Exploring local variations in optical turbulence in a coastal environment with mesoscale model simulations and comparison with experimental results

For the investigation of laser beam propagation over the sea, an experimental field campaign was conducted from August 12th to 23rd, 2024, over the North Sea, between Den Helder and the island of Texel (The Netherlands). This article focuses on characterizing the atmospheric conditions, particularly the key atmospheric parameter that interferes with laser propagation, the refractive index structure parameter 𝐶_𝑛². This parameter provides a measure for the strength of optical turbulence. Scintillometers monitored the integrated optical turbulence over the laser propagation path of 3.6km. Additionally, ultrasonic anemometers provided point measurements at both ends of the laser propagation path on the coast. In addition to the field measurements, simulations were performed using the Weather Research and Forecasting (WRF) model at a horizontal resolution of 1.1km. The results of the WRF simulations were coupled with a parametrization scheme to derive 𝐶_𝑛². The WRF results are compared with the experimental findings to examine whether the WRF simulations in this configuration can accurately represent the conditions of optical turbulence in this coastal and marine environment. Preliminary results from both experimental and modelling efforts will be presented and discussed.