RESEARCH INTERESTS
The atmospheric boundary layer
The most
rapid and greatest transports of energy, mass and momentum occur within
the atmospheric layer extending from the ground surface to an altitude
of about 1500 meters (daytime). This region of the atmosphere is the so
called atmospheric boundary layer and its thermodynamics and kinematics
undergo pronounced diurnal changes in response to the
surface-atmosphere exchanges of energy, mass and momentum. During the
last decade, collaborating with collagues such as Michael Garstang,
Alan Betts and many others I have conducted feld campaigns to
investigate (1) the dynamics of the atmospheric boundary layer and (2)
the links between surface-based processes, such as evapotranspiration
and ozone dynamics, with the deeper atmosphere. The field research has
been achieved in places such as the Amazonia of Brazil, the Marshall
Islands, the southern boreal region of Canada and the Canadian high
Arctic. In all field campaigns, we have contributed with the
development and deployment of state-of-the-art instrumentation on
towers, tethered balloons, and "free balloons" to learn the rates of
atmospheric turbulent transport of materials from the surface to the
deeper atmosphere and vice versa. The purpose of this type of research
is to investigate how much water vapor moves from the tropical
continental and oceanic surfaces to the cloud sublayer. Some of this
research is in support of NASA’s Tropical Rainfall Measuring Mission
(TRMM) satellite. When water evaporates, large amounts of energy are
needed. Most of the evaporated water rises to deep levels in the
atmosphere, cools and condenses to form clouds. But as water condenses,
the energy invested in evaporation is released back into the
environment, thus warming the atmosphere. Because tropical clouds grow
deep into the atmosphere (5-8 km), the energy released when water
condenses is left behind. Due to the global circulation patterns of the
Earth’s atmosphere, this energy can then be transported from tropical
to extratropical regions. This is one manner in which the atmosphere
can transport heat from energy-surplus to energy-deficit regions.
Our most current field projects are taking place in the Canadian high
Arctic (at Alert, Nunavut, Canada), Senegal (west Africa), New Mexico,
and the Piedmont of central Virginia.
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