Leo J. Donner
Lecturer, Program in Atmospheric and Oceanic Sciences
Physical Scientist, Geophysical Fluid Dynamics Laboratory
Research Interests: Cloud and Convective Processes in the Atmospheric General
Cloud and convective systems play important roles in the energy and water
cycles in the atmosphere and are thereby important in a wide range of problems
related to climate and large-scale atmospheric variability on shorter time
scales. My research deals with the interactions between processes on the
scales of clouds and convective systems and large-scale atmospheric flows.
Several methods are used to study the effects of clouds and convective systems
on the thermal, moisture and radiative fields which characterize the large-scale
flows in which these systems develop. A primary application of this research
is the development of parameterizations for clouds and convective systems
for use in general circulation models.
Recent research has centered on ice clouds and deep cumulus convection.
The factors which determine the distribution of atmospheric ice and its
consequences for climate are under examination. A unified procedure for treating
the thermodynamic, hydrological, and radiative interactions between deep
convective systems and large-scale flows has been developed. Both ice clouds
and deep cumulus convection play important roles in climate and climate
change. General circulation models and high-resolution, limited-area cloud-system models are used in these studies, and data from satellite observations and field
experiments are also employed. Some issues related to the role of cumulus
convection in numerical weather prediction have also been addressed.
Course: GEO 547. Atmospheric Thermodynamics and Convection
The course explores the thermodynamics of water-air systems. It gives an
overview of atmospheric energy sources and sinks. Planetary boundary layers,
closure theories for atmospheric turbulence, cumulus convection, interactions
between cumulus convection and large-scale atmospheric flows, cloud-convection-radiation
interactions and their role in the climate system, and parameterization
of boundary layers and convection in atmospheric general circulation models
are also studied.