Recent oceanographic variability and warming of the continental shelf south of New England and implications for acoustic propagation and sub-bottom characterization

Abstract

The continental shelf south of New England is a complex oceanographic environment for underwater acoustics. The combination of large seasonal changes in stratification, complicated frontal phenomena associated with the shelfbreak front, and small spatial scales of variability for soundspeed results in important effects on acoustic propagation and sub-bottom characterization. Two recent trends have also become important. Longer-term warming, on the decadal scale, is affecting shelf water temperatures and soundspeed profiles. In addition, from April 2014 to December 2015, there was a substantial influence on shelf water mass properties from Gulf Stream warm core rings impinging on the continental shelf. The rings also diverted the shelfbreak front onshore at times as well. Some implications for propagation and sub-bottom characterization will be discussed.