Offshore winds and tubes go together like peanut butter and jelly on our best days. Onshore winds tend to kill that party. Every surfer knows this. But according to scientists from the Scripps Institution of Oceanography, no surfer has ever made an effort to study it with scientific applications. The folks at Scripps have been full of ideas like this through the years.
The fixed bathymetry of the pool coupled with the repeatability and predictability of the wave itself made the Surf Ranch an ideal place for the study. To make it even more perfect, the wind can be both onshore and offshore with the literal flip of a switch since its foil runs the length of the pool in one direction to create a right and then back in the opposite direction to create a left not even a minute later.
“Wave models to date have not included these wind effects,” said Scripps oceanographer Falk Feddersen, who led the study. “Surfers know when wind is offshore, the surf is generally better than onshore. This is common surfing wisdom, but it has not been something that has been scientifically studied.”
“Beyond what this means to surfers, the strength and direction of the wind interests scientists in how it influences nearshore ocean physics,” UC San Diego’s Robert Monroe wrote. “Wind influences how breaking waves generate, and subsequently how sand is picked up from the seafloor under breaking waves. Ultimately wind-effects on waves may play a role in what beaches and surf zones look like.”
Now, if you think there isn’t much science you could plug into observing waves and wind direction you’re in for a surprise. The entire analysis of the project is very thorough. More than ten sections outline everything from the bathymetry of the pool to which instruments they used to measure wind direction and speed at precisely 16 meters above the surface of the water, and more. They used light detection and ranging (LIDAR) technology to observe and model the shape of breaking waves, drones to record them, mounted cameras, and the list goes on. Researchers waited approximately three to eight minutes between waves, recording and measuring the shape of 22 qualifying waves (11 rights and 11 lefts), recreating models of the mid-point of its face, the barrel, and mapping its overturn when breaking with offshore versus onshore winds.
“As wave-overturning shape impacts turbulence, bubble entrainment and sediment suspension, cross-shore wind may lead to downstream effects on sediment transport and beach morphology,” the scientists wrote in their summary. In short, they learned a bit more about what we already know: “offshore wind tends to encourage development of the tubular barrel waves favored by advanced surfers.”
