By Brian Gilliland

LEWES — By studying the interplay of the top layers of ocean and the bottom layers of atmosphere, a team led by the University of Delaware’s Dr. Andrew Wozniak hopes to increase understanding of climate models.

That mission is being bolstered by an expedition to the continental shelf that launched from Lewes on Sunday.

“We’re sampling different environments to see the differences,” Dr. Wozniak said. “We’re starting just off the Delaware Bay, then out to the continental shelf and open ocean.”

He and his team are studying the millimeter-thin layer between the surface of the ocean water and the atmosphere, a layer full of things like plankton and pollutant residue, to see how the surfaces interact and influence each other.

“It’s the ocean’s skin. We’re exploring how the chemistry of seawater is influenced by phytoplankton, to see how quickly gas and particle exchange occur,” he said.

“There’s the carbon dioxide plants need to grow, oxygen, methane, nitrogen dioxide and pollutants like sulfates and nitrates from burning fossil fuels.”

In the models currently used for such measurements, there are deviations, Dr. Wozniak said, and the suspicion is that changes in the microlayer are at least partially responsible.

But how to measure it? The team designed and constructed a rig to be dragged along behind the expedition’s vessel. The device features several panes of glass mounted perpendicular to a circular frame. As the boat moves along the water, the equipment should capture the layer’s residents and compounds on the glass, leading to recovery and testing of the material.

“If you see a rough surface or a slick on the water, those are areas of surfactant compound buildup (that) change exchange rates,” he said.

But that’s just a piece of the puzzle.

“This is the measurement phase. The rates are important for climate change models, and in the ocean over such a large area, it’s important to understand just how things are going back and forth,” Dr. Wozniak explained.

There have been some challenges facing this mission, starting with when it began: It was originally scheduled for November 2022.

“We got two days in, but then, we had another hurricane, so we looked at the forecasts and said forget it,” Dr. Wozniak said. “Mechanical issues with the ship stalled us last year, and we had some more this summer,” delaying the trip at the end of last month. Plus, its return date depends on the weather.

But Dr. Wozniak said he and his team know the value of patience.

“It’s important to understand how all the oceanic and atmospheric processes are linked together because our understanding of complex problems comes from understanding all aspects of the issues,” he said.