Stationary Rossby Waves in Southern Ocean

Abstract

This poster explains the role of stationary oceanic Rossby waves (SRWs) in carbon uptake in the Southern Ocean. The Southern Ocean accounts for nearly 40% of global oceanic anthropogenic carbon uptake per year, yet the mechanisms transporting carbon to the interior ocean remain not well known. Planetary Rossby waves are large-scale waves driven by conservation of potential vorticity as fluid moves across latitudes, shaped by the planet’s rotation and varying Coriolis effect. SRWs are generated by interactions between the Antarctic Circumpolar Current (ACC) and topography. Because the ACC continuously flows over the same topographic features, the Rossby wave response is constantly reinforced, making them stationary. Presenting recent findings, we highlight how SRW-induced processes dominate small-scale vertical transport. This can account for a significant portion of total carbon uptake. These insights show the need for high-resolution models to accurately capture SRW dynamics and their impact on carbon capture.

screenshot of the poster entitled Stationary Rossby Waves in Southern Ocean

Poster number:

G339.3

GEOF339 - Spring 2025

Upwelling along the southern West African Coast – Causes and Effects

Abstract

This poster looks at the effect of winds on the circulation of oceans with a boundary. It explains upwelling systems with a focus on the Benguela upwelling system in southern Africa. The winds in this area move surface water away from the coast and this causes deeper water to rise. This water is cold and nutrient rich and can be measured using satellites, which can detect the cold sea surface temperatures and nutrients through increased chlorophyll concentrations. This increased biological activity is a major economical factor for surrounding countries. The poster also describes further effects of this upwelling system on the ocean, biological activity and the atmosphere.

screenshot of the poster entitled Upwelling along the southern West African Coast - Causes and Effects

Poster number:

G339.2

Authors:

Angela Muhmenthaler

GEOF339 - Spring 2025

Shutdown of the great water conveyor belt? – Possible future changes in the Atlantic Meridional Overturning Circulation

Abstract

The Atlantic Meridional Overturning Circulation (AMOC) is a large-scale ocean circulation in the Atlantic. It brings warm and salty surface water from the tropics northward, where it becomes cold and dense, and then sinks. The cold deep water is then transported back toward the tropics.
The current can be measured using moorings, and with a mooring array, the volume transport can be calculated. In models, a weakened AMOC can be simulated by adding freshwater to the North Atlantic. Comparing models with and without a reduced AMOC can be used to study potential consequences if the AMOC becomes weakened. The AMOC transports heat from the equator to higher latitudes, keeping Europe warmer than it otherwise would be. Global warming could weaken the AMOC and affect the climate in Europe and worldwide.

screenshot of the poster entitled Shutdown of the great water conveyor belt? – Possible future changes in the Atlantic Meridional Overturning Circulation

Poster number:

G339.1

Authors:

Reidar Lier
& Julia Steckling

GEOF339 - Spring 2025