NASA Quarterly
UVIS
Q2 - 2014
(February – April 2014)
Quarterly
1
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UVIS: Science Highlights
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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: 750-800 km and 400-500 km ranges. This figure
shows the latitude and longitude coverage for the 13 UVIS observations which satisfy the quality control criteria.
Quarterly
2
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UVIS: Science Highlights
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Quarterly
3
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.
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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
4
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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 mission
172
• Presentations at scientific conferences (Feb - Apr 2014)
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2 presentations at EGU, Vienna, Austria, April 28- May 2 (Esposito, Colwell)
• Public Outreach and Press Activities (Feb – Apr 2014)
–
–
–
Quarterly
0: public talks
0: press releases
0: press conferences (phone interviews)
5
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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
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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)
Quarterly
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1 paper in review at ApJS
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1 papers in press in Discoveries of Modern Science
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1 papers in review in GRL
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1 paper in press and 4 in review in Icarus
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1 paper in press and 1 in review in JGR
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1 paper in press in J. Mol. Spectrosc.
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1 chapter in press in the book Titan: Surface, Atmosphere and Magnetosphere
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1 paper in review in SSR
6
13
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UVIS: Plans
Continued from last page
–Upcoming presentations at scientific conferences (May – Jul 2014)
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None this quarter
–Public Outreach and Press Activities (May – Jul 2014)
Quarterly
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0: public talks
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0: press releases
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0: press conference (phone interview)
7
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Backup Material
Quarterly
8
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UVIS: Publications – 2014 (Nov 2013 – Apr 2014)
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Esposito, L.W. 2014. 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. 2014. Composition of Titan's Upper Atmosphere from
Cassini UVIS EUV Stellar Occultations. Planet. Space Sci. 88 86-92. (Published Nov. 2013, but found March
2014.)
•
Li, C., X. Zhang, J.A. Kammer, M.-C. Liang, R-L. Shia, Y.L. Yung. 2014. 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. 2014. 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
9
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UVIS: Publications (In Press)
•
Esposito, L.W.E. 2014. 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. 2014. 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. 2014.
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. 2014. 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. 2014. 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
10
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UVIS: Publications (Submitted)
•
Carbary, J., D. Mitchell, and W. Pryor. 2014. 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. 2014. 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. 2014. 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. 2014. The high resolution EUV spectrum of N2 by
electron impact. ApJS (Submitted Nov 29, 2013)
•
Hendrix, A.R. Shemansky, D.E. et al. 2014. Io: FUV and EUV Spectroscopy from Cassini. Icarus. (Planned to
submit in October 2013)
•
Kempf, S., et al. 2014. Enceladus as an active body. SSR. (Submitted March 3, 2014).
•
Lavvas, P., West, R.A., and Gronoff, G.. 2014. 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. 2014. Injection, Interchange And Reconnection: Energetic
Particle Observations In Saturn's Magnetotail. JGR. (Submitted August 15, 2013, but didn’t know last quarter)
Quarterly
11
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UVIS: Science Presentations – Q1-2014 (Feb – Apr 2014)
– EGU, Vienna Austria, April 28 – May 2
Quarterly
•
Esposito: UV Imaging Spectroscopy of the Saturn System
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Colwell: Abundance of small particles in Saturn’s rings from Cassini UVIS and VIMS stellar
occultations.
12
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UVIS: Outreach – Q1-2014 (Feb – Apr 2014)
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EPO: Talks to school children, teachers and public
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Press releases
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None this quarter
None this quarter
Press conferences & interviews
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None this quarter
Quarterly
13
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