VIMS Dead Zone Forecasts

An experimental forecast from the Virginia Institute of Marine Science (VIMS) could help Chesapeake Bay fishermen avoid “dead zones.”

Predicting the general outline and seasonality of dead zones is fairly straightforward. An area of oxygen-poor water typically occupies the deeper parts of the Bay’s main channel during the summer doldrums, when hot weather drives gases from the water and encourages algal growth, while calm winds minimize the waves and currents that would otherwise help mix relatively oxygen-rich surface waters into the depths.

But predicting day-to-day changes in the size and shape of the Bay’s dead zone is more of a challenge. Professor Marjy Friedrichs is collaborating on the dead-zone model and forecasts with researchers at VIMS and from around the region.

Colleagues include fellow VIMS researchers Dr. Carl Friedrichs and Dr. David Forrest, Dr. Raleigh Hood of the University of Maryland Center for Environmental Science (UMCES) and Dr. Malcolm Scully of the Woods Hole Oceanographic Institution.

The researchers’ ultimate plan is to incorporate their real-time forecasts into more comprehensive monitoring and prediction products such as NOAA’s Chesapeake Bay Interpretive Buoy System (CBIBS) and the Mid-Atlantic Regional Association Coastal Ocean Observing System (MARACOOS).

VIMS’ real-time daily forecasts of Bay dead zones are enabled by use of a computer model that simplifies the Bay’s complex biology while still accurately simulating the Bay’s physical dynamics.

The model complements the seasonal predictions of Bay oxygen developed by NOAA-sponsored researchers at UMCES and the University of Michigan, as well as the more comprehensive water-quality models used by NOAA, the Environmental Protection Agency, and other agencies to track the restoration of Bay health.

“Our model is much simpler than the complex models used to predict overall water quality in the Bay,” says Marjy Friedrichs, “but it predicts dead-zone dynamics just about as well.”

source: Virginia Institute of Marine Science