Predominant Sea Ice Fracture Zones Around Antarctica and Their Relation to Bathymetric Features

Abstract

Sea ice is of substantial importance for the Southern Ocean, as it insulates the relatively warm ocean from the cold atmosphere. Due to mechanical stress induced by wind and ocean currents, sea ice leads occur, which are characterized by open water and thin ice causing an increase of energy and moisture fluxes between ocean and atmosphere. Furthermore, they contribute to the ice production and provide a habitat for animals. Thus, it is important to gain information about the temporal and spatial distribution of leads on a circum-Antarctic scale. So far, no operational data set exists, which provides such information. We use thermal satellite imagery from the Moderate Resolution Imaging Spectroradiometer to derive the predominant lead patterns for 2003–2018, April–September. This study provides first results for the long-term average lead frequencies in the Southern Ocean and discusses possible links to ocean currents, tides, and the bathymetry.