This article has been reviewed according to Science X's editorial process and policies. Editors have highlighted the following attributes while ensuring the content's credibility: Polynyas are one of Antarctica's great counterintuitive features: recurring areas of open water surrounded by vast expanses of sea ice. These unusual environments are hot spots for sea-ice production, ocean–atmosphere exchange and biological productivity.
They are commonly maintained by powerful winds that push newly formed ice away from the coast, repeatedly exposing the ocean to the freezing Antarctic atmosphere. Yet these strong winds do something else: they generate waves. This is hardly surprising.
Wind blowing across open water generates waves, and coastal polynyas are no exception. However, despite this seemingly obvious connection, we have rarely considered how these waves might affect the surrounding sea ice. Our study published in Nature Communications shows that during extreme wind events, waves generated inside the Vincennes Bay Polynya in East Antarctica can become steep enough to fracture the surrounding sea ice from the inside out, triggering a series of feedback processes that alter the evolution of the polynya itself.
Our original research had little to do with waves generated inside coastal polynyas. We were interested in how energetic waves originating from the Southern Ocean propagate through hundreds of kilometers of Antarctic sea ice, and deployed wave-measuring buoys on coastal landfast ice in East Antarctica to investigate this process. During several of our deployments, however, the ice carrying our instruments broke away from the coast, leaving the buoys drifting across the nearby Vincennes Bay Polynya.
Each time this happened, we noticed a similar pattern in the measurements: wave heights increased considerably as the buoys moved into open water. Initially, these observations were incidental to our original research. But as the pattern repeated over several years, we began to appreciate how energetic waves generated within the polynya could become.
This raised a question we had not originally set out to investigate: could these waves be large enough to break up the surrounding sea ice and influence the evolution of the polynya itself? When waves encounter a sea-ice cover, they cause the ice to bend as they propagate through it. If the resulting stresses become sufficiently large, the ice can fracture.
Extract — continue reading at the source.
