprises two models and a couple of data, which are described here.
The models used are mesoscale models named HAMSOM and METRAS, which
were used to simulate the ocean and the atmosphere. Data comprise forcing data for
the simulations, as well as done measurements. Additionally, this chapter explains
the model setups and the methodology used to analyze the impact of offshore wind
turbines on the atmosphere and the ocean.

3.1 Models

3.1.1 Hamburg Shelf Ocean Model

The HAM burg S helf O cean M odel (HAMSOM) is a numerical three-dimensional
baroclinic hydrostatic dynamical model developed by Backhaus ( 1985 ). Here, a
modified version, including improvements by Pohlmann ( 2006 ), is used.
HAMSOM is well developed for sea shelf processes and tested in various studies
of the North Sea and other shelf seas such as Backhaus and Hainbucher ( 1987 ),
Carbajal ( 1993 ), Becker et al. ( 1999 ), Hainbucher and Backhaus ( 1999 ), and Huang
et al. ( 1999 ), and several more.
HAMSOM is known as an accurate model simulating physical processes well
and therefore features the best requirements for this study. Model basics are the
primitive equation, a free surface. The horizontal and vertical grid spacing is
defined in z -coordinates on the Arakawa C-grid (Arakawa and Lamb 1977 ). The
model uses a semi-implicit scheme, instead of separating the internal and external
modes, which are largely exempt from the stability criteria usually required for
explicit formulations. A further detailed description of additional HAMSOM fea-
tures is allocated in this study if necessary, for example in Sect. 5.2 , which deals
with a sensitivity study to analyze physical processes in the ocean.