Produção Nacional
Revisado por pares
Variability of the quasi-2-day wave and interaction with longer period planetary waves in the MLT at Cachoeira Paulista (22.7°S, 45°W)
2015; Elsevier BV; Volume: 130-131; Linguagem: Inglês
10.1016/j.jastp.2015.05.010
ISSN1879-1824
AutoresA. Guharay, P. P. Batista, B. R. Clemesha,
Tópico(s)Atmospheric Ozone and Climate
ResumoAn exclusive study has been carried out with long term meteor wind data (2000–2014) to characterize the quasi-2-day wave (QTDW) in the mesosphere and lower thermosphere (MLT) and its interactions with the longer period planetary waves at Cachoeira Paulista (22.7°S, 45°W). The QTDW is observed to be dominant during late summer (January–February) all the years under consideration except 2013. All the wave parameters exhibit significant interannual variability. The maximum wave amplitude comes out to be 39 m/s, which is significantly higher than the reported northern hemispheric findings. The mean MLT period exhibits a wide range of variability (36–70 h) indicating the presence of multiple Rossby normal modes with varying zonal wave numbers. Modulations of the QTDW amplitude by the planetary waves with longer periodicities (>9 days) are evident, especially during summer. The nonlinear interactions between the 2-day wave and longer period waves are believed to give rise to a host of secondary waves with frequencies lying close to 2-day. The strong QTDW activity, as observed at this location, has potential to cause significant effect on the overlying ionosphere and hence the atmosphere-ionosphere dynamical coupling.
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