Key branches of the global oceanic overturning can be located and monitored with an observing system based on satellite altimetry and in situ observations, particularly hydrography, floats and drifters. The elusive arteries of meridional overturning circulation (MOC) at high latitude strongly affect global heat balance, yet they cannot fully and accurately be represented in numerical climate models. These pathways are the focus of this research. Satellite altimetric measurements have matured to the point where decadal variability is clear and longer term trends are beginning to be established. At the same time our robotic Seagliders patrolling the subpolar Atlantic (Eriksen & Rhines, 2007), ARGO floats and surface drifters are providing much sharper 3-dimensional space-time coverage of the MOC. Extending our earlier research on the deceleration and shrinking of the subpolar gyre of the North Atlantic, we now address the transition between the subtropics and the subpolar regions where deep sinking of the MOC occurs. Using a jet-finding technique we will collaborate with Rintoul and Sokolov of CSIRO, Australia in comparing MOC pathways in the Southern Ocean and the high northern latitudes of the Atlantic and Pacific.
Pathways of Meridional Circulation in the Ocean Climate System