Atmosphere-Ionosphere coupling observed over the dip equatorial MLTI region through the quasi 16-day wave

The present paper analyses the variations of daytime mesopause temperature and the Equatorial electrojet strength over the dip equator during December 2005-March 2006 period, indicating a possible strong dynamical coupling between the two region through the intensification of planetary wave activity. The wave signatures (quasi 16-day period) are seen in the mesopause temperature and the electrojet-induced surface magnetic field, measured from Trivandrum (8.5° N, 76.5° E, 0.5° N diplat.), a geomagnetic dip equatorial station in India. This investigation reveals (1) amplification of the quasi 16-day wave in the equatorial mesopause temperature and the EEJ induced magnetic field (2) regular occurrence of Counter Electrojet (CEJ), with a periodicity of -16 days (3) diminishing CEJ strength concurrent with the damping of the amplitude of wave oscillation with time. These results are new and reveal some newer aspects of the Mesosphere Lower Thermosphere Ionosphere (MLTI) dynamics