The record maximum of Antarctic sea ice resulted chiefly from anomalous winds that transported cold air masses away from the Antarctic continent, enhancing thermodynamic sea ice production far offshore.
Massonnet, F., Guemas, V., Fuckar, N., & Doblas-Reyes, F. J. (2015). The 2014 High Record of Antarctic Sea Ice Extent. Bulletin of the American Meteorological Society, 96, 163-167. https://doi.org/10.1175/BAMS-D-15-00093.1 (Original work published 2015)