HR: 1400h
AN: SA53B-06    [Abstracts]
TI: Semidiurnal tides from the Extended Canadian Middle Atmosphere Model (CMAM) and comparisons with TIMED Doppler Interferometer (TIDI) and meteor radar observations
AU: * Du, J
EM: p531w@unb.ca
AF: Physics Department, University of New Brunswick, P. O.Box 4400, Fredericton, NB, E3B 5A3, Canada
AU: Ward, W E
EM: wward@unb.ca
AF: Physics Department, University of New Brunswick, P. O.Box 4400, Fredericton, NB, E3B 5A3, Canada
AU: Oberheide, J
EM: joberh@uni-wuppertal.de
AF: Physics Department, University of Wuppertal, 42097, Wuppertal, Germany
AU: Nakamura, T
EM: nakamura@rish.kyoto-u.ac.jp
AF: Radio Science Center for Space and Atmosphere, Kyoto University, Uji, Kyoto, 611-0011, Japan
AB: The Extended Canadian Middle Atmosphere Model (extended CMAM) is a general circulation model which extends from the surface to about 210 km. This high upper boundary allows dynamical processes to be studied from the ground to the lower thermosphere without the influence of sponge layers, which are often inserted in the mesosphere. The extended CMAM includes realistic tidal forcing due to radiative heating, convective adjustment and latent heat release and uses the gravity wave breaking parameterization of Hines. In this paper, spatial complex spectral analysis is applied to horizontal winds simulated by the extended CMAM to obtain semidiurnal tidal amplitudes and phases (from e5 to w5) in the mesosphere and lower thermosphere (MLT) region. The dominant w2 migrating component and the presence of nonmigrating tides (w3, e1, e2) in the mid-latitudes are identified. The migrating semidiurnal tide (w2) has amplitudes reaching 20 m/s for both zonal and meridional winds in mid-latitude region. The amplitudes of non-migrating semidiurnal tides are also non- negligible compared to the migrating semidiurnal tides, the amplitudes for w3 exceeds 12 m/s and e2 reaches 8 m/s. Comparisons are made with the TIMED Doppler Interferometer (TIDI) wind measurements, which are analyzed to obtain 6 nonmigrating tidal components (w4, w3, w1, s0, e1, e2) between 85 km and 105 km altitude and between 45oS and 45oN latitude. Overall, the modeled semidiurnal components agree very well with TIDI observations. The 11 semidiurnal components from the model are then superimposed to get the total semidiurnal winds which are compared to two equatorial MWR radar stations (Jakarta and Kototabang). The comparisons between CMAM and two radar stations show that the amplitudes and phases have generally good agreement for semidiurnal tide, with Jakarta station agreeing much better than Kototabang station.
DE: 0550 Model verification and validation
DE: 3389 Tides and planetary waves
DE: 3394 Instruments and techniques
SC: SPA-Aeronomy [SA]
MN: 2007 Joint Assembly