Dutch researchers say climate change is expanding Antarctica's sea ice.
Their peer-reviewed study is published in the journal Nature Geoscience.
The paradoxical phenomenon is thought to be caused by relatively cold plumes of fresh water derived from melting beneath the Antarctic ice shelves, the BBC reports.
This melt water has a relatively low density, so it accumulates in the top layer of the ocean.
The cool surface waters then re-freeze more easily during autumn and winter.
The team from the Royal Netherlands Meteorological Institute says this explains the observed peak in sea ice during these seasons.