Quarterly 1 NASA Quarterly UVIS Q (February – April 2014)

Quarterly 2 UVIS: Science Highlights CalTech Graduate student Joshua Kammer is analyzing the Titan stellar occultation data from Cassini/UVIS instrument. The mean optical depth as a function of line of sight impact parameter is derived for the spectral range between 1700 and 1900 A from four stellar occultations. Vertical profiles of tholin particles above ~300 km are then retrieved. The profiles show two depletion regions: km and km ranges. This figure shows the latitude and longitude coverage for the 13 UVIS observations which satisfy the quality control criteria.

Quarterly 3 UVIS: Science Highlights Occultation T53: In the upper right is a model fit to the data. This model is derived from a 'density' profile shown in the upper left. This 'density' is a combined effect from both number density of particles and the particle cross-section at each altitude, and is normalized to the value at the surface. Most important to note are the regions of transition from a smooth exponential function of altitude to 'depleted' layers or gaps in density, though this is likely also revealing a change in optical properties of the aerosols at around 500 and 750 km. The two lower panels show the line of sight optical depth of the model on the lower right, and the vertical optical depth from the top of the atmosphere on the lower right for comparison.

Quarterly 4 UVIS: Science Highlights NASA trained several pairs of eyes on Saturn including NASA's Hubble Space Telescope and Cassini UVIS. "This is our best look yet at the rapidly changing patterns of auroral emission," said Wayne Pryor, a Cassini co-investigator at Central Arizona College in Coolidge, Ariz. "Some bright spots come and go from image to image. Other bright features persist and rotate around the pole, but at a rate slower than Saturn's rotation."

Quarterly 5 UVIS: Accomplishments Publications – Published this quarter (Feb – Apr 2014)2 – In press (Went into press Feb – Apr 2014, also includes still in press from earlier quarters)5 – Submitted (Submitted Feb – Apr 2014, also includes submitted earlier and still in review) 8 – Published 2014 to date (since Nov. 2013)4 – Published entire mission172 Presentations at scientific conferences (Feb - Apr 2014) – 2 presentations at EGU, Vienna, Austria, April 28- May 2 (Esposito, Colwell) Public Outreach and Press Activities (Feb – Apr 2014) – 0: public talks – 0: press releases – 0: press conferences (phone interviews)

Quarterly 6 UVIS: Plans – Science Plans (May – Jul 2014) Continue investigation of ring particle albedo. Compare Saturn ring spectra with Saturn icy moon spectra. Compositional modeling of ring particles using ring particle albedo and optical constants of candidate materials Investigate EUV spectra of Saturn’s rings Bradley: Compare Saturn ring spectra with Saturn icy moon spectra. Bradley: Compositional modeling of ring particles using ring particle albedo and optical constants of candidate materials. Colwell: Complete initial paper on stellar occultation statistics. Colwell: Continue work on new self-gravity wake model. Colwell: Work with Becker on diffraction modeling. Begin paper preparation. Colwell: Paper on faint and narrow rings is in production (student Bryce Bolin is lead author). Colwell: Paper on self-gravity wakes is in preparation (Colwell or Jerousek lead author). Colwell: Submit new and updated occultation data sets to the Planetary Data System. [still pending per Josh] Colwell: Paper on analysis of Rev 9 solar occ diffraction signal from F ring is in preparation (student Becker is lead author). Yung: UVIS spectra will be analyzed using a scattering radiative transfer code, including the spherical geometry involved in the Cassini observations. The gaseous absorptions used in the radiative model will be taken from previous papers by this group. Yung: We will continue the tholin analysis to provide a complete picture of the spatial and temporal distribution of tholins. – Publications (May – Jul 2014) In preparation (includes submitted, but not yet published) 13 1 paper in review at ApJS 1 papers in press in Discoveries of Modern Science 1 papers in review in GRL 1 paper in press and 4 in review in Icarus 1 paper in press and 1 in review in JGR 1 paper in press in J. Mol. Spectrosc. 1 chapter in press in the book Titan: Surface, Atmosphere and Magnetosphere 1 paper in review in SSR

Quarterly 7 UVIS: Plans Continued from last page – Upcoming presentations at scientific conferences (May – Jul 2014) None this quarter – Public Outreach and Press Activities (May – Jul 2014) 0: public talks 0: press releases 0: press conference (phone interview)

