The Weddell Gyre, located east of the Antarctic Peninsula, is one of the largest features of the ocean circulation of the Southern Hemisphere. It is adjacent to an important site of bottom water formation, a process that sequesters carbon and heat from the atmosphere and sets the density of the deep ocean, therefore making the region important for global climate.

However, extensive sea ice cover throughout the year has historically prevented continuous observations. Several unique features of the gyre, such as open boundaries and intense surface buoyancy fluxes, make the identification of its forcing mechanisms difficult. A deeper understanding of the dynamics in this remote region will shed light on the role of the gyre in our present climate and help us understand its potential evolution with climate change.

This study uses a high-resolution numerical model which shows that the Weddell Gyre undergoes large seasonal and inter-annual changes. It was found that the gyre speeds up during winter and slows down during summer, and that strong/weak events in the model simulation are correlated with the strength of the regional easterly winds close to the Antarctic continent. These strong/weak events affect sea ice cover, water mass characteristics and bottom water production.

  • Paper: Neme, J., England, M.H., Hogg, A.McC., 2021. Seasonal and Interannual Variability of the Weddell Gyre From a High-Resolution Global Ocean-Sea Ice Simulation During 1958–2018. Journal of Geophysical Research: Oceans 126, e2021JC017662.