HR: 0800h
AN: P11C-0701    [Abstracts]
TI: Optical Properties of Early Earth and Titan Haze Laboratory Analogs in the Mid-Visible
AU: * Hasenkopf, C A
EM: Christa.Hasenkopf@colorado.edu
AF: Department of Atmospheric & Oceanic Sciences, UCB 311, University of Colorado, Boulder, CO 80309-0311, United States
AU: * Hasenkopf, C A
EM: Christa.Hasenkopf@colorado.edu
AF: Cooperative Institute for Research in Environmental Sciences, 216 UCB, University of Colorado, Boulder, CO 80309-0216, United States
AU: Beaver, M R
EM: Melinda.Beaver@colorado.edu
AF: Cooperative Institute for Research in Environmental Sciences, 216 UCB, University of Colorado, Boulder, CO 80309-0216, United States
AU: Beaver, M R
EM: Melinda.Beaver@colorado.edu
AF: Department of Chemistry and Biochemistry, UCB 215, University of Colorado, Boulder, CO 80309-0215, United States
AU: Dewitt, H L
AF: Cooperative Institute for Research in Environmental Sciences, 216 UCB, University of Colorado, Boulder, CO 80309-0216, United States
AU: Dewitt, H L
AF: Department of Chemistry and Biochemistry, UCB 215, University of Colorado, Boulder, CO 80309-0215, United States
AU: Tolbert, M
EM: tolbert@cires.colorado.edu
AF: Cooperative Institute for Research in Environmental Sciences, 216 UCB, University of Colorado, Boulder, CO 80309-0216, United States
AU: Tolbert, M
EM: tolbert@cires.colorado.edu
AF: Department of Chemistry and Biochemistry, UCB 215, University of Colorado, Boulder, CO 80309-0215, United States
AU: Toon, O B
EM: Brian.Toon@lasp.colorado.edu
AF: Department of Atmospheric & Oceanic Sciences, UCB 311, University of Colorado, Boulder, CO 80309-0311, United States
AU: Toon, O B
EM: Brian.Toon@lasp.colorado.edu
AF: Laboratory for Atmospheric and Space Physics, 1234 Innovation Drive, 80303-7814, CO 80303-7814, United States
AU: McKay, C
EM: cmckay@mail.arc.nasa.gov
AF: Space Sciences Division, NASA Ames Research Center, Moffett Field, CA 94035, United States
AB: An organic haze layer, similar to the thick haze currently enveloping Titan, may have formed on early Earth. This haze could have had profound effects on the early Earth climate and the life existing and evolving on it. Climate models of early Earth that include this organic haze have had to rely on optical properties of Titan's haze. However, unlike Titan haze, early Earth organic haze likely formed in an atmosphere containing the oxidizer CO₂ in addition to CH₄ and N₂. The presence of CO₂ causes oxygen-incorporation into the haze aerosol. We investigate the differences in the chemical and optical properties between Titan and early Earth haze laboratory analogs that this oxygen-incorporation induces via the novel technique of cavity ring-down aerosol extinction spectroscopy at λ = 532nm. This technique allows the extinction of size-selected aerosols to be measured "on the fly," which is unprecedented for Titan or early Earth haze laboratory analog studies. Using the measured extinction values and applying Mie theory, we estimate a total refractive index at λ = 532nm of n = 1.55±0.05 and k = 0.025±0.005 for a Titan haze analog and compare our results to other workers who have used thin-film techniques. Studies of early Earth organic haze are ongoing. These experiments provide essential data for modeling early Earth's climate and understanding the conditions that early life experienced.
DE: 5210 Planetary atmospheres, clouds, and hazes (0343)
DE: 5225 Early environment of Earth
DE: 5400 PLANETARY SCIENCES: SOLID SURFACE PLANETS
DE: 6281 Titan
SC: Planetary Sciences [P]
MN: 2007 Fall Meeting