microburst

microburst
/muy"kreuh berrst'/, n. Meteorol.
an intense, localized downdraft of air that spreads on the ground, causing rapid changes in wind direction and speed; a localized downburst.
[1980-85; MICRO- + BURST]

* * *

 pattern of intense winds (wind) that descends from rain clouds, hits the ground, and fans out horizontally. Microbursts are short-lived, usually lasting from about 5 to 15 minutes, and they are relatively compact, usually affecting an area of 1 to 3 km (about 0.5 to 2 miles) in diameter. They are often but not always associated with thunderstorms (thunderstorm) or strong rains. By causing a sudden change in wind direction or speed—a condition known as wind shear—microbursts create a particular hazard for airplanes at takeoff and landing because the pilot is confronted with a rapid and unexpected shift from headwind to tailwind.

      In arid regions, the rain commonly associated with microbursts often evaporates before the downdraft reaches the ground; the resulting dry microbursts produce no visible clue to their presence. Wet microbursts, typical of more humid areas, are generally accompanied by a visible rain shaft. Bursts can be detected by modern weather radar and by wind sensors on the ground. The mechanics of microburst phenomena are not yet completely understood. Their existence was first observed in 1974 by meteorologist T. Theodore Fujita (Fujita, T. Theodore), and since then they have been identified as the cause of several airline crashes.

* * *


Universalium. 2010.

Игры ⚽ Нужен реферат?

Look at other dictionaries:

  • Microburst —   [ maɪkrəʊbəːst] der, (s)/ s, amerikanische Bezeichnung für eine Fallbö mit geringem Durchmesser (maximal etwa 5 km), die den Start oder Landevorgang von Flugzeugen erheblich gefährden kann. Innerhalb einer kurzen Flugstrecke ist dabei ein… …   Universal-Lexikon

  • microburst — [mī′krō bʉrst΄] n. a type of localized downdraft, often associated with thunderstorms, producing very strong, short lived wind shears …   English World dictionary

  • Microburst — Illustration of a microburst. Note the downward motion of the air until it hits ground level. It then spreads outward in all directions. The wind regime in a microburst is opposite to that of a tornado …   Wikipedia

  • microburst — The strong downdraft that spreads horizontally just above the ground to form a sharply defined gust front. An aircraft approaching this microburst or gust front may encounter a headwind followed by a strong downdraft and finally end up with a… …   Aviation dictionary

  • Microburst — Nasser Downburst in Gestalt eines Niederschlagsvorhangs mit Ausfließen am Boden Ein Downburst ist eine schwere Fallböe, die meist bei Gewittern auftritt, aber auch bei Schauern vorkommen kann. Hierfür sind zwei verschiedene Mechanismen… …   Deutsch Wikipedia

  • Microburst — Mi|cro|burst [ maikrəubə:st] der; [s], s <aus gleichbed. engl. amerik. microburst zu engl. micro (vgl. ↑mikro...) u. burst »Bruch, Ausbruch«> den Start od. Landevorgang von Flugzeugen gefährdende Fallbö (Luftf.) …   Das große Fremdwörterbuch

  • microburst — noun Date: 1981 a violent short lived localized downdraft that creates extreme wind shears at low altitudes and is usually associated with thunderstorms …   New Collegiate Dictionary

  • microburst — noun A strong downdraft, of less than 2.5 miles in diameter, that can cause damaging winds …   Wiktionary

  • microburst — n. violent and strong localized air current that hits the ground and creates extreme wind shears at low altitudes (generally associated with thunderstorms) …   English contemporary dictionary

  • microburst — noun a sudden, powerful, localized air current, especially a downdraught …   English new terms dictionary

Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”