Professor, Atmospheric Sciences
University of Utah
135 S 1460 East Rm 819 (WBB)
Salt Lake City, Ut 84112-0110
University of Washington, Ph.D. Atmospheric Sciences, 2000
University of Washington, M.S. Atmospheric Sciences, 1995
University of Waterloo, B.Sc. Honours Physics, 1992
My research focus is in the field of cloud physics. Clouds are interesting because
they display such an extraordinarily wide range of interactive physical processes,
and understanding these is critical for improving weather and climate forecasts. My
work also includes development of simple physical models for understanding civilization
growth. While the two may seem disconnected, it looks like both clouds and civilization
are complex systems that evolve according to the same non-equilibrium thermodynamic
Much of this work is done in collaboration with graduate students in the ACCS group. Some involves pencil and paper, PCs or parallel computing environments. There is also laboratory work. With engineer Cale Fallgatter, we build instruments for photographing snowflakes in freefall in the Cloud Physics Laboratory at the University of Utah. These are deployed to our High Altitude Research Laboratory for Diversity in Snow (HARoLDS) at Alta Ski Area in Utah s Wasatch Front.
When not involved in research, I teach graduate and undergraduate classes in Cloud Physics, Atmospheric Radiation and Thermodynamics, and I serve as a co-editor for the Copernicus open access journal Atmospheric Chemistry and Physics.
Short-lived pollutants in the Arctic: their climate impact and possible mitigation
strategies (Journal Article), 2008
Extinction coefficients retrieved in deep tropical ice clouds from lidar observations
using a CALIPSO-like algorithm compared to in-situ measurements from the Cloud Integrated
Nephelometer during CRYSTAL-FACE (Journal Article), 2007
Clouds play a key role in climate by removing pollutants from the atmosphere, shielding
the Earth from sunlight, and by acting as pistons in the atmospheric heat engine.
But they are also extraordinarily dynamic over a vast range of interacting scales
in time in space, and this makes them difficult to understand. Is their role in climate
fundamentally simple (which would be nice) or impossibly complex (a cause for despair)?
Our group works to tease from clouds their contributions to various atmospheric chemical,
dynamic, microphysical and radiative processes.
A second focus is development of a thermodynamic basis for interpreting the evolution of the global economy, and its relationship to atmospheric concentrations of carbon dioxide. Central to the model is the finding that civilization's economic value or wealth, when adjusted for inflation, is linked to its rate of primary energy consumption through a constant.
Research Keywords, Regions of Interest and Languages:
Keywords: Atmospheric Physics (2); Climate Change (10); Cloud Physics (4); Energy Economics (2); Chemical Transport; Global Change (3); Greenhouse Gases (2); Precipitation (5)
Regions: Arctic Ocean (2)
Courses I Teach
ATMOS 6020 Fundamentals of Physical Meteorology
ATMOS 6200 Atmospheric Radiation
ATMOS 5140 Physical Meteorology II: Atmospheric Radiation