Environmental Science and Engineering Seminar

Wednesday May 18, 2022 4:00 PM

Acceleration of tropical cyclone development by cloud-radiative feedbacks

Speaker: Allison Wing, Florida State University
Location: South Mudd 365

A complete understanding of the development of tropical cyclones (TC) remains elusive and forecasting TC intensification remains challenging. Furthermore, while global climate model (GCM) simulation of TCs has improved significantly in recent years, significant biases remain. This motivates further research into the physical processes that govern TC development as well as the development of process-oriented diagnostics for GCMs, to identify processes to target for model improvement.

Here, I investigate the importance of radiative feedbacks in TC development and the mechanisms underlying their influence is investigated in a set of idealized convection-permitting simulations. Tropical storm formation is delayed by a factor of two or three when radiative feedbacks are removed and the TC's intensification rate is greater when longwave radiative feedbacks are stronger. Radiative feedbacks in the context of a TC arise from interactions between spatially and temporally varying radiative heating and cooling (driven by the dependence of radiative heating and cooling rate on clouds and water vapor) and the developing TC (the circulation of which shapes the structure of clouds and water vapor). Further analysis pinpoints the longwave radiative feedback contributed by ice clouds as the strongest influence. Improving the representation of cloud-radiative feedbacks in forecast models therefore has the potential to yield critical advancements in TC prediction.

Series Environmental Science and Engineering Seminar

Contact: Bronagh Glaser bglaser@caltech.edu
For more information visit: http://ese.caltech.edu/seminars