HR: 0830h
AN: SA51A-0500    [PDF]
TI: Mesosphere Thermosphere Experiments for Coupling Studies
AU: * Balan, N
EM: B.Nanan@sheffield.ac.uk
AF: Control and Systems Engineering, University of Sheffield, Sheffield, S1 3JD United Kingdom
AU: Kawamura, S
AF: Radio Science Center for Space and Atmosphere, Kyoto University, Kyoto, 611-0011 Japan
AU: Nakamura, T
AF: Radio Science Center for Space and Atmosphere, Kyoto University, Kyoto, 611-0011 Japan
AU: Yamamoto, M
AF: Radio Science Center for Space and Atmosphere, Kyoto University, Kyoto, 611-0011 Japan
AU: Fukao, S
AF: Radio Science Center for Space and Atmosphere, Kyoto University, Kyoto, 611-0011 Japan
AU: Alleyne, H
AF: Control and Systems Engineering, University of Sheffield, Sheffield, S1 3JD United Kingdom
AB: The mesosphere lower-thermosphere (MLT) and thermospheric F regions at low-mid latitudes are studied simultaneously by operating the MU radar (35$^{\circ}$N, 136$^{\circ}$E) continuously in alternate meteor and incoherent scatter modes, for the first time, under a project called MTEC-S (mesosphere thermosphere experiments for coupling studies). Four long MTEC-S campaigns of duration 7 to 10 days were conducted, one in each season in 2000-01, when solar activity ranged from medium to very high (F10.7 = 130 to 270), and a major morning storm (Dst reaching -360 nT, Kp reaching 9 and Ap rising above 120) and another moderate nighttime storm occurred during a campaign at March equinox. The campaigns provide zonal and meridional wind velocities at MLT altitudes (80-95 km), meridional wind velocity in the upper thermosphere (220-450 km), and electron density, peak height and plasma drift velocity in the ionosphere (150-600 km) with time resolution of 1.5 hours. The observed directions of the meridional wind velocity in the lower and upper thermospheres under quiet and active conditions seem to be consistent with those expected from solar driven thermospheric meridional circulation and auroral driven equatorward wind [{\it Roble et al.,} 1977; {\it Richmond}, 1978; {\it Rishbeth}, 1998]. The response of the ionosphere to the major morning storm is found to be dominated by the direct effect of the storm-time neutral wind during daytime and its indirect effect at night. The data sets are spectral analysed to identify the tides and waves present at different altitudes. The seasonal, solar activity and magnetic activity dependencies of these tides and waves, through which the upper atmospheric regions could be dynamically coupled, are also presented.
DE: 2427 Ionosphere/atmosphere interactions (0335)
DE: 2435 Ionospheric disturbances
DE: 2443 Midlatitude ionosphere
DE: 3332 Mesospheric dynamics
DE: 3369 Thermospheric dynamics (0358)
SC: SPA - Aeronomy [SA]
MN: 2003 Fall Meeting