Abstract
The main characteristics (coherences, phase velocities, propagation directions, characteristic periods, and amplitudes) of wave disturbances in the field of pressure and wind speed in the troposphere caused by the solar terminator (ST) moving relative to the Earth are studied. A coherent analysis of pressure variations measured by infrasound microbarographs of the stations IS26 (Germany), IS37 (Norway), and IS43 (Russia) making a triangle with sides of about 2000 km in size is used to detect wave disturbances from the ST. With such a large triangle, it is possible to isolate acoustic-gravity waves of high coherence with ST azimuths and propagation velocities against the background of much slower internal gravity waves (IGWs) from meteorological fronts. Wind speed and atmospheric pressure fluctuations are measured with sodars and microbarographs located in the region of Moscow and forming a small triangle with side lengths from 7 to 60 km. The distributions of the number of signal arrivals over azimuths and horizontal phase speeds are obtained. An explanation is given for the presence of dominant azimuths and phase speeds of internal gravity waves in the small triangle.