Analysis of a low-level coastal jet off the western coast of Norway

Abstract

Offshore wind installations depend strongly on an improved knowledge of the atmospheric and ocean conditions affecting the marine atmospheric boundary layer (MABL). In particular the better understanding of atmospheric phenomena that are related to extreme atmospheric and sea state conditions e.g. high levels of wind speed, wind shear, waves and turbulence, is crucially important for offshore applications. This study investigates a low level coastal jet off the Western coast of Norway on 20 March 2011, using both in situ data and model results. The analysis is focused on parameters that are relevant to wind energy such as wind speed, turbulence intensity and wind shear. The jet is characterized by high wind speeds, moderate turbulence intensity and significant high wind shear. Furthermore, the structure and the dynamical characteristics of the low level coastal flow are investigated from the model results. The results show a maximum wind speed, greater than 30 m/s, between 500 to 800 m height above the sea level and at 15-20 km distance from the coast.