Speaker

Christopher Horvat, Ph.D., Assistant Professor, Brown University

The Polar Tempest: ocean mixing and remote sensing at the sea ice floe scale

Abstract

Recent dramatic changes in both Arctic and Antarctic sea ice have profound consequences for the global climate system, yet modern climate models have long struggled to predict them. Here I will discuss recent efforts to understand mixing processes generated at the scale of sea ice floes in response to brittle sea ice deformation. These suggest that a key reason for the lack of model skill is sea ice geometric variability. I’ll show that contemporary parameterizations of ocean vertical mixing underestimate ocean mixing in the Arctic and Southern Ocean. This is coupled with biased overestimations of sea ice coverage in standard sea ice remote sensing products, and reinforces the view of polar oceans being quiescent and simple. Instead, evidence points to active, floe-scale mixing processes, which may be explored using a new generation of parameterizations, sea ice models, and remote sensing products under development both in my group and in others.