jet stream
[f. jet n.3 + stream n.]
a. A fast-moving, relatively narrow stream of fluid that is present as a current in an atmosphere or ocean; spec. in Meteorol., a strong wind confined to a narrow region of the atmosphere, esp. one in the upper troposphere at middle latitudes that blows in an approximately horizontal direction, predominantly from west to east.
| 1947 Bull. Amer. Meteorol. Soc. XXVIII. 255 During periods of reasonably straight west wind circulation over the North American continent, there exists normally, at levels between 5 km and 15 km above sea level, a fairly narrow zone of extremely strong west wind circulation (jet stream), reaching its maximum intensity and sharpness at the tropopause level. 1950 Time 29 May 70/2 Six miles up, where the air is thin and cold, a fearful wind zigzags round the earth at 200 m.p.h. Meteorologists call it the ‘jet stream’. 1957 G. E. Hutchinson Treat. Limnol. I. iv. 225 The jet-stream mechanisms believed to maintain circulation in the region of the westerlies. 1963 tr. E. R. Reiter's Jet-Stream Meteorology iv. 271 (heading) Jet streams in the oceans. Ibid., The current does not spread out..but it remains concentrated in a narrow band of high velocities—the oceanic jet stream. 1971 New Scientist 8 Apr. 90/2 In the tropopause..there is a meandering hemispheric band of high speed westerly winds, called the jet streams. |
b. A jet of fluid (jet n.3 4), esp. one ejected by a jet engine.
| 1955 Sci. News Let. 5 Mar. 160/3 Graphite lubricant is propelled in a jet-stream reaching many often inaccessible trouble spots. 1955 Ibid. 26 Mar. 200/1 These air whirlpools are not caused by either the propeller backwash or jet stream, but by the action of the plane's wings. 1959 S. N. Samburoff tr. Feodosiev & Siniarev's Introd. Rocket Technol. vii. 232 The presence of the jet stream..introduces certain specific peculiarities into rocket aerodynamics. 1962 H. E. Newell Express to Stars iii. 29 It takes a force to expel material into a jet stream..and by Newton's law of reaction there must be a reaction force. |