John Marshall

Cecil and Ida Green Professor of Oceanography, MIT

Ventilation and thermocline theory

Fluid parcels, which are exposed to surface processes in the upper boundary (mixed) layer of the ocean, are carried into the stratified interior in a process known as ‘subduction’, a process that controls the vertical structure of the thermocline and the rate at which the ocean ingests tracers, such as CO2 and tritium, from its surface layers into its interior. My work has contributed to the understanding of oceanic subduction and helped place it on a firm theoretical footing [15], [17], [26] & [49]. These theoretical ideas were applied to estimate, for the first time, the annual-mean rate at which fluid is subducted into the thermocline from observations of hydrography and thermodynamic transfer with the atmosphere [22] and [29].

Papers [4], [6], [8], [9] contributed to theories of the inertial recirculation of subtropical gyres and [14] & [15] to the interaction of mixed layers with the stratified thermocline below.