Role of Mesoscale Ocean Dynamics in Air-Sea Coupling over the Southern Ocean

University Of Miami, Coral Gables FL

Investigators

Abstract

The atmosphere and ocean interact on a wide range of spatial and temporal scales, and these interactions modulate weather and climate variability, as well as oceanic uptake of anomalous heat and carbon. At the oceanic mesoscale (about 10 to 100 km scales), advection is sufficiently strong to create strong gradients in sea surface temperature. As air blows across these very sharp fronts, the atmosphere cannot fully adjust, which leads to significant effects such as atmospheric cooling (warming) of warm (cold) sea surface temperatures. These effects are well pronounced in the Southern Ocean, where powerful mesoscale variability abounds. The main goal of this project is to explore mesoscale atmosphere-ocean interactions in the Southern Ocean and to understand how the ocean mesoscale creates sharp sea surface temperature fronts that modulate these interactions. This study will serve to inform global climate modeling efforts in terms of the identifying the key processes and required ocean resolution needed to correctly capture air-sea interactions. The project will advance a career of a female investigator and will train two graduate students in the fields of Physical Oceanography and Climate Science. Atmosphere-ocean coupling at mesoscale plays an important, but poorly understood role in climate variability, atmosphere and ocean dynamics, uptake of atmospheric gases and biogeochemistry. Understanding of this coupling has large practical importance for climate modeling, because a vast majority of climate models cannot fully resolve the mesoscale, which leads to biases in the simulations. The main hypothesis of this project is that a significant part of the sea surface temperature anomaly variability at the oceanic mesoscale is driven by mesoscale oceanic advection. The analysis will be carried out in a fully coupled model system in which mesoscale sea surface temperature anomalies both affect and are affected by the atmosphere, and the study will employ a blend of advanced theoretical considerations, comprehensive coupled simulations and targeted idealized studies, all with high resolution in the ocean. The particular focus of this study is on the Southern Ocean, both because of its large role in climate and because mesoscale variability is ubiquitous there, but our conclusions are expected to be relevant to the other parts of the World Ocean. One particular strength of this research is the merging of comprehensive climate simulations with a combination of idealized modeling and theory, in a fully coupled regime and with dynamically consistent mesoscale ocean circulation.