Why sea ice cover around Antarctica is rising
A new NASA-led study has found why the sea ice cover surrounding Antarctica has been increasing slightly, in sharp contrast to the drastic loss of sea ice occurring in the Arctic Ocean. According to the study, the geology of Antarctica and the Southern Ocean is responsible for this rise.
- According to the study, two persistent geological factors — the topography of Antarctica and the depth of the ocean surrounding it — are influencing winds and ocean currents, respectively, to drive the formation and evolution of Antarctica’s sea ice cover and help sustain it.
- The study notes that as sea ice forms and builds up early in the sea ice growth season, it gets pushed offshore and northward by winds, forming a protective shield of older, thicker ice that circulates around the continent.
- The persistent winds, which flow down slope off the continent and are shaped by Antarctica’s topography, pile ice up against the massive ice shield, enhancing its thickness.
- This band of ice, which varies in width from roughly 100 to 1,000 km, encapsulates and protects younger, thinner ice in the ice pack behind it from being reduced by winds and waves.
- As the sea ice cover expands and ice drifts away from the continent, areas of open water form behind it on the sea surface, creating “ice factories” conducive to rapid sea ice growth.
