The global pattern of atmosphere circulation.

Winds

Winds in the Arctic blow in mainly from the west as part of the westerlies, the name given to the main pattern of atmospheric circulation in the Northern Hemisphere. Wind speeds in the western Arctic are generally lower than in the east. In Davis Strait, wind storms lasting two or three days per month are a common phenomenon each month throughout the winter.

What Causes Wind?

Wind may be caused either by pressure differences as the atmosphere heats and cools at different rates or by changing topography. Winds blowing downslope, from high to low ground, accelerate as the air descends. Such winds reach hurricane force over the Melville Hills at the base of the Parry Peninsula, in the Amundsen Gulf, NWT. These winds may also form over the glaciers in mountainous areas of the eastern Arctic Islands. Air flowing over these icy areas cools rapidly and flows downslope under the force of gravity. In some cases, these downslope or katabatic winds are very warm. In the Arctic, warm, dry foehn winds can cause melting at the edges of glaciers, and have been recorded over the White Glacier of Axel Heiberg Island. Foehn winds can also cause short-term increases in temperature in local areas, like the Chinook winds on the easterly slopes of the Rocky Mountains. Winter temperatures at Alert, on Ellesmere Island, have jumped to 20°C for several days as a result of foehn winds.

Winds flowing upslope occur as a result of warm air rising. In the Arctic, as elsewhere, these upslope, or anabatic, winds often form as air flowing off a water body. These winds are usually quite light, and relatively warm, and are better known as summer, or sea, breezes.

Anabatic winds flow uphill. They are generally light.	Katabatic winds flow downhill. They can vary in temperature, and can reach high speeds.

Local topography affects the direction and strength of winds in the Arctic. Winds strengthen as they flow through coastal channels and mountain passes, such as those in the eastern Arctic along the Baffin Island, Devon Island, and Ellesmere Island coasts. Winds also control the movement of sea ice, affecting its concentration, area, and surface topography. Ice often blocks the entrances of narrow straits due to winds which blow strongly in these settings.

Annual prevailing wind direction and mean speed (km/h) for all hours

Sled dogs curl into tight balls to keep warm and shield their faces from harsh arctic winds.

Snowblowing

Winds blow more strongly over the flat, open areas of the central and western Arctic Islands and less over the more rugged terrain of the eastern Arctic Islands. These winds redistribute the snow cover, piling it into dunes or raking it into sastrugi (parallel ridges). The rougher the terrain, the more unequal the surface snow cover. Snow cover is relatively uniform over flat tundra and sea ice, but is generally blown away from watersheds, windward slopes, and plateaus into adjacent hollows.

Snow in the Arctic is easily wind-borne because it is not "sticky". At wind speeds of 60 km/h, blowing snow makes it difficult to see more than a few metres. With cold temperatures and windy conditions, a winter storm becomes a blizzard. In spring and fall, the snow and sky often have a uniform whiteness. Landscape and clouds blend together, causing the horizon to disappear. During these arctic whiteouts, travellers can easily lose their way.

Mean annual number of days with blowing snow