Surface-layer fronts, buoyant gravity currents, and diurnal warm layers: Dynamics and interactions

Montag 23.06.2025, 11:00 → 12:00 Europe/Berlin

5-1.214 - Linke Seite – Großer, unterteilbarer Konferenzraum (GEOMAR - Standort Ostufer / GEOMAR - East Shore)

Speaker: Lars Umlauf, IOW, Warnemünde, Germany

Hybrid  -  online via https://geomar.webex.com/geomar-en/j.php?MTID=mf415834ed76a742bacf01eada863885d

Meeting number: 2787 635 2083
Password: XYwu583sQtA

Abstract
Submesoscale fronts in the ocean surface layer — loosely defined by cross-front scales of 0.1 to 10 kilometers — have recently received considerable attention due to their impact on near-surface energy dissipation, surface-layer restratification, and vertical transport across the mixed-layer base. The instabilities involved in these processes are not well represented in numerical models, and they are notoriously difficult to observe due to their small spatial scales and evanescent nature. Here, some recent work of our group will be presented, focusing especially on aspects of frontal dynamics that are not well understood at the moment. These include the quantification and parameterization of energy dissipation in submesoscale fronts, their late-stage collapse into buoyant gravity currents (similar in many respects to the more well-known buoyant river plumes), and their interaction with diurnal warm layers that evolve daily in the upper few meters especially in the tropical ocean.