Estrutura dos ventos médios e das marés atmosféricas na região meteórica sobre o cariri paraibano.

Abstract

The equatorial region of the upper mesosphere and low thermosphere (MLT), which extended from 80 up to 110 km of the altitude, is of great importance to the atmospheric science because a lot of physical and chemistry phenomena occur in that region. Related to this work, we can mention the natural oscillations, such as, gravity, planetary and tide waves which are responsible for the general circulation of wind at those altitudes. The winds in the region of the MLT over Cariri have being observed since June 2004 when a meteor radar was installed in that region. The goal of this work was to study zonal and meridional winds and tides waves (amplitudes and phase of diurnal, semidiurnal and terdiurnal tides) in order to describe the behavior of those physical parameters for about two years of data, more specifically from August 2004 to August 2006. The data of the observed winds had been compared with HWM93 and CIRA models, whereas, the amplitudes and phases of the observed tides, had been compared with the GSWM00 model. The meridional mean winds had presented annual behavior with southward tendency, whereas, the zonal winds had presented semiannual behavior, westward tendency. Both components presented a good agreement with HWM93 model. However tho CIRA model which showed weak agreement with observed data. In despite of diurnal tide amplitude, both components presented a clear semiannual behavior and a good agreement with GSWM00 model was observed. On the other hand, the amplitude of semidiurnal tide showed different behaviors depending on the component, for example: the meridional presented semiannual oscillation more pronounced about 99 km and annual trend with minimum in January, but, the zonal component presented an annual trend with maximum values in November. The phase of diurnal and semidiurnal tides of both components, presented a seasonal behavior also. Because the amplitude of terdiurnal tides of both components were very small, it was impossible to observe a regular behavior of terdiurnal phases.