Comments on 'A Global Climatology of Wind-Wave Interaction'

摘要

Hanely et al. (2010) aims at presenting a valid climatology of "wave age" for the entire World Ocean, emphasizing in particular "the wave-driven regime" (i.e., the regime dominated by strong swell). Then the question of proper definition of wave age becomes crucial. In the literature, the following four variants appear: c_p/U_(10), c_p/(U_(10) cosθ), c_p/u_* and c_p/(u_* cossθ), where c_p is the phase speed of the waves at the spectral peak, U_(10) is the wind speed at 10 m, u_* is the friction velocity, and θ is the angle between the wind and the direction of propagation of the dominant waves. Inclusion of the cosθ term is loosely motivated by "the need to take into account the component of the wind" (or, in the case of u_*, the component of the stress vector) in the direction of wave propagation (see below).