Scale-Dependent Air-Sea Exchange in the Polar Oceans: Floe-Floe and Floe-Flow Coupling in the Generation of Ice-Ocean Boundary Layer Turbulence

• Published in: Geophysical Research Letters
• Main Authors: Brenner, Samuel, Horvat, Christopher, Hall, Paul, Lo Piccolo, Anna, Fox-Kemper, Baylor, Labbé, Stéphane, Dansereau, Véronique
• Other Authors: Université Paris Cité (UPCité), Institut des Sciences de la Terre (ISTerre), Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Savoie Mont Blanc (USMB Université de Savoie Université de Chambéry )-Centre National de la Recherche Scientifique (CNRS)-Université Gustave Eiffel-Université Grenoble Alpes (UGA)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2023
• Subjects: [SDU]Sciences of the Universe [physics]; Sea ice
• Online Access: https://insu.hal.science/insu-04604353; https://insu.hal.science/insu-04604353/document; https://insu.hal.science/insu-04604353/file/Geophysical%20Research%20Letters%20-%202023%20-%20Brenner%20-%20Scale%E2%80%90Dependent%20Air%E2%80%90Sea%20Exchange%20in%20the%20Polar%20Oceans%20Floe%E2%80%90Floe%20and.pdf; https://doi.org/10.1029/2023GL105703

International audience Sea ice is a heterogeneous, evolving mosaic of individual floes, varying in spatial scales from meters to tens of kilometers. Both the internal dynamics of the floe mosaic (floe-floe interactions), and the evolution of floes under ocean and atmospheric forcing (floe-flow interactions), determine the exchange of heat, momentum, and tracers between the lower atmosphere and upper ocean. Climate models do not represent either of these highly variable interactions. We use a novel, high-resolution, discrete element modeling framework to examine ice-ocean boundary layer (IOBL) turbulence within a domain approximately the size of a climate model grid. We show floe-scale effects could cause a marked increase in the production of fine-scale three-dimensional turbulence in the IOBL relative to continuum model approaches, and provide a method of representing that turbulence using bulk parameters related to the spatial variance of the ice and ocean: the floe size distribution and the ocean kinetic energy spectrum.