On the Effect of Topography on the Helmholtz Wave. IV

[摘要] The author has treated the effect of the stable vortices caused by a semicylindrical mountain range on a flat plain upon the wave length, amplftude and frequency of the Helmholtz wave. The wave length K is expressed by the amplitude L by L=1/H, and frequencies of stable wave length and amplitude of the Helmholtz wave by x=1/K, x=H if we consider those of infinite as unit.The conclusion drawn is as follows:- Behind the stable vortex the stable wave length and amplitude of the Helmholtz wave are respectively minimum and maximum, upon the stable vortex they are entirely opposite and in the winlward they take middle in the former and the latter places. The frequencies of stable wave length and amplitude of the Helmholtz wave are reciprocally proportional to stable wave length and amplitude of Helmholtz wave respectively.In other wards the stable Helmholtz Wave wi_??_h large amplitude and short wave length is frequent in the region behind the stable vortex, next in the windward and the unstable Helmholtz wave with short wave length and small amplitude is probable in the domain upon the stable vortex.The above effects depend upon the strength of the stable vortex, that is, the position of it.The stronger the strength of it, the larger the effects and the ampler the affected domain, especially these influence extends to far distance in the sea-side of it.

[学科分类] 大气科学