Preliminary Analysis of Aerosol Particle Deposition in the Middle Atmosphere

抄録

The residence time of a particle in the upper atmosphere has been of interest to scientists and astrobiologists. However, only a few comprehensive studies that consider atmospheric conditions and solar radiation in detail have been reported. This study simulates the speed of deposition or levitation of a particle controlled by solar pressure, solar radiation, friction from the air, and gravity. The simulation results showed that the particle motion was significantly affected by gravity, friction from the air, and the photophoretic force caused by solar radiation and thermal gradients inside a particle. As mentioned in previous studies, this study confirmed that a particle could levitate in the mesosphere and stratosphere when it is small enough (≦100 nm for alumina particle; ≦1 μm for water particle). Thus, we conclude that the results of this study are useful for the development of a precise simulation of aerosol dynamics in the stratosphere and mesosphere.