Ekman transport and its role in polynya formation
The mystery behind the giant hole in the Antarctic sea ice that formed during the winters of 2016 and 2017 has been solved. A group of international researchers has discovered that the complex interactions between wind, ocean currents and the unique geography of the ocean floor, together with the so-called ‘Ekman transport’, are responsible for this phenomenal formation.
Polynyas, which are open areas of water surrounded by sea ice, are created due to the transfer of enormous amounts of heat and carbon between the ocean and the atmosphere. These formations can have a significant impact on the climate of the region and, potentially, globally, as they affect ocean circulation. Therefore, understanding the factors that trigger them is crucial to improve climate models and understand their effects on the climate.
The discovery of the Maud Rise polynya
The study focused on the polynya called Maud Rise, located in the Weddell Sea. For decades, this huge opening in the sea ice had baffled scientists. However, the researchers discovered that this polynya functions as a kind of window through the sea ice, allowing the transfer of heat and carbon between the ocean and the atmosphere during the winter.
The team observed that the flow of the Weddell Sea Current around Maud Rise generated turbulent eddies that transported salt to the surface. This was due to the phenomenon of Ekman transport, which involves water moving at a 90-degree angle to the direction of the wind. This process helped maintain the salt balance necessary for the persistence of the polynya.
The impact of polynyas on the climate
Polynyas not only have a local effect on the climate of the Antarctic region, but can also affect water movement and ocean currents globally. These areas of heat and carbon transfer can modify ocean circulation and spread throughout the ocean, affecting long-term climate.
The discovery of the mechanisms behind the formation and persistence of polynyas in Antarctica is an important advance in our understanding of climate change and its impact on the oceans and atmosphere. This study provides a more complete view of the processes involved in these formations and highlights the importance of considering Ekman transport in climate models.
Article reference: [link to original article](https://www.science.org/doi/10.1126/sciadv.adj0777)
