Afraid of flying? You’d better cross Dr. Kent Moore’s lab off your list of potential grad school placements. Moore, a physicist at UTM, returned home last week from a 21-day research expedition to the North Atlantic, where he spent most of his time flying through fierce winds above rough seas. He was on a mission to study tip jets, a special kind of air current that occurs at the southern tip of Greenland, Cape Farewell. Moore decided the best way to gather data about the tip jets was to jump right in.
Tip jets are simple but intriguing phenomena. As air flows from west to east across Canada, it encounters Greenland, an enormous land mass about 3000 metres high and 3000 kilometres long. When air flow is diverted around this huge obstacle, it can generate tremendous winds, up to 140 km/h, near Greenland’s Cape Farewell. There are two kinds of tip jets-the “forward” jets just described, and “reverse” tip jets that are formed by air flowing from east to west.
If you’ve never heard of tip jets, you’re not alone. Forward tip jets were first identified in 1999, and reverse tip jets were identified by Moore in 2003. Still, very little is known about them.
Moore’s research team, which includes scientists from Canada, Britain, Iceland, Norway and the United States, believe tip jets are more than just a curious weather quirk. Moore explained that tip jets “are a very interesting phenomenon in their own right,” but added that “they actually play an important role in climate as well.”
“We need to document the existing climate to understand the changes that are occurring in the polar regions,” Moore said.
Moore’s study focused on the tip jets’ involvement in an oceanic mechanism called the thermohaline circulation. As warm water from the equator flows toward the poles, it cools down. Because cold water is denser than warm water, the cold water sinks and returns to the equator. Only four places exist in the world where this “water sinking” occurs, and two of them are near Cape Farewell. The cause of the heat loss near Greenland has been an enigma until the discovery of tip jets. The team’s research attempts to explain how the two phenomena are related, and their data shows that tip jets efficiently remove heat and moisture from the ocean’s surface as the water approaches Greenland.
To gather these data, the team flew a custom modified research aircraft directly into the tip jets-a very turbulent ride. They measured parameters including temperature, pressure and windspeed in real-time, using sensors attached to the outside surfaces of the plane.
“The waves were being destroyed by the wind. The wind was so strong it just sheared the tops of the waves right off. It was fascinating to experience,” remarked Moore.
Though the tip jets occur in Greenland, the 30-person research team headquartered in Keflavik, Iceland, a town of about 10,000 people, where they “took over most of the hotel,” as Moore laughingly put it.
The project was launched as a part of the fourth International Polar Year, a two-year worldwide research collaboration focusing on arctic science. The IPY initiative began in the 1880s when scientists realized the need for collaboration in order to gain a real understanding of arctic climate. The last IPY was in the 1960s.
The research will also help improve weather forecasting in areas downstream from the jets, including Europe. The data gathered during this trip will improve the currently sparse understanding of complicated weather systems.
