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: Samuel Brenner, Christopher Horvat, Paul Hall, Anna Lo Piccolo, Baylor Fox‐Kemper, Stéphane Labbé, Véronique Dansereau
• Format: Article in Journal/Newspaper
• Language: English
• Published: Wiley 2023
• Subjects: Geophysics. Cosmic physics; QC801-809; Sea ice
• Online Access: https://doi.org/10.1029/2023GL105703; https://doaj.org/article/10adc70a3a7447ba9c041bf210928b96

Abstract 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.