HR: 16:00h
AN: SA24A-01    [Abstracts]
TI: Comparisons of PMSE Ice Particle Simulations With Observations From the DROPPS Rocket Campaign
AU: Goldberg, R A
EM: richard.a.goldberg@nasa@gov
AF: NASA/GSFC, Code 690.4, Greenbelt, MD 20771 United States
AU: * Webb, P A
EM: pwebb@lepvax.gsfc.nasa.gov
AF: Nomad Research, Inc, Code 690 NASA/GSFC, Greenbelt, MD 20771 United States
AU: Pesnell, W D
EM: pesnell@nomadresearch.com
AF: Nomad Research, Inc, P. O. Box 796, Arnold, MD 21012 United States
AB: The origin of polar mesospheric summer echoes (PMSEs) and their proposed relationship to dust and aerosol particles and to noctilucent clouds (NLCs) are among the most pressing questions governing the physics of the polar summer mesosphere. Recent studies show increasing evidence for the presence of these particles, and their importance particularly in a charged state. One theory for the formation of the PMSE particles is that they are composed of a rocky core of meteoritic origin, which acts as a seed about which an ice mantle forms. Computer simulations have been conducted to model the flight trajectory and sublimation of spherical ice/rock particles with radius of 0.5 - 6.0 nm through the Particle Impact Detector (PID) charge telescope onboard two rockets that were part of the DROPPS (Distribution and Role of Particles in the Polar Summer Mesosphere) campaign. DROPPS involved two rocket sequences in July, 1999 launched from Andoya, Norway. The first launch sequence was nighttime (July 5-6) during the presence of a strong PMSE and a weak NLC. The second sequence (July 13-14) occurred during a bright NLC, but with no PMSE present. By comparing the PID observations from these two flights with the computer simulations, information about the properties of the PMSE particles, including their core size, ice mantle thickness and distribution, can be deduced.
DE: 0305 Aerosols and particles (0345, 4801)
DE: 0320 Cloud physics and chemistry
DE: 0340 Middle atmosphere--composition and chemistry
DE: 0394 Instruments and techniques
SC: SPA-Aeronomy [SA]
MN: 2004 AGU Fall Meeting