Aerosol effects on microstructure and intensity of tropical cyclones

The US Department of Homeland Security (DHS) organized a workshop in February 2008 named the Hurricane Aerosol Microphysics Program (HAMP)to develop a program to study the potential for tropical cyclones (TC) mitigation in the wake of the disaster inflicted on the United States by Hurricane Katrina. Penetration of continental aerosols to the TC periphery caused by the TC circulation approaching the land was simulated. As a result of the aerosol penetration, concentration of cloud condensation nuclei (CCN) increased at the TC periphery from 100 to about 1,000 cm ³. Under HAMP funding a numerically efficient 2D large-eddy simulation model was developed that revealed dynamical interactions between the clouds, roll vortices, and internal gravity waves. A clear example of the effects of aerosols on TC cloud microstructure was also presented for Typhoon Nuri, which made landfall in Hong Kong on 21 August 2008.