NASA Quarterly
UVIS
Q3 - 2014
(May – July 2014)
Quarterly
1
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UVIS: Science Highlights
Europa model
atmosphere based on
the Liang et al. (2005)
model for Callisto, in
which the CO2 source
is suppressed to reflect
conditions at the
surface of Europa. The
legend identifies the
species in the plot, O I,
H I, O II, O2, and O+.
Tholin Distributions in the Atmosphere of Titan
Graduate student Joshua Kammer continues to make progress in analyzing the stellar occultation data from
Cassini/UVIS instrument, based on a global inversion using the method of optimal retrieval.
We built a Europa atmosphere model based on the Liang et al. (2005) model for Callisto, in which the CO 2 source is
suppressed to reflect conditions at the surface of Europa. The oxygen in this model is derived from H 2O extracted
from the surface cold, with recycling, leaving a cold O I atmosphere. This new model of Europa (see Fig. 1) supports
the recent analysis of UVIS observations of Europa during the Jupiter flyby. The analysis of observations is
consistent with the UV model (see Fig. 2 of Shemansky et al. (2014)) in that O rather than O 2 is the major constituent
of the atmosphere. (Yung)
Quarterly
2
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UVIS: Science Highlights
Particle sizes and clumps in the A
ring from UVIS stellar
occultations
This scatter plot shows that different
regions of the A ring have
different size scales for particles
and/or clumps. If all regions were
the same, then all the points
would lie on a single curve.
Different regions, identified by
color, lie on distinctly different
curves reflecting differences in
their particle populations.
(Colwell)
Quarterly
3
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UVIS: Science Highlights
Particle sizes and clumps in the
Cassini Division from UVIS
stellar occultations
This scatter plot shows that different
regions of the Cassini Division
have different size scales for
particles and/or clumps. If all
regions were the same, then all
the points would lie on a single
curve. Different regions, identified
by color, lie on distinctly different
curves reflecting differences in
their particle populations.
(Colwell)
Quarterly
4
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UVIS: Science Highlights
Four UVIS Team meetings at DLR in Berlin.
• Clockwise from top left: 1997, 2005, 2009, 2014
Quarterly
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UVIS: Accomplishments
Science Highlights (from this quarter: May – Jul 2014)
–
Bradley: Identified Carbon III spectral line in EUV spectra of the rings that may be used as a
reflectance data point for ring spectroscopic analysis. Currently converting to I/F.
– Bradley: Determined that one reason why Hapke and Shkuratov modeling of the ring composition
were giving such different results is that Hapke model does not utilize ring particle phase function.
This implies that rings cannot be spectroscopically modeled as a flat surface covered by a regolith,
but instead need to be treated as a complex clumpy surface covered by regolith.
–
Bradley: Uploaded a new version of cube generator to UVIS team website. New version has a fix for
a case sensitive issue that some members were encountering.
–
Hendrix: Refined composite spectra (UVIS + HST + ISS) of Enceladus and Tethys to understand
contributions from, and effects of, Enceladus plume deposits, E-ring grains and radiolysis.
Quarterly
6
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UVIS: Accomplishments
• Publications
–
–
–
–
–
Published this quarter (May – Jul 2014)
1
In press (Went into press May – Jul 2014, also includes still in press from earlier quarters)
2
Submitted (Submitted May – Jul 2014, also includes submitted earlier and still in review)
13
Published 2014 to date (since Nov 2013)
9
Published entire mission
179
• Presentations at scientific conferences (May – Jul 2014)
–
–
2 presentations at EGU, Vienna, Austria, April 28 - May 2 (Esposito, Colwell)
3 presentations at the Europa Plume Workshop, APL, June 2 (Esposito, Hansen, Hendrix)
• Public Outreach and Press Activities (May – Jul 2014)
–
–
–
Quarterly
3: public talks
0: press releases
0: press conferences (phone interviews)
7
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UVIS: Plans
– Science Plans (Aug – Oct 2014)
Quarterly
•
Bradley: Investigate EUV spectra of Saturn’s rings.
