Maps that help people visualize ocean currents can be used to address environmental problems such as oil spills, for search and rescue missions, or even to plan military operations. These maps are made possible through the work of physical oceanographers such as A. D. Kirwan, Jr., Mary A. S. Lighthipe Chair in Marine Studies and director of the Physical Ocean Science and Engineering Program at the University of Delaware’s College of Marine Studies.
On Thursday, August 21, at 7:00 p.m., at the College of Marine Studies’ campus in Lewes, Kirwan will discuss his research in a talk titled “Where Do Currents Come from and Where Do They Go?” Kirwan’s presentation is part of the Ocean Currents Lecture Series, which is held monthly at the Lewes campus through September.
In his presentation, Kirwan will give a brief description of the forces that generate ocean currents. In addition, he will share the results of his research in the Gulf of Mexico and Monterey Bay, California, to show how ocean current maps are generated.
In the Gulf of Mexico, the currents are driven by very large eddies having diameters that are on the order of 100 miles or more. Observations of current velocity at discrete points in time are obtained by satellites, aircraft, ships, and buoys. Scientists then use this information in a computer model. As observations are updated, the model is modified accordingly.
“The processes that govern the motion of water in Monterey Bay are completely different from those in the Gulf of Mexico,” says Kirwan. “For example, the eddies are much smaller — approximately one mile in diameter. In addition, the water motion is complicated by variations in the bottom topography as well as strong winds and tides.”
The rapidly changing currents in the Monterey Bay region are measured by high-frequency radar, which has the capability of measuring ocean currents at numerous locations. Physical oceanographers fill in any spatial gaps through a process called “objective mapping” to estimate current velocity.
A member of UD’s faculty since 1999, Kirwan earned his doctorate from Texas A&M University in 1964 and his bachelor’s degree from Princeton University in 1956. His book Mother Nature’s Two Laws: Ringmasters for Circus Earth, published by World Scientific, introduces nonscientists to thermodynamics and explains how this science can be used to understand issues such as global warming and the practicality of electric cars. Kirwan also has written more than 70 peer-reviewed publications.
The lecture will begin at 7:00 p.m. in Room 104, Cannon Laboratory, at the Hugh R. Sharp Campus, 700 Pilottown Road, Lewes. The hour-long talk will be followed by light refreshments.
While the lecture is free and open to the public, seating is limited and reservations are required. To reserve your seat, please contact the college at (302) 645-4279.