HR: 08:50h
AN: SA21B-04 INVITED     [Abstracts]
TI: The Cosmic Dust Input in the Atmosphere of the Earth
AU: * Horanyi, M
EM: horanyi@colorado.edu
AF: LASP and Department of Physics, U. of Colorado, Boulder, Co 80309 United States
AB: Dust of extraterrestrial origin continuously enters our atmosphere and is now recognized to play a significant role in the chemistry and the dynamics of the mesosphere. For example, the formation of Noctilucent Clouds (NLC), Polar Mesospheric Clouds (PMC), Polar Mesospheric Summer Echoes (PMSE), are all thought to be related to the condensation of water vapor onto nm sized nucleation seeds. Interplanetary dust particles are a significant source of nucleation seeds. They typically enter the atmosphere at high enough speeds to fully evaporate and deposit most of their mass in the altitude range of 80-90 km. Our understanding of the cosmic dust input is based on different observational methods, including in situ dust detectors and ground based radars. Though there is a growing interest for decades, the amount of dust deposited, its size distribution, its spatial and temporal variability remain purely known. In this talk I will summarize our current (non)understanding of the dust deposition rate and its variability, and point to contradictory conclusions from radar and in situ measurements. The upcoming observations by the Cosmic Dust Experiment (CDE) onboard the Aeronomy of Ice in the Mesosphere (AIM) mission will also be described, including its capabilities and limitations to contribute to our understanding of cosmic dust input into our atmosphere.
UR: http://aim.hamptonu.edu/
DE: 0305 Aerosols and particles (0345, 4801, 4906)
DE: 2129 Interplanetary dust
DE: 2442 Meteor-trail physics
SC: SPA-Aeronomy [SA]
MN: Fall Meeting 2005