Kjetil Våge, a graduate student in the MIT/WHOI Joint Program, was lead author of a new report showing the surprising return of convection in northern seas in the winter of 2007-8.
Scientists and crew aboard the research vessel Knorr faced winds ranging from 60 to 100 knots and 30- to 40-foot tall waves on an expedition to the Irminger Sea in October 2007. (Photo by Kjetil V?ge, Woods Hole Oceanographic Institution)
In the North Atlantic Ocean, the contrast between frigid, dry winter air and warm water draws heat from the ocean into the atmosphere and leaves ocean water colder and denser. The denser waters sink and feed into the lower limb of a global system of currents often described as the Ocean Conveyor. The process, called deep convection, has far-reaching effects on climate. (Illustration by Jack Cook, Woods Hole Oceanographic Institution)
The Greenland tip jet is a sporadic jet stream characterized by fierce winds on the lee side of Cape Farewell on the southern tip of Greenland. This phenomenon appears to play a critical role in chilling North Atlantic waters so that they sink to great depths and drive part of the global ocean circulation and climate system. Using NOAA's QuikSCAT satellite, MIT/WHOI Joint Program graduate student Kjetil Våge compiled this image of a tip jet on Dec. 5, 2002. Color indicates wind speeds in meters per second; arrows indicate wind direction. (Courtesy of Kjetil V?ge, Woods Hole Oceanographic Institution)