Variabilidade na amplitude da maré lunar no conteúdo eletrônico total sobre o Brasil

Abstract

Using Total Electron Content (TEC) data for four years of data from 2011 to 2014 it was possible to investigate the dynamics of the upper atmosphere more specifically the ionosphere. TEC data were provided by the space climate program, EMBRACE (Brazilian Space Climate Study and Monitoring) from INPE (National Institute for Space Research) and have a 10-minute temporal resolution, allowing studying the Lunar Atmospheric Tide with good accuracy. This work uses TEC measurements to investigate the variability of the Lunar Tide amplitude in the four years of data in the fixed magnetic latitudes of 10 °, 0 °, -10 ° and -20°. The aim of this research was to observe the Tidal modulation by waves of planetary scale and to verify the effect of the abrupt warming events of the polar stratosphere (Sudden Stratospheric Warming SSW). As a result, it was observed that the variability in Tide amplitude is seen in the four years of data for both the diurnal component and the semidiurnal component. The highest amplitude values are seen for the diurnal tide in all studied latitudes. The lowest amplitude values were concentrated for the magnetic equator. The short period oscillations observed in Tide amplitude were concentrated between 8, 9, 10, 11 e 13 days. Among the long period oscillations, the modulations seen in 180, 260 and 360 days highlight, where these oscillations may be related to waves of a planetary scale. In the semidiurnal Tide, it is possible to observe an annual oscillation behavior in all latitudes, while for the diurnal one, there is a semiannual oscillation behavior in the latitudes of 0 °, -10 ° and -20 °. The effect of the SSW event was more effective in the semidiurnal Tide in January 2013, promoting an increase in the Tide amplitude in all studied latitudes.