From: IN%"KTOBISKA@gllsvc.jpl.nasa.gov" 24-APR-1997 21:09:49.87 To: IN%"SIMMONS@pisces.colorado.edu" CC: IN%"KTOBISKA@gllsvc.jpl.nasa.gov" Subj: C3A UVS/EUV science summary Return-path: Received: from glvax0.jpl.nasa.gov by pisces.colorado.edu (PMDF V4.2-13 #12962) id <01II3J1VH4UO9PLUFM@pisces.colorado.edu>; Thu, 24 Apr 1997 21:09:33 GMT Date: Thu, 24 Apr 1997 14:09:50 -0700 From: KTOBISKA@gllsvc.jpl.nasa.gov Subject: C3A UVS/EUV science summary To: SIMMONS@pisces.colorado.edu Cc: KTOBISKA@gllsvc.jpl.nasa.gov Message-id: <970424140950.21e026e8@gllsvc.jpl.nasa.gov> Content-transfer-encoding: 7BIT From: Keith.L.Naviaux@ccmail.jpl.nasa.gov Message-Id: <950306105315.CC4612122@CCMail.Jpl.Nasa.Gov> Date: 06 Mar 95 10:50:00 -10109 To: tzmartin@gllsvc.jpl.nasa.gov, ajello@gllsvc.jpl.nasa.gov, sedberg@gllsvc.jpl.nasa.gov, ktobiska@gllsvc.jpl.nasa.gov, stewart@pisces.colorado.edu, simmons@pisces.colorado.edu, Keith.L.Naviaux@ccmail.jpl.nasa.gov, Brian.G.Paczkowski@ccmail.jpl.nasa.gov, Alicia.R.Allbaugh@ccmail.jpl.nasa.gov Subject: C3 UVS Science Summaries (AWG/MWG/SWG) Hello Terry, I know this is a bit late in getting to you, but I thought you'd still like to see it. Let me know if you have any questions or comments. Keith..... ***************************************************************************** UVS C3 SCIENCE SUMMARIES BY WORKING GROUP 3/6/95 UVS AWG: The top priority UVS Jupiter atmospheric observation during this orbit will be a recorded ultraviolet (115-410 nm) darkside map (DRKNEW) which is not possible to obtain from Earth. This observation during solar occultation will measure the planetary distribution of hydrogen (Balmer series and H2 continuum emissions) to distinguish hemispheric and longitudinal asymmetries with high spatial resolution. Analysis of the data will provide unique information on the energetics of the upper atmosphere without direct solar illumination. A major series of investigations will be the FUV/MUV (115-320 nm) contribution to the AWG feature track campaign. A white oval will be observed at two solar phase angles and three emission angles in realtime mode (FTKR1A/FTKR2A). The northern auroral zone (FTKR2B) will also be observed in the FUV/MUV almost coincident in time with MWG magnetospheric observations of field lines and particles connecting to the auroral region to be studied. Other realtime atmospheric observations will provide darkside equatorial hydrogen bulge (Lyman-alpha emission) mapping (FIXLON/ DRKMAP), and a star calibration on Spica (DRKMAP). Realtime southern auroral full spectral FUV observations (AURMAP) will provide dayside/nightside asymmetries for an analysis of color ratios. These ratios will provide the energies of the electrons precipitating into the auroral zone. A realtime, fixed local time FUV map of the equatorial brightside (FIXTMB) during one Jupiter rotation will provide information on local time variability of the upper atmosphere as well as long-term variability when combined with observations in other orbits. UVS MWG: The highest priority UVS magnetospheric observations during this orbit will be those in conjunction with the EUV instrument for the observations of the Io torus and Jupiter aurora. There are two general segments of the torus observations, one set for the C3 inbound torus measurements at the beginning of the C3A encounter period and the second set for the E4 inbound measurements at the end of the C3C cruise period. Both sets of realtime torus measurements (C3NPRO and E4MANS/E4MPRO/E4NANS) will map the torus ansae simultaneously with the EUV in S and O ion emission lines using the FUV/MUV wavelengths. Ratios of the emission lines will determine electron temperatures. The profile measurements, in particular, will characterize the torus ansae as a function of longitude, time, and radius. The realtime auroral measurements (E4AURA) will map the aurora and electroglow simultaneously with the EUV in the H2 bands. The integrated intensities will characterize the global energy output and the latitudinal and time variation of energetic particles input into the atmosphere. UVS SWG: In this orbit, the highest priority UVS satellite observations will be the recorded bright and dark limb tenuous atmosphere measurements of Callisto (BRTLMB and DRKLMB). These observations are designed to uniquely measure the altitudinal distribution of volatiles from their spectral signatures in the UV (OH: 301-312 nm) and FUV (H: Lyman-alpha), respectively. Two full spectrum MUV recorded ridealong observations with NIMS will observe surface scattering properties of the Asgard Crater (ASGARD) and the Asgard Ring structures (ARINGS). Realtime Europa and Ganymede full spectral FUV phase angle observations (EUPHAS and GUPHAS), not obtainable from Earth (Europa phases 68 and 40 degrees, Ganymede phase 80 degrees), will complement NIMS surface property measurements. Realtime Io and Europa eclipse full spectral FUV/MUV observations (IECLPS and EECLPS) will characterize airglow emissions as Io and Europa enter and exit eclipse. Analysis of these data will provide the morphology of Io's and Europa's atmospheres in the presence and absence of direct sunlight. An Io neutral cloud realtime observation (NTRLCL) will provide information on the composition and time variation of neutral constituents that produce this cloud to assist in modeling the Io plasma torus and Io atmosphere.