From: IN%"W.K.Tobiska@jpl.nasa.gov" "W Kent Tobiska" 6-NOV-1997 12:03:07.51 To: IN%"simmons@pisces.colorado.edu" CC: IN%"ktobiska@glvax0.jpl.nasa.gov" Subj: E11 OAP text (remove the MWG section) Subject: E11 OAP text Author: wsweet@mail1.jpl.nasa.gov at Internet Date: 10/20/97 3:44 PM MWG --- The highest priority UVS magnetospheric observations in E11 are real-time Io torus midnight ansa measurements (11MANS01-02-03) performed inbound to Jupiter in conjunction with EUV, when both are pointed at 90 deg cone angle. They are designed to obtain S and O ion emission line strengths at EUV as well as FUV (115-320 nm) and NUV (280-430 nm) wavelengths. Intensity ratios will determine electron temperatures, and integrated intensity characterizes the torus energy output for energy budget considerations. Other simultaneous UVS/EUV goals include two midnight ansa profiles (11MPRO01-02: UVS observes ansa at >90 deg cone angle, while EUV views the cold inner torus) and two Jupiter northern aurora observations (11AURA01-02: UVS at ~90 deg). A final observation of the cold torus occurs with EUV (11MPRO04) before it is shut off at 17.0 Rj (closest operation in the prime mission, although it is intended to be operated to 17 Rj in GEM). Although not simultaneous with EUV, UVS observations of the noon ansa of the Io torus (11NANS11-12-02-03) are also performed inbound to Jupiter. In addition, a search (CTORUS01) for FUV neutral emissions from H and O in the vicinity of the Callisto orbit ansa, is made early in E11A at >90 deg cone angle. Finally, two 3-hour observations (GRATNG01-02) of interplanetary Lyman- alpha emissions occur in E11B; they are designed to monitor the performance of the UVS grating. AWG --- The top priority UVS Jupiter atmospheric observation during E11 is a recorded and realtime far-ultraviolet Lyman-alpha (121 nm) observation of the northern aurora (AURVAR01,02,03). With this observation using the G-detector, we will obtain the best spatial and temporal detail in Lyman-alpha of the Jovian aurora from the darkside during the mission. SSI will observe near the 180 longitude immediately before and after this observation which covers the same longitude region for the UVS. NIMS rides along with UVS for this observation. We expect to observe the footprint of the Io fluxtube and any potential emission from a Europa fluxtube footprint if it exists above the limits of our detectability. Another unique, high priority recorded observation is the H limb brightening/darkening and H corona to be obtained in an equatorial region Lyman-alpha scan (EWMAPS01). This observation is similar to one done in C10 and should provide a second dataset to definitively map the H corona. A FUV brown barge observation set will be obtained in the feature track campaign (FTKR1Exy) for one rotation at 3 emission angles. Analysis of these data will result in a unique data set of stratospheric aerosol scattering properties surrounding this feature over different emission angles. The brown barge data will be taken immediately following the SSI multi-color images as well as coincident with the NIMS data. Global mapping of equatorial H Lyman-alpha on the darkside will continue as in previous orbits to obtain hydrogen distribution maps without the influence of direct solar radiation (DRKMAP01-02). The southern aurora will be mapped by the color ratios for H2 bands which help determine precipitating particle energies (AURMAP01). Finally, the mapping of hydrocarbons at four latitude bands will occur (BRTMAP01) to compare with previous observations as part of the study of long-term changes to stratospheric absorbers. SWG --- In C10, UVS will continue to observe Europa, Ganymede, Callisto and Io at various phase angles and longitudes. Along with complementary measurements of satellite albedos and emission obtained in other orbits, these observations contribute to the UV phase function curves for the Galilean satellites. UVS observes Callisto (CUPHASXX) at the following phase angles (and longitudes): 89 deg (100 deg), 70 deg (100 deg), and 61 deg (90 deg). EUPHAS65 and EUPHAS64 observe Europa at 65 deg phase (135 deg) and 64 deg phase (139 deg), respectively. Ganymede is observed at 21 deg phase (350 deg) in GUPHAS21 and 0 deg phase (342 deg) in GUPHAS00. IUPHAS113 observes Io at 113 deg phase (112 deg). Continuing its eclipse campaign, UVS observes each Galilean satellite in eclipse (XXDARK). Analysis of eclipse data sets will be used with similar observations in other orbits to provide the morphology of the satellite's atmospheres in the presence and absence of direct sunlight. UVS observes Callisto twice near the eclipse umbra, once looking for the OH- with the N-channel (309.0 nm) and again with the G-channel to look for oxygen (135.6 nm). Europa is view twice near the eclipse umbra, both observations looking for oxygen (135.6 nm) and sulfur (147.9 nm) with the G-channel. Ganymede is observed twice near eclipse umbra, the first observation looking for OH- (309.0 nm) with the F-channel and the second observation looking for oxygen (135.6 nm). UVS also observes Io near eclipse umbra, looking for oxygen (135.6 nm) and sulfur (147.9 nm) with the G-channel. UVS has two Europa closest approach observations planned. EUEUDISK targets Europa at 12 locations with F-channel full scans to determine high spatial resolution albedos. EULEAD observes Europa's leading hemisphere's albedo at four latitudes (60 deg N, 30 deg N, 0 deg, 30 deg S) with F-channel full scans. Finally, UVS plans ridealong observations performed in conjunction with NIMS in order to supplement and complement NIMS satellite surface property measurements. EUM20HR (20 hours from closest approach), EUP17HR (17 hours from closest approach), EUM15HR (15 hours from closest approach), EUDRKLIT (dark mosaic of crater), EURORT (real-time), EUCYCLOD (cyclodal) are high-resolution Europa observations at 160 to 320 nm. UVS will also performs NIMS ridealong measurements of Io in IUHRSPEC in the same wavelength region. Wendy