The Morphology of the 6‐Day Wave in Both the Neutral Atmosphere and F Region Ionosphere Under Solar Minimum Conditions

Abstract

AbstractCombined Thermosphere‐Ionosphere‐Mesosphere Energetics and Dynamics (TIMED)/TIMED Doppler interferometer horizontal winds, Global Positioning System Total Electron Content maps, and Constellation Observing System for Meteorology, Ionosphere, and Climate electron density profiles are utilized to study the westward zonal wavenumber 1 quasi‐6‐day planetary wave in both the neutral atmosphere and F region ionosphere under solar minimum conditions in 2009. It is found that the zonal (meridional) wind perturbations maximize (minimize) in the geographic equatorial mesosphere and lower thermosphere region and are in phase (out of phase) between hemispheres, which agrees well with both the Upper Atmosphere Research Satellite/high‐resolution Doppler imager wind observations and (1, 1) Rossby normal mode. Analysis of the Total Electron Content maps and Constellation Observing System for Meteorology, Ionosphere, and Climate electron density profiles shows that the F region ionosphere exhibits wave spectra and temporal variations that are consistent with those of the neutral atmosphere. Specifically, the 6‐day oscillation in electron density is the highest during 1200–1800 LT in the equatorial ionospheric anomaly region (~20° geomagnetic latitude), with a minimum amplitude at the equator, which agrees well with the F region fountain effect. At 300 km, the amplitude of the electron density oscillation reaches ~1.2 × 104 cm−3, which accounts for ~14% of the background value. In addition, the F2 layer electron peak density and peak height also exhibit corresponding oscillations with amplitudes of ~9 × 104 cm−3 and ~12 km, respectively. The current work provides clear evidence for F region ionospheric responses to planetary waves in the mesosphere and lower thermosphere region.