Patterns of wintertime Arctic sea ice leads and their relation to winds and ocean currents

• Main Authors: Willmes, Sascha, Heinemann, Günther, Schnaase, Frank
• Format: Text
• Language: English
• Published: 2023
• Subjects: Arctic; Sea ice
• Online Access: https://doi.org/10.5194/tc-2023-22; https://tc.copernicus.org/preprints/tc-2023-22/

We use a novel sea-ice lead climatology based on satellite observations with 1 km 2 spatial resolution to identify predominant patterns in Arctic wintertime sea-ice leads. The causes for the observed spatial and temporal variabilities are investigated using ocean surface current velocities and eddy kinetic energies from an ocean model (FESOM) and winds from a regional climate model (CCLM) and ERA5 reanalysis, respectively. The presented investigation provides clear evidence for the influence of ocean depth and associated currents on the mechanic weakening of sea ice and the accompanied occurrence of sea-ice leads with their characteristic spatial patterns. While the ocean influence on lead dynamics acts on a rather long-term scale (seasonal to inter-annual), the influence of wind appears to trigger sea-ice lead dynamics on shorter time scales of weeks to months and is largely controlled by individual events causing increased divergence.