Studying the Breeze

Understanding how ocean water evaporation affects radio waves may someday help advance long-distance communications across the Earth.

Researchers from The Ohio State University recently returned after a month-long scientific cruise in the Atlantic Ocean looking for such answers.

Based off the coast of North Carolina throughout the month of October, a group of five engineers from Ohio State’s ElectroScience Laboratory (ESL) worked as part of a multi-university research initiative (MURI) project called “CASPER,” or Coupled Air-Sea Processes and Electromagnetic Ducting Research. The project is coordinated through the Naval Postgraduate School in Monterey, California.

ESL research professor, Robert Burkholder, principal investigator (PI) on the project, led a team made up of co-PI Caglar Yardim, as well as graduate research assistants Swagato Mukherjee, Jon Pozderac, Qi Wang and Luyao Xu.

During the cruise, Burkholder said, the OSU team measured radio wave propagation in the marine atmospheric boundary layer, while others in the CASPER team simultaneously recorded atmospheric and oceanographic conditions.

He said the team was able to collect unprecedented new data.

“The subsequent data analyses will improve the knowledge base for electromagnetic ducting as well as for air-sea interaction and mesoscale forecasting,” Burkholder said. “This work will lead to better predictions of ducting conditions that can affect long-distance radio frequency communications over the ocean.”

Examples of mesoscale forecasting involve the study of squall lines, sea breezes or hurricanes.

“The goal of the five-year research program is to understand how radio waves are guided in the evaporation duct near the surface of the ocean, due to variations in refractive index, similar to how light waves are guided inside a fiber-optic cable,” Burkholder said.

He said the team successfully collected a unique dataset, with repeated electromagnetic links and corresponding environmental sampling, for quantifying air-sea interaction processes and electromagnetic ducting in the near shore region and over the Gulf Stream. 

Xu said they divided up their time on the water.

“The experiment lasted for a whole month,” she said. “Our group of five switched for two legs, each with half a month.”