HR: 1340h
AN: V43C-1434    [Abstracts]
TI: Organic Haze Aerosols on the Early Earth: A Laboratory Investigation
AU: * Trainer, M G
EM: melissa.trainer@colorado.edu
AF: Department of Chemistry and Biochemistry and CIRES, University of Colorado at Boulder, UCB 216 CIRES 318, Boulder, CO 80309-0216 United States
AU: DeWitt, H L
EM: helen.dewitt@colorado.edu
AF: Department of Chemistry and Biochemistry and CIRES, University of Colorado at Boulder, UCB 216 CIRES 318, Boulder, CO 80309-0216 United States
AU: Pavlov, A A
EM: pavlov@lasp.colorado.edu
AF: Laboratory for Atmospheric and Space Physics, University of Colorado at Boulder, UCB 392, Boulder, CO 80309-0392 United States
AU: Jimenez, J L
EM: jose.jimenez@colorado.edu
AF: Department of Chemistry and Biochemistry and CIRES, University of Colorado at Boulder, UCB 216 CIRES 318, Boulder, CO 80309-0216 United States
AU: McKay, C P
EM: cmckay@mail.arc.nasa.gov
AF: Space Sciences Division, NASA Ames Reserch Center, Moffett Field, CA 94035 United States
AU: Worsnop, D R
EM: worsnop@aerodyne.com
AF: Aerodyne Research, Inc., 45 Manning Road, Billerica, MA 01821-3976 United States
AU: Toon, O B
EM: btoon@lasp.colorado.edu
AF: Laboratory for Atmospheric and Space Physics, University of Colorado at Boulder, UCB 392, Boulder, CO 80309-0392 United States
AU: Toon, O B
EM: btoon@lasp.colorado.edu
AF: Program in Atmospheric and Oceanic Sciences, University of Colorado at Boulder, UCB 311, Boulder, CO 80309-0311 United States
AU: Tolbert, M A
EM: tolbert@spot.colorado.edu
AF: Department of Chemistry and Biochemistry and CIRES, University of Colorado at Boulder, UCB 216 CIRES 318, Boulder, CO 80309-0216 United States
AB: An organic haze layer in the upper atmosphere of Titan plays a crucial role in the atmospheric composition and climate of that moon. Such a haze layer may also have existed on the early Earth, providing a UV shield for greenhouse gases needed to warm the planet enough for life to arise and evolve. Despite the implications of such a haze layer, little is known about the organic material produced under early Earth conditions when both CO2 and CH4 may have been abundant in the atmosphere. We have developed a method by which we can analyze the aerosol products in real time, using an Aerosol Mass Spectrometer (AMS) to study the chemical composition and size of particles as a function of trace gas composition. We use a deuterium lamp with a spectral range from 115 - 400 nm to produce particles from gaseous mixtures of CH4/CO2/N2, thus simulating the low ultraviolet wavelengths available to the early Earth's atmosphere. Ongoing studies explore the chemical and physical properties of these aerosols as function of C/O ratio and other experimental parameters such as total pressure. The properties of the haze aerosols formed using the UV lamp are also compared to those from previous studies using an electrical discharge source.
DE: 0305 Aerosols and particles (0345, 4801)
DE: 0325 Evolution of the atmosphere
DE: 0343 Planetary atmospheres (5405, 5407, 5409, 5704, 5705, 5707)
SC: Volcanology, Geochemistry, Petrology [V]
MN: 2004 AGU Fall Meeting