Analyzing vertical ocean transport with Lagrangian coherent structures

Michael Allshouse

NORTHEASTERN UNIVERSITY

Because the horizontal velocities are often an order of magnitude greater than vertical mixing, it can be difficult to quantify the vertical transport of material exclusively from Eulerian methods, so we propose the use of Lagrangian coherent structure analysis to provide a reduced order illustration of the pathways for transport from the surface to depth. The goal of this proposal is to develop a real-time method for identifying attracting coherent structures at the surface of the ocean that signal potential downwelling events occurring in the underlying water column. This requires the correlation of two-dimensional surface coherent structures to vertical transport below. We propose the use of classification of hyperbolic structures near the edges of materially coherent vortices as a signal of nearby vertical transport. Testing of this method on numerical ocean models will reveal the potential of these structures for predicting future vertical transport. A secondary objective of this proposal is to develop a drifter deployment optimization that best demonstrates both the horizontal and vertical transport near the density front.

You can access the relevant Webpage for CALYPSO here.

You can access the relevant Webpage for the CALYPSO 2019 experiment here.