The bright fuchsia-colored waves that were seen crashing along the shore in San Diego in the past week have been leaving the locals flummoxed. What’s going on, they ask? Now researchers have revealed just what’s causing the sudden and dramatic color change. It’s science.
Scripps Institution of Oceanography is actually responsible for the temporary color change at Torrey Pines State Beach. Researchers are conducting a study, called Plumes in Nearshore Conditions, or PiNC, to learn more about how freshwater interacts with salt water near shore. By releasing a non-toxic pink dye in the nearby Los Peñasquitos Lagoon coastal estuary, researchers say they are able to monitor what happens to that water when “small-scale plumes” end up in the surf zone along the beach, where the waves break.
This research, Scripps said, will “provide a first-ever view” of how freshwater mixes with the more dense ocean water within waves. That information, they said, is crucial for understanding how sediments, pollutants, larvae and other materials disperse throughout shorelines. The pink plume in this study will be monitored with various instruments, from land, sea and air.
The dye being used poses “no threat to humans, wildlife or the environment,” Scripps said, although civilians have been urged to not swim in the area due to the ongoing research.
Scripps coastal oceanographer and study leader Sarah Giddings called the research a “really unique experiment,” as many previous studies on this subject matter have focused on large amounts of freshwater going into the ocean. They chose Los Peñasquitos Lagoon because it’s a “prime example” of small plumes going into surf zones, she said in a news release.
“We will combine results from this experiment within older field study and computer models that will allow us to make progress on understanding how these plumes spread,” Giddings added.
According to the research project’s website, Giddings and her team hypothesize that four things could potentially be happening to the freshwater as it interacts with the ocean waves: It gets trapped in the surf zone and/or escapes as a freshwater plume; it stays within a certain parameter of the coastline; it escapes the surf zone through rip currents; or finally, that waves mix the freshwater with the ocean water next to the shore.
Giddings’ team is doing three dye releases, the first of which was on Jan. 20. Another release is planned sometime before the end of the month and another in early February.
The first experiment saw “much success,” researchers said on their website. The dye revealed that the initial plume was trapped in the surf zone but that it was eventually carried south with some of the plume getting ejected from the surf zone.
