In October 2024, Pine Island Glacier, known for its fast-paced retreat and frequent iceberg calving, revealed more than its icy edge. This time, unusual atmospheric activity brought attention to the skies above Antarctica's West Antarctic Ice Sheet. On October 10, the Operational Land Imager (OLI) on NASA's Landsat 8 captured an exceptional image showing “sea smoke” and snow carried by powerful winds.
These phenomena usually evade satellite images because clouds often block the view. However, this day was an exception, providing a rare look at near-surface atmospheric events, explained Christopher Shuman, a glaciologist from the University of Maryland, Baltimore County, based at NASA's Goddard Space Flight Center.
Sea Smoke at the Glacier's Edge
Sea smoke, in particular, emerged prominently near the glacier's terminus and over open water at its northern boundary. This phenomenon arises due to the stark temperature contrast between the icy surface and surrounding waters. Strong winds pushed the sea ice and water away from the glacier, drawing relatively warmer water to the surface. When this warmer water meets the frigid air, it condenses into fine ice crystals, creating the appearance of smoke over the sea.
Winds Stirring Up Blowing Snow
At the same time, intense winds whipped snow from the surrounding ice sheet, adding streams of white across the glacier. This blowing snow was especially visible near a turbulent area south of Pine Island Glacier, known as a shear zone, where the collision of ice masses produces complex formations.
The Impact of Antarctic Spring Winds on Ice Sheets
The strength of these Antarctic winds, particularly during the spring, is not surprising, Shuman noted. These katabatic winds, formed as cold, dense air descends from the high interior to the coast, regularly emerge after months of isolated, chilled air.
In regions like Pine Island, these winds can influence the polar ice sheet's surface mass balance by transporting and sublimating snow. While the impact of blowing snow on ice loss remains uncertain, its influence is significant, and capturing these events offers insight into the changing dynamics of Antarctic ice sheets.
