IMPROVING RESOURCE ASSESSMENT OF WAVE POWER BASED ON SPECTRAL WAVE MODEL

Epistemic uncertainties of wave power estimation based on spectral wave model were assessed utilizing the community wave model WW3 of NOAA. A four tiered nested model was constructed covering the Pacific Ocean, the sea around Japan, the North-Eastern Japan and Kamaishi regional model at 100km, 10km, 1km and 100m resolutions respectively. The sensitivity of the model output to four wind products (NCEP-GFS ， NCEP-CFSR ， GSM/JMA ， ERA-interim/ECWMF) was tested; the wave model outputs as well as wind products were validated against observations of NDBC buoys, JKEO/JAMSTEC buoy, TAO array and NOWPHAS buoy along the north-eastern Japan. The differences of the estimations using four wind products were relatively small whereas model errors were spatially inhomogeneous. The dependence on grid-resolution was relatively small at depth 100m or so. On the other hand, the modeled significant wave period had a large bias from the observation because of the inconsistency in the spectral moment used to estimate the significant wave period. The energy period (T-1,0) was 5 % larger than the period from WW3 (T-0.5,0) and 20 % larger than the period from NDBC (T0,2). The difference of wave period, dependent on the spectral shape and location, are often overlooked despite their significant impact on the resource estimate