Research

Ocean circulation encompasses motions on a wide range of spatial and temporal scales. The greatest challenge to a physical oceanographer is to understand how these motions interact with each other and how these interactions determine the oceanic state and the Earth’s climate. To understand these complex processes, our research group uses a combination of numerical simulations, theory and observational data.

Dynamics of Mesoscale Currents

Mesoscale (spatial scales of 10-100km) currents are generated and influenced by the large-scale (hundreds and thousands of kilometers) flows. Understanding of the importance of the mesoscale for large-scale dynamics remains a long-standing challenge in Physical Oceanography. For the past decade, our group has been studying a tendency of mesoscale eddies to induce persistent, nearly zonal flows in the oceans. Similar flows are clearly visible in the atmospheres of giant planets (e.g. Jupiter, Saturn) as zonal jets, and are known to exist in plasma flows. 

Role of Mesoscale Currents in Distribution of Properties

Oceanic advection and mixing influences the Earth’s climate in several ways. Distribution of heat anomalies plays a critical role in the energy budget of the Earth system and in sea-level rise. Uptake, transport and storage of various components of the oceanic bio- and geo-chemical cycles, including anthropogenic carbon, effectively control the atmospheric concentrations of greenhouse gases. While the importance of large-scale circulation in distribution and air-sea exchanges of these quantities has been known for some time, the significance of mesoscale currents in these processes is only beginning to emerge. Our research explores the significance of mesoscale currents in these processes, using both highly idealized and most comprehensive numerical models of ocean circulation.

Role of mesoscale currents in air-sea interactions

As air blows over sharp fronts in Sea-Surface Temperature (SST), the atmosphere cannot fully adjust, which leads to significant effects on air-sea interaction. In parts of the oceans where the mesoscale advection is strong, the resulting SST anomalies drive the air-sea exchanges, by forcing the atmosphere to adjust and act to reduce these anomalies. These processes challenge the traditional view on the upper ocean as a passive player responding to atmospheric variability. Our group uses idealized regional and comprehensive global atmosphere-ocean models to study the importance of mesoscale eddies in air-sea interactions.

Observing System Simulation Experiments

Observing System Simulation Experiments (OSSEs) can help interpretation of existing observing systems and guide the design of the new ones. OSSEs are beginning to accompany all new observational efforts. OSSEs are run using most realistic ocean models, where the accuracy of the reconstruction of various oceanic fields can be quantified. Our most recent studies assist the development of a new biogeochemical array, as a part of the Southern Ocean Carbon and Climate Observations and Modeling (SOCCOM) project.