HR: 08:00h
AN: SA41A-01 INVITED     [PDF]
TI: The Mesopause as a Physical Boundary
AU: * ReVelle, D O
EM: revelle@lanl.gov
AF: Los Alamos National Laboratory, P.O. Box 1663, MS D401, Los Alamos, NM 87545 United States
AB: Large quantities of meteoric material impact the Mesopause region on a global scale. In this highly elevated region of the atmosphere where, large man-made vehicles first encounter the near-continuum flow regime (the so-called entry interface), there is a complex interplay of air chemistry, charged meteoric aerosol debris in the presence of water vapor, the presence of the Sodium and other metallic layers, solar electromagnetic radiation absorption, terrestrial infrared radiation cooling in the presence of a rapidly changing dynamic circulation pattern, height variable mean molecular weight, etc. In addition, there are also individual wake ionization effects and coupling with the lower ionosphere aloft as well as the presence of strong vertical shear of the horizontal wind and subsequent atmospheric turbulence and propagating neutral gravity and tidal waves, etc. This region of relatively small pressure (density) scale height acts as a physical boundary (for a range of sizes, entry velocities, entry angles, bulk densities or volume porosities, etc.) to the penetration of meteoric material through the atmosphere. We will illustrate this process using recently developed and interconnected highly detailed hydrodynamic and non-hydrodynamic models (including detailed fragmentation processes and panchromatic luminosity generation as well as infrasound generation, etc.) that are applicable to all sizes and type of meteors and meteor-fireballs. Expected effects of this meteoric population on the Mesopause region will be examined.
DE: 0340 Middle atmosphere--composition and chemistry
DE: 0341 Middle atmosphere--constituent transport and chemistry (3334)
DE: 0342 Middle atmosphere--energy deposition
DE: 3332 Mesospheric dynamics
DE: 6205 Asteroids and meteoroids
SC: SPA - Aeronomy [SA]
MN: 2003 Fall Meeting