Particle Microphysical Timescales in Hot Atmospheric Clouds

Abstract:

We apply particle microphysical theory to estimate timescales for aerosol formation and growth processes under extreme atmospheric conditions. In the presence of temperatures exceeding 4,000 degrees Kelvin, solid materials, like oxides of iron, aluminum, and silicon, can be entrained into a hot atmospheric cloud and vaporized. As the cloud cools and quenches, the hot vapors are depleted through competing pathways. They can start to form new particles through aerosol nucleation or can condense on existing particles. The particle size distribution also changes over time through coagulation. Using aerosol dynamical equations modified for extreme conditions, we describe our efforts to constrain microphysical timescales in a hot atmospheric cloud using experimental data from a plasma flow reactor system. We also describe ongoing work to create a microphysics model for predicting particle size distributions resulting from high energy explosions.