Our group is interested in clouds and convection in the earth’s atmosphere. Clouds play a role in most atmospheric phenomena of interest to society: weather, climate, hurricanes, severe storms, pollution, and so forth. Clouds pose many interesting, unsolved problems!  To address these questions, we use theory, numerical models, and aircraft observations.

Cloud parameterization:  A typical weather forecast model solves for temperature, moisture, and so forth at points tens of kilometers apart.  A climate model has even coarser resolution. Many important clouds are smaller than this, and they must be handled in some way.  This fascinating and challenging endeavor is called “cloud parameterization.”  Such cloud parameterizations lend the various extant atmospheric models their character.  It is only a moderate exaggeration to say that the cloud parameterization is the model (or at least the atmospheric, dynamical part of it).  We are developing an advanced cloud parameterization.  We strive as much as possible to construct a parameterization that is general and is based on first principles. Past results.

Carbon cycle: Some of the carbon dioxide emissions that are caused by human activities are taken up by vegetation. The amount of uptake in various regions of the globe is still a matter of controversy. Past results.

Altocumulus and altostratocumulus clouds:  These are thin layer clouds that reside in the mid levels of the atmosphere and have rounded elements.  Although there has been intense study of stratocumulus clouds near the ground and cirrus clouds aloft, there has been relatively little study of alto clouds.  Yet there are compelling reasons to investigate them. Alto clouds form an excellent laboratory with which to study cloud processes because they are simpler than many other cloud types. Furthermore, they pose an icing hazard to small aircraft, and influence the vertical distribution of thermal and solar radiation. Past results.

Dry atmospheres in radiative-convective equilibrium:
Radiative-convective equilibrium is a simple prototype for vertical motions in the atmosphere.  We take an idealized, theoretical approach in the hopes of moving step-by-step from well-established laboratory results toward more realistic atmospheric flows. Past results.