New research shows a link between the size of ocean waves and sea ice extent in the Antarctic. Larger waves may be causing stress to the ice and allowing it to fracture.
Due to the up and down motions of the waves passing through sea ice, scientists are led to believe that the size of waves has a greater effect on both the expansion and recession of the sea ice edge in the southern ocean than previously thought.
According to a report in Nature Magazine, researchers from New Zealand’s National Institute of Water and Atmospheric Research discovered that ocean waves over three meters in height have a negative impact on polar sea ice by decreasing the fetch, or distance from the shore, to the ice edge.
Just like it’s tougher for you to walk through a muddy swamp, some mediums, such as ice are more difficult for waves to travel through than others. What researchers have recently discovered is the ability for large, storm-induced ocean waves to travel through sea ice for hundreds of kilometers before their oscillations become infrequent. After taking observations at several different locations in Antarctica, New Zealand researchers have concluded that the energy from the up and down motions of the waves cause stress to the ice and fracture it, allowing the ice to break. What this does is alter ice extent, influencing the increased breaking-up and melting of the sea ice. But it’s all about the wave height. Waves with smaller heights are likely to expand the ice edge, while waves with larger heights are more likely to disrupt it. The larger the wave, the farther it will travel and the more stress it will cause the ice. Climate models have not been showing this ice trend, as they do not take wave height greatly into account.
Research near the northern pole was attempted, but because the Arctic is mainly surrounded by land, there was not enough sufficient data to make any conclusions. The Antarctic is almost completely surrounded by water, allowing for better conditions for this study.