This is a Faculty Early Career Development (CAREER) project to support a junior faculty member in developing and conducting an integrated 5-year program of research and education in atmospheric science. The research component is a study of the mechanisms which govern the temperature structure of the Tropical Tropopause Layer (TTL), the layer of the upper troposphere and lower stratosphere between about 200mb (roughly the level of tropical convective outflow) and 70mb. The TTL is scientifically interesting because it contains the interface between the troposphere and stratosphere, including the cold point tropopause (around 100mb), and conditions in the TTL control the entry of atmospheric tracers into the stratosphere, including water vapor. Water vapor is of particular interest due to its strong radiative effects, and because of the role of stratospheric clouds in the formation of the ozone hole. The amount of water vapor entering the stratosphere in turn depends strongly on temperature in the TTL, and temperature is determined by a variety of mechanisms from individual convective plumes to planetary-scale circulations. This project explores the full range of mechanisms using a hierarchy of numerical models, including single-column radiative-convective model, a cloud resolving model with a pan-tropical domain, and a comprehensive chemistry-climate model. The project will attempt to understand why temperature continues to decrease with height between the convective cloud tops and the cold point tropopause, and the processes which drive temperature variability within the TTL.
The educational component of the project seeks to introduce students and the general public to atmospheric science through "tales of great discoveries". The goal of the activity is to teach science from a historical perspective, emphasizing science as a human and social endeavor that occurs within a particular historical context. This approach has been used to teach physics to general audiences, and studies show that the historical approach can make physics more approachable for non-specialists. But despite the success of this approach for physics it has not been developed previously atmospheric science. Through this award the PI will work with the outreach program at the Center for Multiscale Modeling of Atmospheric Processes (CMMAP) to present several tales of discovery, including the discovery of the tropopause and stratosphere, the discovery of the Brewer-Dobson circulation, the discovery of the Quasi-Biennial Oscillation, and the discovery of the ozone hole.
