Recent research by University of Utah mathematicians and climate scientists is shedding light on the complex nature of polar sea ice, which is constantly changing due to factors such as changing seasons and rapid climate change. The study focused on two critical processes in the sea ice system: heat flux through sea ice and the dynamics of the marginal ice zone (MIZ), which is a region that separates pack ice from open ocean. Through modeling and field research in both the Arctic and Antarctic, researchers are gaining new insights into how these processes impact global climate.
One of the studies looked at the macrostructures of sea ice in the Arctic, while another focused on the microscale aspects of sea ice in the Antarctic. Both studies found that sea ice is not solid, but rather like a sponge with tiny holes filled with brine. When ocean water interacts with the ice, it can set up a flow that allows heat to move more quickly through the ice. This has implications for how heat is transferred between the ocean and atmosphere and how fast sea ice melts, which in turn affects global climate patterns.
The thermal conductivity study found that new ice, as opposed to old ice that remains frozen year after year, allows for more water flow and greater heat transfer. Current climate models may be underestimating the amount of heat moving through sea ice because they do not fully account for this water flow. By improving these models, scientists can better predict sea ice melting rates and their impact on the global climate.
The studies also found that the MIZ has been widening by 40% over the past several decades and shifting towards the pole as sea ice pack sizes decline. This increase in the MIZ has consequences for how heat flows between the ocean and atmosphere, as well as for the ecosystem in the Arctic, from microorganisms to polar bears. Changes in the MIZ have global implications, as they affect climate patterns and weather systems around the world.
The research proposed a new model for understanding the MIZ as a large-scale phase transition region, similar to how ice melts into water. By simplifying the complex interactions in the MIZ, researchers hope to gain insights into how the system works and why it is changing. The focus is on understanding the seasonal cycles of the MIZ and applying this model to better predict trends observed over the past few decades.
Overall, the studies highlight the importance of understanding the dynamic nature of polar sea ice and how it impacts global climate. By developing new models and insights into the processes that govern sea ice dynamics, researchers hope to improve predictions of sea ice trends and their implications for the planet. The findings emphasize the interconnectedness of the Earth’s climate system and the need for continued research to address the challenges posed by a changing climate.