APPLICABILITY OF A REVISED LONG-TERM WAVE HINDCAST SYSTEM CONSISTING OF MSM-BASED WINDS DATA SET AND BACKWARD RAY TRACING WAVE MODEL IN THE JAPAN SEA

Abstract

 A long-term wave hindcast system which consists of a sea winds data set and a backward ray tracing wave model is revised by replacing the ECMWF or NCEP/NCAR reanalysis winds data set with the MSM(Meso Scale Model)-based winds data set opened to the public domain by JMA(Japan Meteorological Agency). The new winds data set is produced with a much higher time and space resolution than the previous one. The revised system is applied to a 12-year wave hindcasting at each of 15 coastal stations and 3 northern offshore stations in the Japan Sea and accuracy of the system is investigated based on a comparison between hindcasts and measurements for wave heights or wave periods. Main results are as follows: 1)In the semi-closed Japan Sea where local wind-generated waves are dominant, introduction of the MSM winds data set into the system leads to a more accurate evaluation of the long-term wave conditions, even if a more advanced wave model is not used. In this connection, mean value of the correlation coefficient for wave heights is 0.95 and that for wave periods is 0.85. These values are 0.04-0.08 larger than the previous values. 2)Area-dependency of wave hindcasts is not detected to an improved degree, and the effect of annual step-wise sophistication of the MSM on the accuracy of evaluated waves may not be clear.