How Openings in Antarctic Sea Ice Affect Worldwide Climate

We've already learned from class that water plays a huge role in temperature regulation for the earth. Because of its properties associated with hydrogen bonding, ice is able to float to the surface of water allowing for life underneath, and it is able to regulate temperature because the bonding does not allow water to respond to temperature changes very quickly. This study was able to highlight just how important water and ice in our oceans can be when it comes to climate change, especially in the Southern Ocean.

Until recently, experts in oceanography and climate scientists thought that the major contributing factor to ocean and atmospheric conditions was found in the tropics. However, this team composed of researchers from the University of Pennsylvania, Spain’s Institute of Marine Sciences and Johns Hopkins University was able to see significant findings dealing with the sea ice in the Weddell Sea, which is instead located in the South. 

What they were researching was an observed pocket or hole called a polyna in the normally solid ice structure in the sea. Polynas occur when the warm sub-surface waters mix at a location with cold waters surface present. This leads to the process of open-ocean convection, which means that the heat ends up rising and the cooler temperatures of water drop. The heat ends up melting a hole in the otherwise solid ice. 

The team was able to make models to show how these holes in the ice of the Weddell sea actually impacted the climate. To quote one of the researchers, Irina Marinov, these were some of the findings: “This small, isolated opening in the sea ice in the Southern Ocean can have significant, large-scale climate implications. Climate models suggest that, in years and decades with a large polynya, the entire atmosphere warms globally, and we see changes in the winds in the Southern Hemisphere and a southward shift in the equatorial rain belt. This is attributable to the polynya.”

In addition to these findings, their model also showed that polynas show up around every 75 years. When they do, they release the ocean's heat - which doesn't just end up affecting the local area, it also increases temperatures in the sea-surface and atmosphere of the entire Southern Hemisphere. It also has a smaller impact on the Northern Hemisphere. In essence, the polyna ends up playing a major role in precipitation that leads to agriculture in populated areas and worldwide temperatures. 

The article ends by pointing out that with climate change, these polynas may not be showing up as frequently. Without having a "release valve" for the ocean's temperature that shows up in a predicable timeframe, we don't know how bad the impacts will be. Because it became clear that these pockets lead to a number of environmental changes, I believe that we need to pour more research into the topic and find out how big of an impact we're looking at, and if we can reverse it in any way if it ends up being detrimental to our climate.

-Gabrielle Whiffen

Reference: https://news.upenn.edu/news/penn-how-openings-antarctic-sea-ice-affect-worldwide-climate