•
Bradley: Compare Saturn ring spectra with Saturn icy moon spectra.
•
Bradley: Continue investigation of ring particle albedo by generating albedos at many more wavelengths than before. Compositional
modeling of ring particles using ring particle albedo and optical constants of candidate materials.
•
Bradley: Combine EUV Carbon III line in EUV with FUV spectra to extend spectroscopic modeling down into the EUV.
•
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.
•
Colwell: Trying to get the ring occultation statistics analysis written up and submitted.
•
Colwell: Writing paper on self-gravity wakes using UVIS and VIMS data.
•
Colwell: Starting work on differential optical depth with UVIS/VIMS/RSS data.
•
Colwell: Submit CDAP proposal on particle size distributions.
•
Colwell: Analysis of stellar diffraction signals with Becker.
•
Hendrix: Refine UVIS icy priorities in FPROX.
•
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.
•
Yung: A photochemistry-transport will be developed to fully account for the interaction between the atmosphere of Io and the
magnetosphere.
8
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UVIS: Plans
– Publications (Aug – Oct 2014) In preparation (includes submitted, but not yet published)
Quarterly
•
1 paper in press in Discoveries of Modern Science
•
1 paper in review in GRL
•
1 paper in press and 9 in review in Icarus
•
1 paper in review in JGR
•
1 paper in review in Science
•
1 paper in review in SSR
9
16
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UVIS: Plans
Continued from last page
–Upcoming presentations at scientific conferences (Aug – Oct 2014)
•
2 presentations at COSPAR, August 2-10, Moscow (Esposito: 2)
•
7 presentations at Planetary Rings Workshop, Aug 13-15, Boulder, CO (Albers, Becker, Bradley,
Colwell, Cuzzi, Esposito, Stewart)
•
3 presentations at EPSC, September 2014, Portugal. (Albers, Becker, Colwell)
–Public Outreach and Press Activities (Aug – Oct 2014)
Quarterly
•
0: public talks
•
1: press release (Hendrix: Finalize Tethys nugget—currently in iteration with Mary Beth Murrill at
JPL)
•
0: press conference (phone interview)
10
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Backup Material
Quarterly
11
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UVIS: Publications – 2014 (Nov 2013 – Jul 2014)
•
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 232, 157-175, doi:10.1016/j.icarus.2013.12.027. (Published
January 2014)
•
Esposito, L.W. 2014. Planetary Rings. A post-equinox view. Cambridge, UK: Cambridge University Press,. (Published
March 2014)
•
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, 211:28 (27pp). (Published April 2, 2014)
•
Jasinski, J. M., Arridge, C. S., Lamy, L., Leisner, J. S., Thomsen, M. F., Mitchell, D. G., Coates, A. J., Radioti, A.,
Jones, G. H., Roussos, E., Krupp, N., Grodent, D., Dougherty, M. K., Waite, J. H. 2014. Cusp observation at Saturn’s highlatitude magnetosphere by the Cassini spacecraft. GRL. 41, 5, 1382-1388. (Published March 16. 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)
•
Li, C., X. Zhang, J.A. Kammer, M.-C. Liang, R-L. Shia, Y.L. Yung. 2013. A non-monotonic eddy diffusivity profile of Titan's
atmosphere revealed by Cassini observations. Planet. Space Sci. DOI: 10.1016/j.pss.2013.10.009 (Available online
11/23/13)
•
Nichols, J. D., S. V.Badman, K. H. Baines, R. H. Brown, E. J. Bunce, J. T. Clarke, S. W. H. Cowley, F. J. Crary, M. K.
Dougherty, J.-C. Gérard, A. Grocott, D. Grodent, W. S. Kurth, H. Melin, D. G. Mitchell, W. R. Pryor and T. S. Stallard. 2014.
