Dynamics of a mesoscale eddy off Cape Ann, Massachusetts in May 2005
Libby, Scott P.
Anderson, Donald M.
MetadataShow full item record
KeywordMesoscale eddy; Headland; Cape Ann; Gulf of Maine; Massachusetts Bay; Merrimack River; Freshwater plume; Sub-mesoscale filaments; Alexandrium fundyense; Harmful algal bloom; Red tide
Observations and numerical modeling indicate that a mesoscale anti-cyclonic eddy formed south of Cape Ann at the northern entrance of Massachusetts Bay (MB) during May 2005, when large river discharges in the western Gulf of Maine and two strong Nor’easters passing through the regions led to an unprecedented toxic Alexandrium fundyense bloom (red tide). Both model results and field measurements suggest that the western Maine coastal current separated from Cape Ann around May 7-8, and the eddy formed on around May 10. The eddy was trapped at the formation location for about a week before detaching from the coastline and moving slowly southward on May 17. Both model results and theoretical analysis suggest that the separation of the coastal current from the coast and subsequent eddy formation were initiated at the subsurface by an adverse pressure gradient between Cape Ann and MB due to the higher sea level set up by onshore Ekman transport and higher density in downstream MB. After the formation, the eddy was maintained by the input of vorticity transported by the coastal current from the north, and local vorticity generation around the cape by the horizontal gradients of wind-driven currents, bottom stress, and water density induced by the Merrimack River plume. Observations and model results indicate that the anti-cyclonic eddy significantly changed the pathway of nutrient and biota transport into the coastal areas and enhanced phytoplankton including Alexandrium abundances around the perimeter of the eddy and in the western coast of MB.
Author Posting. © The Author(s), 2011. This is the author's version of the work. It is posted here by permission of Elsevier B.V. for personal use, not for redistribution. The definitive version was published in Deep Sea Research Part I: Oceanographic Research Papers 58 (2011): 1130-1146, doi:10.1016/j.dsr.2011.08.009.
Showing items related by title, author, creator and subject.
Rainville, Luc; Jayne, Steven R.; Cronin, Meghan F. (American Meteorological Society, 2014-04-15)Mooring measurements from the Kuroshio Extension System Study (June 2004–June 2006) and from the ongoing Kuroshio Extension Observatory (June 2004–present) are combined with float measurements of the Argo network to study ...
Glickson, Deborah A.; Fratantoni, David M.; Wooding, Christine M.; Richardson, Philip L. (Woods Hole Oceanographic Institution, 2000-07)This data report summarzes 45 surface drifter trajectories collected between November 1998 and June 2000 as part of the North Brazil Current (NBC) Rings Experiment. NBC rings have been proposed as one of several important ...
Spall, Michael A.; Thomas, Leif N. (American Meteorological Society, 2016-10-07)Downfront, or downwelling favorable, winds are commonly found over buoyant coastal plumes. It is known that these winds can result in mixing of the plume with the ambient water and that the winds influence the transport, ...