Comparison of ICON/MIGHTI and TIMED/TIDI Neutral Wind Measurements in the Lower Thermosphere

Abstract

The Earth's upper atmosphere is a dynamic environment and neutral winds are a critical component of it. Neutral winds control a large part of the dynamics within the coupled upper atmosphere and ionosphere system and thus plays an important role in determining the state of the ionosphere-thermosphere (I-T) system at all latitudes. Due to the geometry of the Earth's geomagnetic field, neutral winds at lower latitudes can generate electric fields via the dynamo effect and push the ionospheric plasma upward and downward along the magnetic field lines (e.g.,

Validation of MIGHTI/ICON Atmospheric Wind Observations over China Region Based on Meteor Radar and Horizontal Wind Model (HWM14)

“…Harding et al showed a strong correlation (r = 0.82) between ICON-MIGHTI and specular meteor radars for coincident wind measurements with an average error of 4.5 m/s [19]. The agreement of MIGHTI/ICON and TIMED/TIDI atmospheric wind measurements in the MLT region has also been shown in Dhadly et al [14]. However, no study has yet considered the consistency of meteor radar and MIGHTI/ICON measurements of neutral wind in the MLT region on the basis of a full year of detection data.…”

“…Comparing the results shown above, it could be seen that the consistency of zonal wind measurements from MIGHTI/ICON and meteor radar is better than that of meridional wind measurements, which may be caused by the orbit configuration of the ICON satellite [14]. The measurement of meridional wind from MIGHTI/ICON is naturally less accurate than that of zonal wind due to the north-south motion of the ICON satellite around Wuhan.…”

“…For example, the High-Resolution Doppler Imager (HRDI) and the Wind Imaging Interferometer (WINDII) onboard the UARS satellite first measure atmospheric winds within the height ranges of 50-115 km and 90-180 km by observing the Doppler shift characteristics of O2 airglow emission and O airglow emission, respectively [13]. The High-Resolution Doppler Imager on the Thermosphere Ionosphere Mesosphere Energetics and Dynamics Doppler Interferometer (TIDI), launched in 2001, has been monitoring MLT winds for two decades and has collected the most comprehensive global information on neutral winds [14]. The wind observations have been cross-validated by using ground-based instruments and there is no statistically significant difference for horizontal winds [13,14], which indicates that space-borne instruments can also provide an accurate wind measurement.…”

“…The High-Resolution Doppler Imager on the Thermosphere Ionosphere Mesosphere Energetics and Dynamics Doppler Interferometer (TIDI), launched in 2001, has been monitoring MLT winds for two decades and has collected the most comprehensive global information on neutral winds [14]. The wind observations have been cross-validated by using ground-based instruments and there is no statistically significant difference for horizontal winds [13,14], which indicates that space-borne instruments can also provide an accurate wind measurement.…”

“…The Michelson Interferometer for Global High-resolution Thermospheric Imaging (MIGHTI) onboard the ICON can view airglow emissions from OI 557.7 and 630.0 nm to determine Doppler wind [15][16][17]. A series of cross-comparisons of ICON wind observations with ground-based and space-borne instruments have been carried out by recent research [14,18,19]. Makela et al presented MIGHTI/ICON and ground-based Fabry-Perot interferometer measurements of the nocturnal thermospheric neutral wind and showed consistency within 10 m/s [18].…”