DIFFERENCES OF FREQUENCY CHARACTERISTICS OF INFRAGRAVITY WAVES OBSERVED ALONG AND OFF JAPANESE COASTS

Abstract

 In this paper, we investigated differences of frequency characteristics of infragravity waves observed at 20 coastal wave stations and 15 offshore GPS buoy wave stations. Shorter components whose periods are less than 150s exist only in shallow areas whose depth is less than 250m and their temporal variations are large depending on occurrence of meteorological disturbances. On the other hand, longer components whose periods are more than 300s exist in all areas and their temporal variations are small.