| 释义 |
geostrophic, a.|dʒiːəʊˈstrɒfɪk|
[f. geo- + Gr. στροϕή a turning, f. στρέϕειν to turn + -ic.]
Of, pertaining to, or caused by the Coriolis force (see Coriolis); usu. applied to a wind (or a current of water) in which there is a balance between the Coriolis force and the horizontal pressure gradient (cf. gradient wind s.v. gradient a. and n. B. 6).
1916N. Shaw in Nature 4 May 210/1 The motion of air..is persistent because the pressure-gradient is balanced by the centrifugal action of the earth's rotation, which we may call the geostrophic component, and of the curvature of the path over the earth's surface, which we call the cyclostrophic component. Ibid. 211/2 We call the wind computed according to the first term the geostrophic wind, and regard it as generally representing the actual wind of temperate and polar regions. 1928D. Brunt Meteorol. vii. 66 The value of the gradient wind which is derived when the curvature of the path is neglected is called the geostrophic wind. 1933Jrnl. R. Aeronaut. Soc. XXXVII. 314 The ground wind is rarely the same in direction as the geostrophic wind which blows at 1,500 feet above the surface, and in which the airman is more likely to be flying. 1957Times Survey Brit. Aviation Sept. 7/3 Up to about 20,000 ft. the classical ‘geostrophic balance’ between the pressure and motion fields holds fairly well. 1966[see gradient wind s.v. gradient a. and n. B. 6]. 1970Sci. Jrnl. Mar. 56/1 In most ocean currents the horizontal pressure gradient is found to be in balance with coriolis force. Such currents are called geostrophic or ‘Earth-balanced’ currents. |