Author(s): Shigeki Sakai; Kohta Hanai
Keywords: No Keywords
Abstract: The dispersion relation of waves propagating in ice-covered sea differs from that in open water. Liu et al. (1989) showed that the relation between the wave length observed by SAR and the wave period measured by an accelerometer installed on a buoy in the Labrador Sea very closely approximates the theoretical dispersion relation of waves under an infinite-length elastic floating plate. In their model experiment, Sakai et al. (1993) demonstrated that applicability of the theoretical dispersion relation depends on the ice plate size. However, discussion has not yet addressed quantitative evaluation of the effect of ice on the dispersion relation. It is essential to consider the effects of ice when investigating the dispersion relation in ice-covered seas when dealing with various phenomena in such icy sea areas: the estimation of external force against coastal structures induced by the impact of ice floes moved by wave forces, and the calculation of behavior of spilt oil in icy sea regions. Thus, the present study investigates celerity (phase velocity) characteristics of waves that propagate in a model sea area covered with ice. It also examines ice plate length and thickness effects and elastic coefficient effects on the dispersion relation. On the basis of results of these examinations, we propose an empirical equation for the dispersion relation that can express these characteristics and effects comprehensively.