Romina Piunno’s Visit to the Geophysical Institute at the University of Bergen

As a PhD candidate in the Moore Lab, Romina Piunno tackles many challenges that have direct impact on climate change and one of her research interests include convective processes in the Labrador Sea. 

Convection in the Labrador Sea is a crucial component of the ocean’s meridional overturning circulation where it transports water towards north and south. As part of this process, water gets transported not only at the surface level but also at a greater depth to compensate for the surface level transport. Labrador Sea is one of the few global locations where this surface and deep ocean waters mix, allowing the ocean to redistribute heat and ventilate. This process is also crucial for Earth’s climate system. Deep mixing will only take place if the surface of the ocean is cooled enough for it to become denser than the water below, and since the ocean is heated from above by the Sun the cold winds from Canada during winter appear to initiate the process.

Gases such as oxygen and carbon dioxide get mixed into the water, a process essential to marine life, and the carbon dioxide at the atmosphere gets absorbed as part of the process. Increased level of carbon dioxide at the atmosphere will cause the global temperature to rise causing the greenhouse effect. Therefore, understanding factors that influence convection and the overturning circulation processes both at the atmospheric and the oceanographic perspectives is crucial.

Romina’s research work emphasizes heavily on the atmospheric processes; therefore, this collaboration with oceanographers was essential to gain knowledge on the modelling of oceanographic processes. 

As part of the Department of Chemical and Physical Sciences’ Research Visit Program, Romina visited the Geophysical Institute at the University of Bergen and collaborated with Professor Kjetil Våge and his research group. During the visit, Romina’s work was centred around modeling studies and analysis of characterizing the effects of large-scale atmospheric circulation on ocean mixing in the Labrador Sea. 

From this research visit collaboration, Romina studied how atmospheric cooling affects the Labrador Sea’s mixing, focusing on the North Atlantic Oscillation (NAO) and the Icelandic Low (IL). The NAO based on the surface sea-level pressure difference between Iceland and the Azores influences local wind speed and direction, affecting cooling rates of the ocean around it. And a strong NAO drives effective cooling winds from the North-West while the IL’s variable winds are less effective at triggering sea water mixing despite its proximity to the Labrador Sea.

As a result of this visit, Romina was able to acquire ocean modeling and data analysis skills and is waiting to have a manuscript accepted by the Journal of Geophysical Research: Oceans.