Allison Wing, FSU: Tropical Cyclone Development

COMPASS 2024-01-19: Allison Wing, Florida State University
"Acceleration of Tropical Cyclone Development by Cloud-Radiative Feedbacks"

A complete understanding of the development of tropical cyclones (TC) remains elusive, and forecasting TC intensification remains challenging. This motivates further research into the physical processes that govern TC development. I find that a "cloudy greenhouse effect" accelerates TC development, in which anomalous infrared warming in areas of deep thunderstorm clouds near the center of theTC drives rising motion in the storm, which helps moisten the atmosphere and aids in the formation of the TC's circulation. Improving the representation of cloud-radiative feedbacks in forecast models therefore has the potential to yield critical advancements in TC prediction, but this requires a better understanding of cloud-radiative feedbacks in observed TCs. Thus I also present ongoing work that investigates these processes using satellite (CloudSat) retrievals of cloud properties. We examine the vertical and radial structure of ice and liquid clouds and the implications of the heterogeneous cloud distribution for spatial variability in radiative heating rates. Radiative transfer calculations using the CloudSat cloud property retrievals indicate that most of the spatial variability in longwave heating rates comes from ice clouds, as in the idealized simulations. The longwave cloud radiative feedback is found to be strongest in the inner core of TCs undergoing rapid intensification.