Prince William Sound Field Experiment

why care about ocean forecasting?

Knowing the strength of the currents on any given day via ROMS may become as easy as knowing whether or not it might rain that day. ROMS will be able to accurately forecast surface currents, tides, and temperatures, as well as track waterborne nutrients or pollutants.

Ocean forecasting
in the sound

roms model image

Above: output from the ROMSmodel for the Pacific Ocean, 1993-2004. Colors represent ocean temperatures.

See an animation of how Pacific Ocean currents changed from 1993-2004.


Forecasts: Ocean

principal investigator:
Yi chao, NASA Jet Propulsion Laboratory

Just as meteorologists forecast the behavior of the atmosphere, scientists are using the information gathered from the Prince William Sound Observing System to predict the behavior of the ocean waters of the Sound and the waters that flow through it.

ROMS: Understanding Ocean Dynamics
in the Sound

Ocean circulation in Prince William Sound is driven by an intricate mixture of buoyancy, wind, tidal, and remote forcing. A research team led by Dr. Yi Chao from the Jet Propulsion Lab and including Dr. Xavier Capet from UCLA has developed a Regional Ocean Modeling System (ROMS) for the Sound that can simulate the behavior of currents, tides, salinity, and temperatures at any time during the year.

Zooming In

The group has created three scales of measurement, with the largest measuring the Gulf of Alaska, and the smallest focused on the Sound. As the area of measurement decreases, the resolution increases to as little as 1.2 square km. Why the different scales? "If we want to model what is going on inside the Sound properly, we need to know what is going on outside the Sound," Capet said.

regional ocean modeling system in the soundDiscoveries
to Date

Preliminary studies that have been done in the Sound support other scientists' theories of a stable counter-clockwise gyre that is particularly strong in the summer. It also clearly shows the movement of a warmer current from the south as is passes along the coast in the winter.

Most importantly, what the model shows is that conditions in the Sound vary greatly from one location to another, and also vary greatly from one time to another.

Above: ROMS ocean temperatures in the Sound.

What’s Next

After validating the model, the team will quantify water exchanges between the open ocean and the Sound, including residence time in the Sound and mean fluxes through Hinchinbrook entrance. The preliminary ROMSimplementation for the Sound, Cook Inlet, and the nearby Gulf of Alaska coastal oceans shows very encouraging results when compared to observational data from moorings and drifters.