HR: 0800h
AN: SA41A-1046    [Abstracts]
TI: First Simultaneous MLT and Thermospheric F-region Observations
AU: * Balan, N
EM: B.Nanan@sheffield.ac.uk
AF: University of Sheffield, Control and Systems Engineering, Mappin Street, Sheffield, S1 œJD United Kingdom
AU: Kawamura, S
EM: s-kawamura@nict.go.jp
AF: NICT, 4-2-1 Nakui Kilamachi, Koganei-shi, Tokyo, 184-8795 Japan
AU: Nakamura, T
EM: nakamura@rasc.kyoto-u.ac.jp
AF: Kyoto University, RASC, Uji, Kyoto, 611 Japan
AU: Yamamoto, M
EM: yamamoto@rasc.kyoto-u.ac.jp
AF: Kyoto University, RASC, Uji, Kyoto, 611 Japan
AU: Fukao, S
EM: fukao@rasc.kyoto-u.ac.jp
AF: Kyoto University, RASC, Uji, Kyoto, 611 Japan
AU: Alleyne, H
EM: h.alleyne@sheffield.ac.uk
AF: University of Sheffield, Control and Systems Engineering, Mappin Street, Sheffield, S1 œJD United Kingdom
AB: Earth's thermosphere and the embedded ionosphere, called the thermospheric F region, have been studied in numerous publications. From these studies, it is known that complete understanding of the behavior of the thermospheric F region requires its coupling to the magnetosphere above and the mesosphere lower-thermosphere (MLT) region below. Recently, we have started observing the MLT and thermospheric F regions simultaneously by operating the MU radar (35$^{\circ}$N, 136$^{\circ}$E) in alternate meteor and incoherent scatter (IS) modes under a project called MTEC-S (Mesosphere Thermosphere Experiments for Coupling Studies), with a view to identify the tides and waves that can dynamically couple the upper atmospheric regions. The MTEC-S observations (each lasting more than a week) provide simultaneous zonal and meridional wind velocities at MLT altitudes (80-95 km), meridional wind velocity in the upper thermosphere (220-450 km), and electron density (150-600 km), peak height and plasma drift velocity in the ionosphere with a time resolution of 1.5 hours. The long data sets, one in each season during 2000-01, and their spectra are used to obtain the mean winds, and tides and waves that can couple the MLT and thermospheric F regions in different seasons. The seasonal and solar activity dependencies of the mean wind velocity and tidal amplitudes (of periods 24 and 12 hours) at the MLT and thermospheric F region altitudes are also presented.
DE: 2427 Ionosphere/atmosphere interactions (0335)
DE: 2437 Ionospheric dynamics
DE: 2443 Midlatitude ionosphere
DE: 0355 Thermosphere--composition and chemistry
SC: SPA-Aeronomy [SA]
MN: 2004 AGU Fall Meeting