Rip Currents Generated by Distant Typhoons at Haeundae Beach of Korea: Forecast and Warning

Abstract

A rip current warning system, which estimates the rip current risk level based on the real-time incident wave conditions measured near the beach and the database pre-calculated using the Boussinesq wave model (Choi et al., 2014), has been in operation at several beaches in South Korea. The warning system has been proved to be highly effective to reduce the rip current accidents in the beaches. However, it also suffers from the shortage of lead time of issuing the warning. In this study, the warning system was improved by forecasting the wave condition at the beach in advance with sufficiently long lead-time which was achieved by using the wave data of an ocean buoy deployed far from the beach towards the typhoon generating area. The empirical relation between the wave conditions at the two buoys was obtained to predict the wave condition at the Haeundae coast. The wave conditions predicted with 11 hour lead time agree reasonably well with those measured at the Haeundae coast.