Dynamic auroral storms on Saturn as observed by the Hubble Space Telescope, GRL. 41, 10, 3323-3330. (Published May
2014)
•
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. 227, 152-175, doi:10.1016/j.icarus.2013.09.002. (Published January 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
12
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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)
•
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)
Quarterly
13
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UVIS: Publications (Submitted)
•
Badman S., G. Provan, E. Bunce, D.G Mitchell, Henrik Melin, S.W. Cowley, A.Radioti, W. Kurth, W. Pryor, J.D
Nichols, S.L Jinks, T.S Stallard, R.H Brown, K.H Baines, M.K Dougherty. 2014. Saturn's auroral morphology and
field-aligned currents during a solar wind compression. Icarus special issue. (Submitted June 2014 )
•
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)
•
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.)
•
Melin, H., et al. [Pryor]. 2014. Simultaneous multi-scale and multi-instrument observations of Saturn's aurorae
during the 2013 observing campaign. Icarus. (submitted Q3 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)
•
Mitchell D., J. F. Carbary, E. J. Bunce, A. Radioti, S.V. Badman, W. R. Pryor, G. B. Hospodarsky, W. S. Kurth.
2014. Recurrent pulsations in Saturn's high latitude magnetosphere. Icarus. (Submitted 5/14).
•
Pilorz, S., N. Altobelli, J. E. Colwell, and M. Showalter 2014. Thermal Transport in Saturn’s B Ring Inferred from
Cassini CIRS. Icarus (submitted Q3 2014).
Continued…
Quarterly
14
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UVIS: Publications (Submitted)
•
Radioti A., D. Grodent, X. Jia, J.-C. Gérard, B. Bonfond, W. Pryor, J. Gustin, D. Mitchell, C.M. Jackman, 2014. A
remarkable magnetotail reconnection event at Saturn as observed by UVIS/Cassini. Icarus special issue
(Submitted May 2014).
•
Radioti A., D. Grodent, J.-C. Gérard, S. E. Milan, R.C. Fear, C.M. Jackman B. Bonfond, W. Pryor. 2014. Saturn’s
elusive transpolar arc. GRL. (Submitted November 2013)
•
Royer, E.M. and Hendrix, A.R. 2014. First far-ultraviolet disk-integrated phase curve analysis of Mimas, Tethys
and Dione from the Cassini-UVIS data sets, Icarus (Submitted March 19, 2014)
•
Shemansky, Y. L. Yung, X. Liu, J. Yoshii, C. J. Hansen, A. R. Hendrix and L.W.Esposito. 2014. The state of the
plasma sheet at Europa is incompatible with large local mass loading from a geophysically active source. Science.
(Submitted July 3, 2014)
•
Stevens, M., Evans, S., Lumpe, J. Westlake, J.H., Ajello, J.M., Bradley, T., Esposito, L.W. 2014. Molecular
Nitrogen and Methane Density Retrievals from Cassini UVIS Dayglow Observations of Titan's Upper Atmosphere.
Icarus. (Submitted April 7 2014)
Quarterly
15
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UVIS: Science Presentations – Q3-2014 (May – Jul 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.
– Europa Plume Workshop, APL, June 2
Quarterly
•
Esposito: Structure and composition
•
Hansen: Cassini Europa Data Analysis for Plume Search
•
Hendrix: Lessons learned at Enceladus for application at Europa
16
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UVIS: Outreach – Q3-2014 (May – Jul 2014)
•
•
EPO: Talks to school children, teachers and public
–
Hansen: Cassini at Saturn After-school group, Dixie High School, St. George, UT, May 6.
–
Colwell: Running Rings Around Saturn, Winter Park Public Library, Winter Park Florida, July 9, 2014
–
Hendrix: Ultraviolet Spectroscopy of Solar System Moons, Seminar at Freie Universitaet, Berlin, June 19
Press releases
–
•
None this quarter
Press conferences & interviews
–
None this quarter
Quarterly
17
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