Dr. Boos studies the processes responsible for variations in tropical climate over a broad range of time scales, using theory, numerical models, and observational analyses. He has worked most extensively in monsoon dynamics, attempting to improve the understanding and prediction of these tropical circulations that deliver water to billions of people. Such planetary-scale circulations in the tropical atmosphere are poorly understood because they depend strongly on the heat released when water vapor condenses and falls out as precipitation, a process that occurs on short length scales that are extremely difficult to resolve in global models of climate. To address this problem, Dr. Boos uses high resolution computer models of the atmosphere in limited domains to represent the transfer of energy between moist convective scales and idealized planetary-scale circulations. He employs these models, together with data from satellites and in-situ measurements, to verify and guide development of theories for the variability of the tropical atmosphere.