Sea ice controls stability of Antarctic ice sheet, new study finds

Although ice melted rapidly in many parts of Antarctica during the second half of the 20th century, researchers found that the floating ice shelves surrounding the eastern Antarctic Peninsula have been advancing consistently over the past 20 yea.

Ice shelves — the floes attached to land ice sheets — play a vital role in supporting the uncontrolled release of inland ice into the oce.

Right now, the jury is still out on how sea ice around Antarctica will evolve in response to climate change and thus affect sea level rise, with some models predicting a massive loss of sea ice in the Southern Ocean, while others predict an increa.

Now, an international team of researchers from the Universities of Cambridge and Newcastle in the UK and the University of Canterbury in New Zealand have combined historical satellite measurements, as well as ocean and atmospheric records, to get the most detailed view of how the 1,400-kilometer-long eastern Antarctic Peninsula's ice conditions are changing .

They found that 85 percent of ice shelf circumferences in this part of Antarctica have increased since the early 2000s, after a dramatic reduction in the previous 20 yea.

The findings, published in the journal Nature Geoscience, suggest that sea ice plays an important role in stabilizing ice shelves, just as ice shelves themselves stabilize and support ice shee.

Dr Fraser Christie, lead author of the paper and from the Scott Polar Research Institute (SPRI) at the University of Cambridge, said: "We found that sea ice changes can both prevent and trigger iceberg disintegration on large ice shelves in Antarcti.

In 2019, Christie and his co-authors participated in a spri-led expedition to study ice conditions in the Weddell Sea off the east coast of the Antarctic Peninsu.

"During the expedition, we noticed that parts of the ice shelf coastline were at their most advanced position since satellite records began in the early 1960s," said expedition lead scientist and study co-author Professor Julian Doddswell, who also from SP.

Following this expedition, the team used satellite imagery from 60 years ago, as well as state-of-the-art ocean and atmospheric models, to investigate in detail the spatial and temporal patterns of ice shelf chan.

So what is causing the ice shelves to advance? In the absence of atmospheric and ocean warming over the past 20 years, the main controlling factor is changes in wind patterns in the Weddell Sea region, which push sea ice against ice shelv.

By contrast, wind conditions in the same region between 1985 and 2002 kept sea ice away from the coa.

In almost all cases throughout the satellite era, the disintegration of the eastern Antarctic Peninsula ice shelf occurred only during or shortly after sea ice disappeared in some fo.

However, this period of ice advancement may come to an e.

article title

Antarctic ice-shelf advance driven by anomalous atmospheric and sea-ice circulation