Day‐To‐Day Variability of the MLT DE3 Using Joint Analysis on Observations From TIDI‐TIMED and a Meteor Radar Meridian Chain

Abstract

In the present work, daily variation of eastward propagating diurnal tide with zonal‐wave number 3 (DE3) is derived from joint analysis on observations from Thermosphere Ionosphere Mesosphere Energetics and Dynamics Doppler Interferometer and a meteor radar chain around meridian 120°E during years of 2012–2015 and 2018–2020 via a novel method. Together with empirical tidal modes (ETMs), which are based on the Global Scale Wave Model, daily DE3 in horizontal winds are extracted. ETMs characterize the two‐dimensionally latitude‐altitudinal tidal structure with consideration of tidal dissipation, and thus makes it possible to obtain the DE3 tide extending to pole‐to‐pole in latitudes and covering 80–140 km on altitudes. Quantitatively analyzing day‐to‐day variability of mesosphere and lower thermosphere DE3 reveals that the variation of tidal phase is the main contributor to the DE3 day‐to‐day variability for both zonal and meridional winds. The strength of tidal‐phase induced variability has a clear seasonal dependence that is strong around June and December solstices. Prominent semiannual oscillation (SAO) for zonal (∼16%) and meridional (∼24%) winds are revealed, and annual oscillation (AO) is superposed on the SAO for the DE3 in meridional winds (∼9%). Tidal‐phase induced variability is generally stronger in solar minima (2018–2020) than that in solar maxima (2013–2015). Furthermore, a comparison with simulations using the Whole Atmosphere Community Climate Model eXtended is discussed. The simulations confirm that the primary role of tidal‐phase variations on the day‐to‐day variability. The model does not reproduce the SAO as shown in observations, while the AO in meridional winds is simulated well.

The Spatiotemporal Variability of Non‐Migrating Tides in the Zonal Wind Component Detected From TIMED/TIDI Observations

“…This intra‐annual variation in the DE3 short‐term variability is in accordance with the simulation results of Liu (2014) and the meteor radar observations of Zhou et al. (2022). Liu (2016) inferred that the dominant dynamic processes of the DE3 in zonal wind were planetary waves, and their day‐to‐day variability was shown to be stochastic by calculating the correlation time.…”

“…The different latitudinal variabilities of the DE3 in the zonal wind component indicate that the DE3 tide at different latitudes was dominated by wave modes with different symmetries: the symmetric DE3 tidal mode at lower latitudes and the asymmetric DE3 tidal mode at 15°–30° latitudes. This phenomenon is consistent with previous studies (i.e., Li et al., 2019; Oberheide & Forbes, 2008; Zhou et al., 2022). In addition, the symmetric and asymmetric DE3 tidal amplitudes both had peaks in August and September, as shown in the first two column plots in Figure 9.…”

“…About this phenomenon we plan to research the detailed physical mechanism in future. Oberheide and Forbes (2008) and Zhou et al (2022) noted that the symmetric mode of the DE3 day-to-day variation in zonal wind is dominated by Hough Mode Extension (HME) and a set of empirical tidal modes (ETMs). In this work, the symmetric and asymmetric components of the DE3 tide in the zonal wind component were analyzed and presented in Figure 9.…”

Multistatic meteor radar observations of two-dimensional horizontal MLT wind

“…Wuhan (e.g, Zhou et al, 2022) meteor radars, which all operate at 38.9 MHz. The new multistatic meteor radar system will achieve three backscatter (monostatic) links and five forward scatter (bistatic) links, which would provide us with 6 times more meteor detections than a conventional (monostatic) meteor radar.…”

Symmetric and Antisymmetric Solar Migrating Semidiurnal Tides in the Mesosphere and Lower Thermosphere

“…Amplitude and phase of tides change on various time scales, including day-to-day (e.g., Nguyen & Palo, 2013;Dhadly et al, 2018;J. C. Wang et al, 2021;Zhou et al, 2018Zhou et al, , 2022, subseasonal (e.g., Gasperini et al, 2020;Kumari et al, 2020), seasonal (e.g., X. Zhang et al, 2006;Yuan et al, 2008;Mukhtarov et al, 2009;Oberheide et al, 2011), andinterannual (e.g., Burrage et al, 1995;Gan et al, 2014;Gurubaran et al, 2005;Sun et al, 2018;Vincent et al, 1998) variations.…”