M. Joan Alexander Sr. Research Scientist

Publications - Research - Field Campaigns - Vitae - Miscellaneous - Contact

In order to better predict the weather and better understand climate change, many atmospheric scientists are involved in developing computer simulations that describe the global circulation of the atmosphere. These global circulation models (GCMs) cannot explicitly resolve all of the scales of phenomena important in the atmosphere, so they use parameterizations of some of the smaller-scale processes, such as clouds, precipitation, and many others including the effects of small-scale atmospheric waves on the circulation.

My research focuses on atmospheric waves, and specifically on atmospheric gravity waves that have horizontal wavelengths in the range of about 10 to 1000s of km. These waves are poorly described in GCMs, yet they can have dramatic effects on the global-scale circulation, so they must be parameterized. Their small scales have made global observations of their properties and occurence difficult. Our understanding of them is therefore relatively new, and therefore still very incomplete. My research focuses on developing the needed understanding through observations and observational analyses, and through computer modeling of gravity wave sources, their propagation through the atmosphere, and their interaction with the larger-scale circulations.

Research Projects:

• Observing Gravity Waves from Space


1. AIRS: Atmospheric Infrared Sounder
2. MLS: Microwave Limb Sounder
3. CRISTA: Cryogenic Infrared Spectrometers and Telescopes for the Atmosphere
4. HIRDLS: High Resolution Dynamics Limb Sounder
5. Waves Explorer: A space science proposal to observe atmospheric gravity waves and their effects on the middle and upper atmosphere


• Gravity Wave Effects in Global Circulation Models


1. Parameterization of Gravity Wave Mean-Flow Forcing
2. GCM Studies


• Gravity Wave Generation by Storms



• Atmospheric Waves Observed with High Altitude Aircraft and Balloon-Borne Instruments