摘要
海底摩擦不仅涉及海洋环流、潮汐和风暴潮的能量耗散等海洋动力学的主要问题,而且还与海底冲蚀、沉积等海洋地质、地貌问题有关。此外,对于长期以来盛行的用全流方程研究海洋动力学问题,底摩擦的正确描述和表达是必不可少的。
Frequently used in theoretical and observational study in ocean dynamics,the empirical hypothesis of linear dependence of the bottom frictional stress upon surface wind stress and total transport in a shallow water may be justified with success by means of a simple air-sea planetary boundary layer model under the quasiequilibrium state of forces in a nonrotating flow.The point in question is generalized in a rotating case and is compared with that obtained from routine ocean dynamic model.The difference between the results derived from the two models is briefly reported.We discuss here in some detail the effects of latitude,depth as well as eddy viscosities of air and sea which are inherent in the bottom frictional stress.Prom the viewpoint of air-sea interaction,the eddy viscosity and the density of air play an effectual role in the influence of atmosphere on the sea-bed friction.Derived in this paper are the non-linear total transport equations comprising the bottom friction which govern storm surges and tides in the air-sea planetary boundary layer model as well as in the routine ocean dynamics.Although the bottom friction seems to be somewhat complicated,the two-dimensional equations of motion thus obtained prove to be superior in affording facility for data acquisition to the others.There are three effects induced by the bottom friction,namely that on the bottom resistance,that on the atmospheric forcing functions on the water and that on the Coriolis effects.Factors controlling the mechanical energy in the sea are physically analysed.The latitude,the depth and the eddy viscosity of the sea included in the bottom friction are all of great importance in dissipating the currents and the kinetic energy and in governing the behaviour of the inertial currents,whereas the eddy viscosity of air plays a small role in comparison with that of the sea.This effect tends to be taken into consideration,especially in determining the frequency or the period of the inertial flow.
作者
秦曾灏
Qin Zenghao(Shandong College of Oceanology)
出处
《海洋与湖沼》
1981年第1期9-24,共16页
Oceanologia Et Limnologia Sinica
