Mapping optical ray trajectories through island wake vortices

• Published in: Meteorology and atmospheric physics Vol. 127; no. 3; pp. 355 - 368
• Main Authors: Nunalee, Christopher G., He, Ping, Basu, Sukanta, Minet, Jean, Vorontsov, Mikhail A.
• Format: Journal Article
• Language: English
• Published: Vienna Springer Vienna 01-06-2015; Springer Nature B.V
• Subjects: Aquatic Pollution; Atmosphere; Atmospheric Sciences; Earth and Environmental Science; Earth Sciences; Math. Appl. in Environmental Science; Meteorology; Original Paper; Propagation; Terrestrial Pollution; Waste Water Technology; Water Management; Water Pollution Control; Wave propagation; Wake Region; Planetary Boundary Layer; Vortex Street; Wake Vortex; Vertical Vorticity
• ISSN: 0177-7971; 1436-5065
• DOI: 10.1007/s00703-015-0366-4

Optical wave propagation through the atmosphere is complicated by organized atmospheric structures, spanning a wide range of length and time scales, which induce spatio-temporal variability in refraction. Therefore, when considering long-range optical ray trajectories, the influence of such structures on the propagation path becomes significantly more complex compared to a hypothetically homogeneous atmosphere. In this paper, we use a coupled mesoscale model and ray tracing framework to analyze the refractive anomalies associated with the wake vortices induced by three geographically diverse islands under various meteorological conditions. We identify organized mesoscale wake vortices (e.g., von Kármán vortices) which are sometimes capable of distorting optical ray trajectories, through ray bending, tens of meters at a range of approximately 50 km. In addition, we find in some cases that vertical oscillations, or perturbations, to the simulated ray trajectories share a frequency with the vortex shedding frequency on the order of hours. At the same time, it is also observed that the intensity and predictability of the wake vortex-induced ray bending varies from case to case. Collectively, these results highlight the value of using mesoscale models in optical wave propagation studies above conventional approaches which do not explicitly consider horizontally heterogeneous atmospheres.