Lagrangian Modeling of Potential Vorticity Homogenization and the Associated Front in the Gulf Stream

Abstract

Abstract This paper studies the water property exchange across the Gulf Stream, the gyre-scale potential vorticity homogenization, and the associated property front closely aligned with the Gulf Stream using a double gyre-jet ocean circulation model, which consists of a subtropical gyre in the south, a subpolar gyre in the north, and a meandering jet between the two gyres. A Lagrangian particle modeling method is used in this study. The role of the Gulf Stream and the annual north-south shift of the wind system and their interplay in these processes are thoroughly examined. The main conclusions are 1) the Gulf Stream could result in large water property exchange between the subtropical and subpolar gyres and the annual meridional shift of the wind pattern could further enhance the property exchange; 2) most of the Lagrangian transport and mixing across the jet core occurs in the interior and the eastern region, whereas most of the Lagrangian exchange in the western basin, especially in the western boundar...