- Introduction
- Forecasts
- Output Diagnostics
- Forecast Transects
- Forecast Trajectories
- Waikiki Current Predictions
Regional Ocean Modeling System (ROMS)
The PacIOOS ocean modeling component uses the open source, community-supported Regional Ocean Modeling System (ROMS). ROMS is a free-surface, hydrostatic, primitive equation model discretized with a terrain-following vertical coordinate system. It is coded in parallel for multi-threaded and multi-process architectures and has been widely applied in many applications from planetary scales down to the scales of estuarine environments. Forecasts include predictions of water temperature, ocean currents, salinity, and sea surface height.
Model Boundaries
Boundaries of the three different ROMS model regions outlined in yellow; inset image provides a close-up over Oahu.
Google Earth KMZ file of the above ROMS model boundaries.
Hawaiian Islands Regional Model
This model covers the entirety of the Hawaiian Islands (neglecting the Northwestern Hawaiian Islands preserve) at a horizontal resolution of 4 kilometers, with 30 terrain-following vertical levels. Boundary conditions are provided by the 1/8° Navy Coastal Ocean Model (NCOM). Every day, all available observations collected for the past three days are assimilated (PacIOOS ocean gliders, Argo floats, high-frequency radio (HFR), satellite data, etc.) to provide a "nowcast" for the current ocean conditions. From this nowcast, an ensemble of 7-day forecasts is generated to provide the best ocean circulation estimate with uncertainty for the next week.
Oahu Regional Model
This model covers the ocean south and west of the island of Oahu at varying resolution from 2 kilometers to 700 meters in the horizontal. It is nested within the larger Hawaiian Islands Regional Model, and the same data are assimilated again to resolve finer-scale features (e.g., Penguin Bank). Daily nowcasts and 7-day forecasts are generated.
Oahu South Shore Regional Model
This model covers Māmala Bay with a focus on the beaches at Waikīkī. It is of fine-scale down to 60 meters resolution at the coast. Because of the short-scale dynamics, forecasts are only produced for up to 3 days. This model allows us to examine the outflow during rain events and the conditions along Hawaii's most populous beaches.