From: IN%"KTOBISKA@gllsvc.jpl.nasa.gov" 24-APR-1997 21:07:42.74 To: IN%"SIMMONS@pisces.colorado.edu" CC: IN%"KTOBISKA@gllsvc.jpl.nasa.gov" Subj: G2A UVS/EUV science summary Return-path: Received: from glvax0.jpl.nasa.gov by pisces.colorado.edu (PMDF V4.2-13 #12962) id <01II3IZA1YE89PLUQ8@pisces.colorado.edu>; Thu, 24 Apr 1997 21:07:27 GMT Date: Thu, 24 Apr 1997 14:07:44 -0700 From: KTOBISKA@gllsvc.jpl.nasa.gov Subject: G2A UVS/EUV science summary To: SIMMONS@pisces.colorado.edu Cc: KTOBISKA@gllsvc.jpl.nasa.gov Message-id: <970424140744.21e026e8@gllsvc.jpl.nasa.gov> Content-transfer-encoding: 7BIT From: KTOBISKA@gllsvc.jpl.nasa.gov at Internet Date: 2/10/95 11:11AM *To: Karen.L.Buxbaum@ccmail.jpl.nasa.gov at Internet *cc: KTOBISKA@gllsvc.jpl.nasa.gov at Internet Subject: G2 OAP UVS MWG (+AWG,SWG) observation descriptions ------------------------------------------------------------------------------- Sorry, this is the one to use. It has UVS/MWG,AWG,SWG complete. kb _______________________________________________________________________________ Subject: G2 OAP UVS MWG (+AWG,SWG) observation descriptions From: KTOBISKA@gllsvc.jpl.nasa.gov at Internet Date: 2/10/95 11:11 AM UVS AWG: The top priority UVS Jupiter atmospheric observation during this orbit is a recorded far- and mid-ultraviolet (FUV/MUV: 115-320 nm) acetylene-ammonia map (ACELAT). In order to obtain latitudinal resolution better than that which is possible from Earth, the UVS slit is reoriented using a 23 degree science turn. Analysis of the data will result in a unique, seminal data set of stratospheric meridional circulation. Additional atmospheric observations will provide global UV energy budget measurements that are important for energy transfer modeling. Both the darkside/brightside recorded NEWSMP and the realtime BRTMAP observations will provide FUV and MUV full spectral mapping to be used as the baseline for realtime-only observations in other orbits. A recorded ridealong observation with NIMS (GLOMOS) will provide complementary hydrogen (H) Lyman-alpha FUV measurements for brightside global energy mapping and will be compared with infrared measurements. Hydrogen bulge (Lyman-alpha) mapping will continue in this orbit with realtime observations focussing on time variability of specific longitudes (FIXLON) and on longitudinal asymmetries (DRKMAP). Realtime southern auroral full spectral FUV observations will provide longitudinal coverage during one Jupiter rotation. Analysis of the ratios between different spectral lines (color ratios) will yield energies of the electrons precipitating into the auroral zones. 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. There are two general segments of these observations, one set for the G2 inbound torus measurements at the beginning of the G2A encounter period and the second set for the C3 inbound measurements at the end of the G2C cruise period. Both sets of realtime measurements (G2NANS/G2MPRO, C3NANS/C3MPRO/C3NPRO) will map the torus ansae simultaneously with the EUV in S and O 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. Additionally, in conjunction with the MWG's magnetospheric survey, the UVS will conduct magnetonebula measurements (MAGNEB) during the G2B,C outbound cruise period. These long duration realtime measurements of FUV SI and OI emission lines looking down the magnetonebula axis (antisun direction) will integrate the flux in 24-hour segments. UVS SWG: In this orbit, the priority UVS satellite observations will be the recorded bright and dark limb tenuous atmosphere measurements of Ganymede (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 Tammuz Crater (TAMMUZ) and the Ganymede north pole (NRPOLE). Realtime Europa full spectral FUV phase angle observations (EUPHAS), not obtainable from Earth (phases 79, 60, 43, and 58 degrees), will complement NIMS surface property measurements. Realtime Io eclipse full spectral FUV/MUV observations (IECLPS) will characterize airglow emissions as Io enters and exits eclipse. Analysis of these data will provide the morphology of Io's atmosphere 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.