Trends and Variability of Temperatures near the Tropical Tropopause Layer and Implications for Tropical Cyclones

This project will enhance understanding of atmospheric physics, chemistry, and dynamics on tropical cyclone activity. It will advance scientific confidence in projections of the influence of climate change on tropical cyclones. Linkages across chemistry, radiation, dynamics, and meteorology provide an ideal framework for the type of cross-disciplinary education needed for the next generation of climate scientists.

Understanding of the factors that influence tropical cyclones has broadened in recent years to include consideration of the tropical tropopause layer (TTL), which can affect storm outflow temperatures and thereby potential and actual intensities. Observations from multiple sources show that the atmosphere in the vicinity of the TTL exhibits substantial variability on interannual and decadal timescales, which could affect variability and trends in tropical cyclones. However, the physical and chemical processes affecting these changes are not well understood, and reanalysis products and coupled general circulation models often do not agree on the magnitude of this variability. The effects of changes in volcanic aerosol, water vapor, and ozone in a hierarchy of radiative and chemical/dynamical modeling approaches will be examined, and implications of radiative processes for tropical cyclones will be identified.