Propagation in longitude and altitude of wave 4 thermospheric perturbations from WINDII data at low and high latitudes

Abstract

The diurnal eastward propagating nonmigrating tide of wave number 3 (DE3) has been observed as wave 4 from slowly precessing satellites, for both the ionized and neutral atmospheres. This tide has been identified as arising from deep tropical convection, propagating into the thermosphere and ionosphere, where it has been observed at equatorial latitudes. This feature was previously identified in the Wind Imaging Interferometer (WINDII) O(1S) 557.7 nm emission rate measurements at 250 km in the high‐latitude region as well as the equatorial region. The WINDII wind measurements presented here provide detailed vertical structure from the MLT (Mesosphere and Lower Thermosphere) region to the thermosphere, 100 km to 250 km altitude, the first time that the DE3 winds have been measured over this vertical range. In the present work, the longitudinal propagation of wave 4 at different altitudes is discussed for the daytime and nighttime. The seasonal variations of wave 4 amplitude are compared for different altitudes and latitude regions.