1. Jet Propulsion Lab, California Institute of Technology*
07/16/96
Titan Haze
Robert West
Jet Propulsion Lab, California Institute of Technology
25-Jul-05 *

2. Pioneer and Voyager Measurements*
07/16/96
Pioneer and Voyager Measurements
West and Smith Icarus 90 (1991) *

3. Fractal Aggregates High-dimension Cluster-cluster Low-dimension*
07/16/96
Fractal Aggregates
Cluster-cluster
aggregate
High-dimension
aggregate
Low-dimension
aggregate
M. Lemmon
Dissertation *

4. Summary for Titan Aggregates*
07/16/96
Summary for Titan Aggregates
Fractal aggregate models naturally account for Titan’s strong polarization and modest forward scattering
Early models called for few (~10) monomers, more recent models by Lemmon and by Rannou et al. have more but always the monomer radius is near 0.06 μm.
Early Huygens DISR in situ results favor rmon = 0.05 μm; photometry calls for more sophisticated model. *

5. *
07/16/96
UVIS Contributions
Kris Larsen, Yuk Yung, Dane Tice, Don Shemansky, Ian Stewart and others
Image cubes from EUVFUV observations
Stellar occultation profiles
Riders with other instruments *

6. *
07/16/96 *

7. UVIS Contributions, Cont.*
07/16/96
UVIS Contributions, Cont.
UVIS Samples Highest haze levels
UVIS is sensitive to the small end of the particle size distribution. The phase behavior provides information on particle sizes
UVIS constrains refractive index below 190 nm
Detached haze layer can be seen in stellar occultation data but is below the resolution of EUVFUV
Vertical haze profiling may be available from stellar occultations (possible confusion with gaseous constituents?)
Acetylene is present in the reflected sunlight spectrum *

8. Near-term plan I. Data Reduction*
07/16/96
Near-term plan
I. Data Reduction
Kris Larsen provides image cubes with geometry
II. Modeling (West, Larsen, Yung, Tice)
Currently testing spherical-shell intensity code (JPL) against pseudo spherical-shell code (Y. Yung and D. Tice, Caltech)
Need a model to relate a physical particle (e.g. aggregates) to optical properties (Mackowski and Mishchenko)
Run a suite of models for various size parameters, refractive indices and vertical profiles and compare with data (UVIS and ISS).
Multi-components and/or vertical structure may be required *