October 20, 2021 - 3:00 pm
October 20, 2021 - 4:00 pm
CategoriesWeather and Climate Systems
Weather and Climate Systems
The Role of Cloud-Radiation Interactions in Accelerating Tropical Cyclone Development
Wednesday, October 20
This study examines how cloud-radiation interactions affect the development of tropical cyclones (TCs) using satellite measurements and idealized model simulations. A complete understanding of TC genesis remains unclear. Recent studies used idealized models under radiative-convective equilibrium to demonstrate the important role of radiative heating in accelerating the development of convective systems. A recent study using CloudSat measurements showed that intensifying TCs tend to have greater ice water content across 500 km of the TC center. Such extensive increase of cloud ice in intensifying TCs may provide extra radiative heating to bolster TC development. To examine the impact of cloud radiative heating on the development of storms, we used NASA Clouds and the Earthâ€™s Radiant Energy System (CERES) data set to calculate the amount of cloud radiative heating in each 2001 to 2011 storm over the Atlantic Ocean. The results demonstrate that developing TWs and TCs on average have a greater amount of cloud radiative heating than non-developing groups: cloud radiative heating in developing TWs and TCs is greater within five degrees latitude/longitude of the storm center, while it is less outside five degrees latitude/longitude, than do non-developing TWs and TCs. The clear structural differences between developing and non-developing storms inspired us to use the Weather and Research Forecasting model (WRF) in order to examine the effect of cloud radiative heating on the development of storms. We conducted two sets of simulations, one with regular cloud radiative heating and the other without cloud radiative heating from longwave. We found that storms with cloud radiative heating tend to develop with faster rates than those without cloud radiative heating from longwave, especially for storms at the weaker end of the intensity spectrum. These results imply that cloud-radiative interactions may be crucial to trigger the development of TWs and TCs at the early stage.