Predicting Currents in the Straits of Mackinac

The Straits of Mackinac is the connecting waterway between Lakes Michigan and Huron of the Great Lakes. The surface and sub-surface currents in the straits are strong and complex—they change direction of flow regularly. Overall, water flows from Lake Michigan to Lake Huron, but this occurs with a lot of variability depending on the season. During the summer, for example, the currents are bidirectional.

The currents change direction roughly every 1.5 days.
Click animation to enlarge
Surface and deeper water flow in opposite directions during the summer. Click animation to enlarge

Implications for the movement of contaminants in the Straits

GLERL scientists have developed a 3D computer model that simulates currents in the Straits of Mackinac. They have been able to show that the unique flows in the Straits would cause materials in the water to disperse far more quickly than in other locations in the Great Lakes. The graphic below is an example of how dispersion in the Straits of Mackinac would differ from other areas, such as in Lake Michigan and the western basin of Lake Erie.



Reference

More Information

Fact Sheet: Predicting Currents in the Straits of Mackinac with the Great Lakes Coastal Forecasting System

Anderson & Schwab 2017: Meteorological influence on summertime baroclinic exchange in the Straits of Mackinac
Anderson & Schwab 2013: Predicting the oscillating bi-directional exchange flow in the Straits of Mackinac
Saylor & Miller 1991: Current flow through the Straits of Mackinac
Saylor & Sloss 1976: Water Volume Transport and Oscillatory Current Flow through the Straits of Mackinac

Real-Time Buoy Data from the Straits

Contact:

Eric Anderson
734-741-2293