DPS Meeting Oct 8 2010

Tholins in the Upper Atmosphere of TitanYuk Yung (Caltech)X. Zhang (Caltech)M. C. Liang (Academia Sinica, Taiwan)D. E. Shemansky (Space Environment Technologies)

P36.08 Vertical Structure Of The Titan Atmosphere From Cassini UVIS ObservationsP11.11 Aerosol Heating in the Stratosphere of Jupiter

Lorenz + Mitton 2002

Solar Scattering

Stellar Occultation

J. Ajello

UVIS spectrum

Liang et al. 2007

tholin

CH4

Impact: 514 km

Stellar Occultation

• Calibration

• Scattered light : Shemansky et al. 2009

• Calibration : 3-15-02 Rept by UVIS Team

Qe =−4xI (m2 −1m2 + 2

)

Qs =83x4 m2 −1

m2 + 2

2

x =2πrλ Single Scattering Albedo

(SSA):

SSA = Qs/Qe

Important Parameters

Goody and Yung 1989

Obs: 0.118

16 nm

Mie code calculationRefractive Index from Khare and Sagan (1984)

SSA at 1875 Å

Shemansky et al. 2010

. 2Trainer, et al 2006

Tomasko et al. 2008: ~100 km 50 nm radius 3000 monmers

Comparisons

• Tholin Radius at 1040 km: 16 nm Liang et al. (2007) “guessed” 12.5

nm from Stellar Occultation only

• Comparable to 25 nm (in radius) from Trainer et al. (2006)

• Source of monomers at ~100 km from Tomasko et al. (2008)

Summary

Thanks

• Cassini UVIS (PI Esposito)

• PATM (Phil Crane)

• OPR (Curt Niebur)