McGillis and David Ho collect samples from the ocean at Columbia
University's Biosphere 2. Photo by Benjie Sanders, Arizona
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Global Effects: Investigating Air-Water
Transfer of heat, mass, and momentum
across the air-water interface is a result of many physical, chemical,
and biological factors that occur at the water surface. Understanding
the principal factors controlling air-water fluxes is crucial in determining
how surface processes regulate the variability of climate, weather,
and biological activity.
Particularly when estimating the global
carbon balance and predicting the amount of carbon dioxide in the
atmosphere, accurate quantification of gas exchange at the air-water
interface is needed.
Dr. McGillis specializes in understanding
the physical processes that occur at the air-water interface. His
research has included numerous cruises to ocean areas that act as
sources and sinks for carbon dioxide and other gases as well as the
development of the Martha's
Vineyard Coastal Observatory. Currently, Dr. McGillis is focusing
on coastal, lake, riverine, and estuarine air-water exchange to determine
how these areas affect the global carbon budget. He is also a Surface
Ocean Lower Atmosphere Study (SOLAS) committee member and is collaborating
with scientists in the development of an international SOLAS summer
school. His technical background centers on physicochemical flow,
including the transport of heat and mass associated with phase-change
processes, the thermodynamics of two-phase and fluid-phase equilibria,
the mechanisms of evaporation, condensation, nucleation, bubble growth
and two-phase fluid flow, and the fundamentals of turbulence. Dr.
McGillis has investigated these processes in field experiments and
theoretical models, while helping to develop new direct covariance
methods of measuring gas transfer.
Measurements of gas transfer, surface
statistics, and surface concentrations will lead to a better understanding
of air-water gas transfer, which is necessary for accurate climate
modeling. The challenge in this work is in deciphering the magnitude
of parameters affecting gas transport mechanisms. Dr. McGillis has
addressed many fundamental transport issues in vapor-liquid systems
with differential diffusion, and is continuing to address gas transport
at the air-water interface on a global level.