September 18, 2023 — Every year, as the surface water temperature off the United States’ mid-Atlantic coast rises steadily from late spring through the summer, a pocket of uncharacteristically cool and crisp water gets trapped at the bottom of the ocean. Packed with nutrients, this thick band of cold water, known as the mid-Atlantic cold pool, is a vital home for shellfish species like surf clams and sea scallops. Extending at its seasonal peak from Nantucket, Massachusetts, to Cape Hatteras, North Carolina, the cold pool fosters a diverse ecosystem ranging from small algae to migratory fish—and some of the most valuable shellfish fisheries in the United States.
The mid-Atlantic cold pool has been a reliable oceanographic feature for more than 1,000 years. Nowhere else in the world can you find such a large summer temperature difference between the water at the ocean’s surface and at the bottom. Now, however, two pressures have scientists worrying about whether the cold pool will persist. The first is no surprise: climate change. Over the past five decades, climate change has destabilized the cold pool, causing it to warm and shrink. Compared with 1968, the cold pool is now 1.3 °C warmer and has lost more than one-third of its area.
The second concern is less intuitive and less certain. In 2023, the US federal government approved plans to install 98 wind turbines off the New Jersey coast, covering an area of more than 300 square kilometers. Construction is slated to start this fall and the completed project should have a capacity of about 1,100 megawatts. That’s enough to power roughly 380,000 homes. Yet anchoring so many turbines to the seafloor could have unexpected consequences for the temperature stratification that keeps the cold pool intact. That’s why Travis Miles, a physical oceanographer at New Jersey’s Rutgers University, and his colleagues are investigating how the budding wind farm might affect how and when the cold pool forms and breaks down.