Abstract
The Pacific Ocean and adjacent seas have complex wave climates influenced by local winds and distant storms. The island communities are vulnerable to coastal hazards, while having ample ocean resources to manage and protect. In support of Pacific Island communities, we have been operating a model package for forecasting and hindcasting of multi-modal sea states. Figure 1 provides a schematic for the interoperable spectral wave models driven by winds. WAVEWATCH III [1] covers the globe at 30 arc-min (~55 km) resolution and includes two-way nested regional grids at archipelagos with US and affiliated islands. The regional grids provide spectral boundary conditions for nesting of SWAN [2] at major islands to capture shelf and reef processes at resolution as fine as 3 arc-sec (~90 m).
The Global Forecast System (GFS) provides 14-day wind forecasts at 15 arcmin (~30 km) resolution [3], while the Climate Forecast System Reanalysis (CFSR) produces assimilated surface winds for the entire globe at 30 arc-min (~55 km) from 1979 to 2011 and 12.3 arcmin (~23 km) after 2011 [4]. The more comprehensive CFSR includes GFS as the atmospheric model coupled with land surface, ocean, and sea ice models. The output defines the initial and boundary conditions for the Weather Research and Forecasting (WRF) model [5], which captures orographic effects in regions with massive islands [6]. The merged global and high-resolution regional winds facilitate accurate modeling of multi-scale wave processes from the open ocean to the shore for operational forecasting and long-term hindcasting.