IAFE   05512
INSTITUTO DE ASTRONOMIA Y FISICA DEL ESPACIO
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
Variability of tides in the mesopause region determined from airglow data at El Leoncito
Autor/es:
J. SCHEER; E.R. REISIN
Lugar:
Bremen,
Reunión:
Congreso; 38th COSPAR Scientific Assembly; 2010
Institución organizadora:
International Council of Science
Resumen:
Tidal signatures obtained from time series of OH(6-2) and O2b(0-1) airglow band intensities and rotational temperatures during many runs of consecutive nights are used to study tidal variability. The data analized were acquired at El Leoncito (31.8ºS 69.3ºW) and correspond to intervals of about 75 days, covering March-April and June-July 2007, and the two December- January seasons in 2007/8 and 2008/9, which includes CAWSES Tidal Campaign intervals. The identi fication of the tide in a given night depends on the behaviour of the four measured parameters which permits to distinguish between nights with clear tidal signatures and those with no tidal activity. Also, in case of a positive identifi cation, reliable quantitative information on tidal amplitude, phase, and vertical propagation is obtained. Of course, this only describes the net eff ect of diff erent migrating and non-migrating tidal modes, at the observation site. We find considerable day-to-day variability with often dramatically diff erent tidal activity in neighbouring nights. This is thought to be due to the combination of variable factors like the sources of excitation, vertical propagation conditions from source altitude to airglow layer, and the (eventually destructive) interference between migrating and non-migrating modes. There are also clear seasonal diff erences in tidal activity, with high amplitudes in autumn and winter, and low activity in summer.