About Casco Bay

Casco Bay is a popular tourist and recreation area. It is also home port to more than 150 fishing vessels and is New England’s third largest fishing port in terms of dollar value. Portland Harbor, in the western section of Casco Bay, is the most important port on the coast of Maine and is a popular cruise ship port of call. This ice-free harbor offers safe anchorage for vessel traffic carrying petroleum, electronics, paper products, and other goods, and is the Atlantic terminus for petroleum product pipeline shipments to Canada (The Port of Portland, Maine : http://www.portofportlandmaine.org).

Background

Circulation in the Casco Bay region is driven primarily by tides. Winds are generally southerly in the summer and northerly in the winter. Occasional “northeasters” can lead to gale force winds. These winds, however, typically are much less severe by the time they reach the coastal area near Portland.

The main channel entrance to Portland Harbor lies between Cushing Island and the mainland. Northwest of Hussey Sound, between Great Diamond Island and Cousins Island, is a naval anchorage and oil transfer area. Near the harbor approaches are numerous shoals.

The Casco Bay region has extensive mudflats, particularly in the areas of the Fore River, the Presumpscot River, Back Cove, Mackworth Island, Little and Great Diamond Islands, Little and Great Chebeague Islands, Cousins and Littlejohn Islands, and Mussel Cove. Mudflats are typically exposed at low tide and submerged at high tide. GNOME does not model currents in these regions; only diffusion and wind move oil across mudflats to shoreline.

The Bath Iron Works (BIW) Dry-Dock is in northeast Portland Harbor and is indicated as a rectangular island on the Location File map. This dry-dock–9 barges lashed together–is due to be removed in 2001. It will be replaced by a cruise ship terminal at a later date. The Casco Bay Location File models currents going around the dry-dock.

Current Patterns

The Casco Bay Location File uses one current pattern to simulate tidal circulation. The tidal current pattern is scaled to tides in the Portland Harbor entrance southwest of Cushing Island (43.63°N, 70.21°W).

The current pattern was created with the NOAA Current Analysis for Trajectory Simulation (CATS) hydrodynamic application.

References

Oceanography

Hulburt, E. M. and N. Corwin, 1970. Relation of the Phytoplankton to Turbulence and Nutrient Renewal in Casco Bay, Maine. Journal Fisheries Research Board of Canada, vol. 27 (11), pp. 2081-2090.

Ridderinkhof, H., 1995. Lagrangian Flows in Complex Eulerian Current Fields. In: Quantitative Skill Assessment for Coastal Ocean Models [Coastal and Estuarine Studies, Vol. 47]. D. R. Lynch and A. M. Davies (eds). Washington, D.C.: American Geophysical Union. pp. 31-48.

Vermersch, J. A., R. C. Beardsley, and W. S. Brown, 1979. Winter Circulation in the Western Gulf of Maine: Part 2: Current and Pressure Observations. Journal of Physical Oceanography, vol. 9, pp. 768-784.

Xue, H., F. Chai, and N. R. Pettigrew, 2000. A Model Study of the Seasonal Circulation in the Gulf of Maine. Journal of Physical Oceanography, vol. 30, pp. 1111-1135.

Wind and Weather Information

National Data Buoy Center, Portland Buoy

Current offshore meteorological conditions at a buoy 12 nautical miles southeast of Portland, ME.

The Weather Underground, Inc. - Current and forecast weather for Portland, Maine

Current and forecast weather for Portland, Maine

The Weather Underground, Inc. - Marine forecast for Eastport, ME to Stonington, ME

Oil Spill Response

NOAA's Emergency Response Division (ERD)

Tools and information for emergency responders and planners, and others concerned about the effects of oil and hazardous chemicals in our waters and along our coasts.