Investigation of solar cycle dependence of the tides in the low latitude MLT using meteor radar observations. (15th October 2019)

• Record Type: Journal Article
• Authors: Guharay, A.; Batista, P.P.; Andrioli, V.F.
• Is Part Of: Journal of atmospheric and solar-terrestrial physics. Volume 193(2019)
• Publication Date: 2019-10-15
• Subjects: Tides -- Meteor radar observations -- Middle atmosphere dynamics; Geophysics -- Periodicals; Atmospheric physics -- Periodicals; Géophysique -- Périodiques; Météorologie physique -- Périodiques; Electronic journals; 551.51
• DOI: 10.1016/j.jastp.2019.105083
• Languages: English
• ISSNs: 1364-6826

Abstract

Abstract: Solar cycle dependence of the dominant tides, i.e. diurnal and semidiurnal components in the mesosphere and lower thermosphere (MLT) is investigated from a Southern hemispheric low-latitude station, Cachoeira Paulista (22.7 o S, 45 o W) using long-term meteor wind observations (1999–2018). Although the long-term variations of the tides in aggregate do not show any significant relationship with the solar activity, the individual seasonal profiles reveal appreciable correlation in equinoxes with maximum in fall and no evident correlation in summer. The diurnal tide seasonal profiles show negative correlation with the solar activity and the semidiurnal tide exhibits both negative and positive correlations that vary with altitude within the MLT. The zonal diurnal tide shows positive correlation with the solar flux in the upper MLT in solar minima. However, the meridional semidiurnal tide reveals negative correlation in solar minima condition. No evident relationship between the tides and solar flux is found in solar maxima condition. Since the present study points out resemblance as well as dissimilarity with a handful of previous investigations, further long-term and coordinated studies are being sought to obtain critical understanding of the persistent enigmatic features. Highlights: Evident relationship between the tides and solar radiation is found at low-latitude. Correlation between the tide and solar flux reveals significant seasonal variation. Notable relationship of tides with solar flux is observed in solar minima.