What are katabatic winds in Antarctica?
The air flow gets stronger, turning into fast-flowing winds called katabatic winds. These katabatic winds roar toward the coast of Antarctica. Fairly quiet conditions turn instantaneously, with katabatic winds reaching speeds of 15 to 20 meters per second (50 to 66 ft/sec)!
Where are katabatic winds the strongest in Antarctica?
Wind. The strong winds of Antarctica are called katabatics, formed by cold, dense air flowing out from the polar plateau of the interior down the steep vertical drops along the coast. It is at the steep edge of Antarctica that the strong katabatic winds form as cold air rushes over the land mass.
How long do katabatic winds last?
It may blow continuously for several days at a time, with velocities that average about 74 km (about 45 miles) per hour, and reach to a height of 2 to 3 km (about 1.2 to 1.9 miles).
How are katabatic winds formed?
Katabatic winds occur when air is cooled from below over sloping terrain. Such cooling causes a shallow blanket of air adjacent to the surface to become colder and therefore heavier than the atmosphere above, thus forming a thermally distinct layer that exchanges little energy with the overlying air.
What is the impact of katabatic wind?
Since the katabatic winds are descending, they tend to have a low relative humidity, which desiccates the region. Other regions may have a similar but lesser effect, leading to “blue ice” areas where the snow is removed and the surface ice sublimates, but is replenished by glacier flow from upstream.
Are katabatic winds warm?
Though generally cold, katabatic winds can also be warm or hot. This is because as the air moves downhill and is compressed it warms (the katabatic wind would start out cold but become warmer as it moves downhill). A chinook (foehn) wind is a warm dry down slope wind.
How does katabatic wind cause frost?
Cold and usually dry katabatic winds, like the Bora, result from the downslope gravity flow of cold, dense air. The gentler katabatic flows of hill slopes produce frost hollows. Mountain breezes are part of a local wind system.
How does the katabatic wind cause frost?
Why are katabatic winds so powerful in Antarctica?
Picture liquid being poured into a funnelwhen the air flow of interior winds converges, more air is being compressed into a smaller channel space. The air flow gets stronger, turning into fast-flowing winds called katabatic winds. These katabatic winds roar toward the coast of Antarctica.
How did the katabatic wind get its name?
Katabatic wind. A katabatic wind (named from the Greek word κατάβασις katabasis, meaning “descending”) is the technical name for a drainage wind, a wind that carries high-density air from a higher elevation down a slope under the force of gravity. Such winds are sometimes also called fall winds; the spelling catabatic winds is also used.
What is the fastest wind speed in Antarctica?
In fact, Antarctica holds the record among continents for sustained wind speeds; wind speeds can reach 200 mph here. Most research teams, like ours, learn to deal with the wind; other teams actually spend their days in Antarctica studying wind.
How is the wind field in Antarctica determined?
In Antarctica, by contrast, the wind is still intensely cold. The entire near-surface wind field over Antarctica is largely determined by the katabatic winds, particularly outside the summer season, except in coastal regions when storms may impose their own wind field.