Quarterly 8 Backup Material

Quarterly 9 UVIS: Publications – 2014 (Nov 2013 – Apr 2014) Esposito, L.W Planetary Rings. A post-equinox view. Cambridge, UK: Cambridge University Press,. (Published March 2014) Kammer, J.A., D.E. Shemansky, X. Zhang, Y.L. Yung Composition of Titan's Upper Atmosphere from Cassini UVIS EUV Stellar Occultations. Planet. Space Sci (Published Nov. 2013, but found March 2014.) Li, C., X. Zhang, J.A. Kammer, M.-C. Liang, R-L. Shia, Y.L. Yung A non-monotonic eddy diffusivity profile of Titan's atmosphere revealed by Cassini observations. Planet. Space Sci. (Available online November 11, 2013, but found out March 28, 2014.) West, R., P. Lavvas, C. Anderson, and H. Imanaka Titan Haze. A chapter in Titan: Surface, Atmosphere and Magnetosphere. Eds. I. Mueller-Wodarg, C. Griffith, T. Cravens and E. Lellouch. Cambridge University Press (Cambridge Planetary Science Series). (Published February 23, 2014)

Quarterly 10 UVIS: Publications (In Press) Esposito, L.W.E Saturn’s Rings. Discoveries in Modern Science. (Went to press August 28, 2013) Gustin, J., J.C. Gerard, D. Grodent, G.R. Gladstone, J.T. Clarke, W.R. Pryor, V. Dols, B. Bonfond, A. Radioti, L. Lamy, J.M. Ajello Effects of methane on giant planet's UV emissions and implications for the auroral characteristics. J. Mol. Spectrosc. (Accepted. March 29, 2013.) Lamy, L., Prange, R. Pryor, W., Gustin, J. Badman, S., Melin, H. Stallard, T., Mitchell, D.G., Brandt, P.C Multi-spectral simulations diagnosis of Saturn’s aurorae throughout a planetary rotation. JGR-Space Physics. (Accepted June 17, 2013) Nicholson, P. D., R. G. French, M. M. Hedman, E. A. Marouf, and J. E. Colwell Noncircular Features in Saturn’s Rings I: The Edge of the B Ring. Icarus. (In press as of Sept 9, 2013) West, R., P. Lavvas, C. Anderson, and H. Imanaka Titan Haze. A chapter in Titan: Surface, Atmosphere and Magnetosphere. Eds. I. Mueller-Wodarg, C. Griffith, T. Cravens and E. Lellouch. Cambridge University Press [Cambridge Planetary Science Series]. (Accepted March 1, 2012)

Quarterly 11 UVIS: Publications (Submitted) Carbary, J., D. Mitchell, and W. Pryor Correlation of Saturn's Ultraviolet Aurora with Energetic Neutral Atoms. GRL. (Submitted June 28, 2012) Cuzzi, J. N., A. D. Whizin, R. C. Hogan, A. R. Dobrovolskis, L. Dones, M. R. Showalter, J. E. Colwell, and J. D. Scargle Saturn’s F Ring Core: Calm in the Midst of Chaos. Icarus (Submitted September 2013) Gustin, J., Moses, J., Gerard, J-C., and Grodent, D Saturn H2 density and temperature profiles at low, medium and high latitudes from Cassini UVIS solar occultations. Icarus. (Submitted on Dec. 3, 2013) Heays, A.N., Ajello, J.M., Aguilar, A., Lewis, B.R., Gibson, S.T The high resolution EUV spectrum of N 2 by electron impact. ApJS (Submitted Nov 29, 2013) Hendrix, A.R. Shemansky, D.E. et al Io: FUV and EUV Spectroscopy from Cassini. Icarus. (Planned to submit in October 2013) Kempf, S., et al Enceladus as an active body. SSR. (Submitted March 3, 2014). Lavvas, P., West, R.A., and Gronoff, G Titan’s emission processes during eclipse. Icarus. (March 28, 2014.) Mitchell, D.G., P. C. Brandt, J.F. Carbary, W.S. Kurth, S.M. Krimigis, C. Paranicas, N. Krupp, D.C. Hamilton, B.H. Mauk, G. B. Hospadarsky, M.K. Dougherty, W. R. Pryor Injection, Interchange And Reconnection: Energetic Particle Observations In Saturn's Magnetotail. JGR. (Submitted August 15, 2013, but didn’t know last quarter)

Quarterly 12 UVIS: Science Presentations – Q (Feb – Apr 2014) – EGU, Vienna Austria, April 28 – May 2 Esposito: UV Imaging Spectroscopy of the Saturn System Colwell: Abundance of small particles in Saturn’s rings from Cassini UVIS and VIMS stellar occultations.

Quarterly 13 UVIS: Outreach – Q (Feb – Apr 2014) EPO: Talks to school children, teachers and public – None this quarter Press releases – None this quarter Press conferences & interviews – None this quarter