Cooperative Education and Internship Program (CEIP)College of Engineering 

SMAST Researchers Funded to Study Effects of North Atlantic Oscillation

Drs. Avijit Gangopadhyay and James Bisagni have been awarded $450,000 by the National Science Foundation to investigate the effects of climate change on marine ecosystems.

The two scientists, who hold joint appointments in the Physics Department and the School for Marine Science and Technology, will use computer models and ocean observations to study the effects of the North Atlantic Oscillation (NAO) on marine life. The NAO is an atmospheric phenomenon that is responsible for much of the weather and climate variation over the North Atlantic and surrounding continents.

"Everybody has heard of El NiƱo," says Gangopadhyay, who is heading up the project, "and how it affects weather around the globe. The North Atlantic Oscillation also has far-reaching effects on weather and climate, from eastern North America to eastern Asia, but it hasn't received the same degree of press coverage."

The NAO is a kind of atmospheric "seesaw" between two pressure centers over the North Atlantic--one over Iceland and the other over the Azores. Each pressure center is the center of a wind system, and changes in the pressure centers modulate winds as well as the intensity, frequency, and pathways of storms."

Year-to-year variations in the NAO explain much of the year-to-year variation in weather both here and in Europe--for example, why we may face a cold, dry winter one year, and a warm, wet winter the next. Longer-term NAO variation is responsible for more enduring phenomena, such as the so-called "cold 1960s" and "warm 1980s," memorable stretches that are well documented in weather records as well as in personal anecdotes.

"Our family dentist told me that he actually moved from Massachusetts to California in the 1960s because it was too cold here," Gangopadhyay recalls. "Then he came back in the 80s, when he heard it had warmed up."

These fluctuations affect not only the lives of dentists, but also the lives of marine species. Gangopadhyay and Bisagni are targeting a type of small crustacean called a copepod to model the NAO's effects on marine ecosystems.

Copepods are the most numerous multi-celled creatures in the oceans, and a large part of the marine food web. Their response to climate change will in turn affect the response of the other forms of marine life that depend on them, directly or indirectly, including species of commercially important finfish.

"Understanding long-term variability in the oceans is crucial to sound ecosystem-based fisheries management," Gangopadhyay notes. "Management strategies that work well under one NAO regime may fail under a different regime."

The project is part of the GLOBEC (Global Ocean Ecosystems Dynamics) program, a decade-long study of marine ecosystems and how they respond to changes in their physical environment. GLOBEC was launched in response to accumulating evidence of climate shifts in Earth's history and the possibility of a coming climate shift caused at least in part by human activities.

Author: "Smast"
Date: 22-3-2006

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