People in Coastal Oceanic Numerical Group employ a suite of numerical models to tackle oceanic problems. Regional Ocean Modeling System (ROMS) is used to develop coupled oceanic-biogeochemical models for coastal and shelf oceans. Simulating Waves Nearshore (SWAN) model and Community Sediment Transport Modeling System (CSTMS) are developed for investigating wave and sediment dynamics, and their interaction with the oceanic model.
We take dual approach to ocean modeling. On the one hand, we conduct process-oriented studies to explore fundamental oceanic processes such as mixing in river plumes and circulation dynamics. On the other hand, we develop predictive models for forecasting coastal-ocean response to meteorological and climatic forcing.
Green Tide Forecast
Green tide is detected and defined using the MODIS ocean color satellite images (from Lianbo Hu@OUC), and bloom transport is then predicted using hydrodynamic modeling with passive particle transport. The hydrodynamic model used here is our East China Sea model developed based on the Regional Ocean Modeling System (ROMS). It is driven by GFS atmospheric forecast at surface and global HYCOM oceanic forecast at the open boundary. The prediction of the hydrodynamic model is then used to force a Lagrangian passive transport model to predict the pathway of green tide. Since HYCOM only offers 5-days prediction, rather than 16-days as the GFS weather forecast, our forecast system gives two kinds of predictions: a 5-day accurate short-term predication and a 16-day general medium-term predication. The 5th-day HYCOM data is kept for the medium-term prediction.
The monitoring and forecasting system is updated everyday. The initial position of the green tide is updated whenever a clear satellite image are available, but usually longer than one day due to the frequent cloud coverage.
An operational real ocean forecasting system of the East China Sea is also maintained in POL. The model is run once a day, completing at about 1400Z. Each run starts with a 24 hour assimiliation hindcast and produces ocean forecast every 2 hours from the 0000Z nowcast out to 120 hours. Model output is posted on the Thredds data server and images are provided online
A high resolution hindcast model has been run for the years 2004-2013. We have configured ROMS for a model domain that includes the Changjiang River estuary, the East China and YellowSeas, and a part of continental shelf break opening up to the North Pacific Ocean. An orthogonal curvilinear coordinate system is designed to follow the East China coastline. The grid spacing is 3–4 km over the inner shelf region but increases gradually to 10 km over the open shelf. Model output is posted on a Thredds server and movies can be found online.