An investigation of the link between lead-induced thermohaline convection and arctic eddies

• Main Authors: John W. M. Bush, Andrew W. Woods
• Other Authors: The Pennsylvania State University CiteSeerX Archives
• Format: Text
• Language: English
• Subjects: Arctic
• Online Access: http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.514.7719; http://www-math.mit.edu/~bush/Link-induced_thermohaline_circulation.pdf

A recent laboratory study indicates that a turbulent buoyant line plume discharging into a rotating strati-fied fluid provides a natural mechanism for generating a series of anticyclonic geostrophic vortices [Bush and Woods 1999]. Here we examine the implications of these experimental results in the context of the thermohaline convection which develops when saline water is released as leads freeze over in the polar oceans. Using the exper-imental results in conjunction with a simple numerical model of plume dynamics in a non-uniformly stratified environment, we develop a model which characterizes the geometry of the eddies which would develop owing to lead-induced convection. The model predicts that, in the absence of strong currents, lead-induced thermoha-line convection may generate anticyclonic geostrophic vortices of characteristic radius 2-10 km at the base of the mixed layer; however, this mechanism cannot account for the arctic eddies observed at substantial depths beneath the mixed layer, cyclonic, or strongly ageostrophic eddies.