The Ocean, Ice and Atmosphere Dynamics group carries out a wide range of research centered around four major themes/ areas. The areas and the associated faculty members are:
Atmospheric Dynamics is the study of winds on scales ranging from thunderstorms and smaller to cyclones and the global circulation. It seeks to understand the processes that generate waves, weather and turbulence. Understanding atmospheric dynamics is essential not only to weather prediction, but also to determining long-term climate change; for example, how rainfall patterns will change response to ongoing changes in radiative forcing. A distinctive aspect of atmospheric dynamics is winds advect moisture, and moisture contains latent heat, which may be released to heat the air, and thus feed back on to the winds.
Photo Credit: NASA's Goddard Space Flight Center
Dust, salt and smoke swirling in the air during the 2017 hurricane season from the Goddard Earth Observing System (GEOS) computer model
Geophysical Fluid Dynamics
Geophysical fluid dynamics differs from other branches of fluid dynamics in that it deals with flows for which rotation and stratification are important. Rotation introduces a Coriolis force and stratification introduces buoyancy. Both profoundly affect the dynamics of fluid flows. For example, the rates and even the direction (large-to-small or small-to-large scale) of turbulent cascades are profoundly affected. Additionally, new wave types and hydrodynamics instabilities are introduced. Classically, various flow regimes have been studied more or less in isolation. Today, increased computational power permits us to instead consider flows covering a large range of scales (thus spanning two or more of these flow regimes) and the focus is often on how these different regimes interact. Geophysical fluid dynamics is fundamental to understanding of atmospheric and ocean dynamics.
The vorticity field in a high-resolution numerical simulation of decaying two-dimensional turbulence from random initial conditions (Photo Credit: P. Bartello)
Ocean dynamics is the study of the motion of water within the ocean and includes scales ranging from turbulence (millimeters and milliseconds) to the global ocean circulation (thousands of kilometers and centuries). Ocean dynamics strongly influences the movement of sea ice and of the atmosphere, and the distribution of biological and biogeochemical tracers. Understanding ocean currents, mixing, eddies, waves and tides is key to grasp the role of the ocean in the climate system.
Photo Credit: NASA/Goddard Space Flight Center Scientific Visualization Studio
Ocean surface currents from the Estimating the Circulation and Climate of the Ocean, Phase II (ECCO2) model
Sea Ice Dynamics
Sea ice in the Arctic and the Southern Ocean moves under the action of surface wind and ocean stresses and in accordance with its own internal dynamics. This produces ridges where ice floes are pushed together and leads (open water) where they are pulled apart. Unlike fluids such as air and water, motion of sea ice occurs primarily at the boundary between ice floes, e.g., with two ice floes on opposite sides of a lead moving at different speeds. Leads in the sea ice field also impact air-sea heat exchange, with the oceans giving up large amounts of heat to the atmosphere in summer and absorbing large amounts in summer.The study of sea ice dynamics, including how and when leads form and the motion of ice floes on either side are key to a proper representation of the sea ice cover in ocean models which, in turn, is essential to understanding the fate of sea ice itself.
Photo credit: Charles Brunette (PhD student)
Installation of an internal Ice Stress Buoy (ISB) deployed on landfast sea ice south of Satosoak Island, near Nain in February 2019. From left to right: auger used to drill through the ice cover; sensors inserted in sea ice at different depths that measure stress in sea ice; data logger and beacon transmitting data in real time.