| 释义 |
downburst
down·burst D0365000 (doun′bûrst′)n. A powerful downward air current from a cumulonimbus cloud, typically associated with thunderstorm activity.downburst (ˈdaʊnˌbɜːst) n (Physical Geography) a very high-speed downward movement of turbulent air in a limited area for a short time. Near the ground it spreads out from its centre with high horizontal velocities. Also called: microburst Translationsdownburst
downburst A local high-velocity downward movement of air mass flowing out of a thunderstorm. It is the chief cause of severe wind shear. The size of a downburst may vary from a ¼ mile to more than 10 miles. It can last from 5 to 30 minutes. The wind speed can go as high as 120 knots. It is potentially very dangerous, especially during the takeoff and landing phases. |