HR: 1340h
AN: P53A-1444    [Abstracts]
TI: New results From HIPWAC Measurements of Ethane in the Stratosphere of Titan
AU: * Sonnabend, G
EM: gsonnabend@lepvax.gsfc.nasa.gov
AF: NAS/NRC/GSFC, NASA GSFC Code 693, Greenbelt, MD 20771 United States
AU: Kostiuk, T
EM: theodor.kostiuk@gsfc.nasa.gov
AF: NASA Goddard Space Flight Center, Code 693, Greenbelt, MD 20771 United States
AU: Livengood, T A
EM: Timothy.A.Livengood@gsfc.nasa.gov
AF: Challenger Center for Space Science Education, 1250 North Pitt Street, Alexandria, VA 22314 United States
AU: Hewagama, T
EM: tilak@cuzco.gsfc.nasa.gov
AF: University of Maryland, NASA GSFC Code 693, Greenbelt, MD 20771 United States
AU: Fast, K E
EM: Kelly.E.Fast@nasa.gov
AF: NASA Goddard Space Flight Center, Code 693, Greenbelt, MD 20771 United States
AU: Annen, J
EM: John.Annen@nasa.gov
AF: NASA Goddard Space Flight Center, Code 693, Greenbelt, MD 20771 United States
AU: Buhl, D
EM: David.Buhl@nasa.gov
AF: NASA Goddard Space Flight Center, Code 693, Greenbelt, MD 20771 United States
AU: Murakawa, K
EM: murakawa@subaru.naoj.org
AF: Subaru Telescope/National Astronomical Observatory of Japan, 650 North A'ohoku Place, Hilo, HI 96720 United States
AU: Tokunaga, A
EM: tokunaga@ifa.hawaii.edu
AF: University oh Hawaii/Hilo, Institute for Astronomy 640 North A`ohoku Place, #209, Hilo, HI 96720 United States
AB: The Goddard Space Flight Center Heterodyne Instrument for Planetary Wind And Composition, HIPWAC, was used at the National Astronomical Observatory of Japan Subaru Telescope on Mauna Kea, Hawaii to measure Ethane emission features near 12 $\mu$m. HIPWAC spectral resolving power of $>$10$^6$ and the 0.36 arcsec diffraction limited FOV on Titan with the 8.2 m Subaru telescope enabled recording of true emission line profiles on the East and West hemispheres of Titan. The direction and magnitude of global stratospheric wind on Titan was determined by analyzing differences in the line frequencies (Doppler shifts). The line profiles were fit to retrieve ethane abundances and constraints on the thermal structure near 0.5 mbar pressures. The near equatorial FOV positions overlapped the Huygens probe entry latitude. Analyses retrieved a prograde wind of 170$\pm$90 m/s. Ethane abundance was 0.7$\pm$0.3 x 10$^{-5}$. The indication of temperature profile variations between the two hemispheres of Titan will be presented and comparisons to 1993-96 InfraRed Heterodyne Spectrometer, IRHS at NASA's InfraRed Telescope Facility will be made. Possible explanations for the temperature differences will be discussed. An outlook for expected results from measurements on Subaru during the descent of Huygens into Titan's atmosphere on January 14, 2005 UT will be given. Work was supported by the NASA Planetary Astronomy Program.
DE: 6280 Saturnian satellites
DE: 3360 Remote sensing
DE: 3319 General circulation
DE: 0300 ATMOSPHERIC COMPOSITION AND STRUCTURE
SC: Planetary Sciences [P]
MN: 2004 AGU Fall Meeting