New tools and ideas for ocean water mass analyses

– Rémi Tailleux, Associate Professor in Physical Oceanography –

Résumé :

The main aim of my talk will be to clarify the dynamical basis for isopycnal analyses of ocean water masses. In particular, I will try to answer or clarify the following questions: how should we define isopycnal surfaces in the oceans? What is the physical basis for isopycnal analysis? Are neutral surfaces really the superior choice? What are the physical processes responsible for the impossibility of constructing exactly neutral surfaces?  Surprisingly, I will show that addressing these questions is related to addressing other equally important questions in ocean circulation theory, such as: what is heat in the oceans? How should we define and quantify the mechanical energy input by surface buoyancy fluxes in the oceans? In my talk, I will argue that the key to addressing these questions lies in the theory of available potential energy, which I will justify in a new way. I will also discuss how these new ideas can be used to: 1) construct improved density surfaces with a rigorous physical basis; 2) develop a new physically-based spice/heave decomposition of ocean temperature anomalies for studying the physics of ocean heat uptake; 3) develop fast and efficient ways to compute Lorenz state of minimum potential energy and isopycnal mean values of arbitrary tracers. 4) Provide a complete energy analysis of the EN4 dataset.

Among other things…