Effects of Buoyancy on Langmuir Circulation

Based on the Navier--Stokes equation, an equation describing the Langmuir circulation is derived by a perturbation method when the influences of Coriolisforce and buoyancy force are both considered. The approach used in the analysis is similar to the works carried out by Craik and Leibovich [J. Fluid Mech. 73(1976)401], Leibovich [J. Fluid Mech. 79(1977)715] and Huang [J. Fluid Mech. 91(1979)191]. Potential applications of the equation proposed are discussed in the area of Antarctic circumpolar current.