Piteraq

A piteraq is a cold katabatic wind which originates on the Greenlandic icecap and sweeps down the east coast. The word "piteraq" means "that which attacks you" in the local language.[1] Piteraqs are most common in the autumn and winter. Wind speeds typically reach 50 to 80 m/s (180–288 km/h; 111–178 mph).

Causes

The Greenland ice sheet cools the air directly above it. Colder air is denser and it sinks, forming a separate layer of cold air in between warmer air. A piteraq is triggered by low pressure systems off the east coast of Greenland. Piteraqs do not only affect coastal towns, but also large areas of sea to the east of Greenland.

On February 6, 1970 at about 6:00 PM, the community of Tasiilaq was hit by the worst documented piteraq ever in Greenland (estimated at 90 m/s — about 325 km/h or 200 mph) (Stronger than a category five Atlantic hurricane) causing severe damage.[2] Since the beginning of 1970, special piteraq warnings have been issued by the Danish Meteorological Institute.

Although piteraqs can be caused by low pressure systems of the east coast of greenland, their formation is a combination of several factors: The temperature on the Greenland ice sheet, the conditions in the fjords and the current atmospheric conditions. When a low pressure system is approaching the coast of Greenland it generally has strong winds that can suck in air off the Greenland ice sheet, causing a Piteraq.

Current research

Due to the fact that Piteraqs occur in a isolated and sparsely populated area scientist's do not know much about how they function, but that is starting to change as more and more researchers are heading to Greenland to understand these winds.

See also

References
  1. Danish Meteorological Institute, The Observed Climate of Greenland, 1958–99, p. 96
  2. ibid., pp. 96–98
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