Variations of Mesospheric Neutral Winds and Tides Observed by a Meteor Radar Chain Over China During the 2013 Sudden Stratospheric Warming

Abstract

The neutral winds in the mesospheric and lower thermospheric region obtained from a meteor radar chain within the latitudinal range of 18-53°N were decomposed to examine the latitudinal structures of the tides and mean winds during the sudden stratospheric warming (SSW) event in 2013. The zonal wind reversed from eastward to westward and the westward wind was larger at middle latitudes than that at low latitudes during the SSW. Meanwhile, a sharp increase in the northward wind was noticeable at all stations. The amplitudes of the diurnal and semidiurnal tides decreased from 5 to 13 January and increased subsequently. At the same time, the terdiurnal tides increased in amplitude, especially at Beijing, Wuhan, and Kunming, in response to the SSW. Moreover, the tidal phases showed a large shift that corresponded to a great increase in tidal wavelengths in the semidiurnal and terdiurnal components. The wavelet analysis further revealed that the quasi 6-day wave oscillations dominated in the winds at Kunming and Sanya stations, as well as the quasi 16-day wave dominated in the zonal wind, and the quasi 11-day and 16-day waves were prevailing in the meridional winds at Beijing and Wuhan. In the same vein, the quasi 16-day and quasi 11-day waves were prominent in the zonal and meridional winds during 1-18 January at Mohe. Therefore, the tide-planetary wave interactions played a significant role in modulating the behaviors of the mesospheric and lower thermospheric dynamics during the SSW event.LI ET AL.6 of 16 SSW, the structure of daily variabilities was similar at Beijing, Wuhan, Kunming, and Sanya. However, during the 2013 SSW, the semidiurnal amplitude in the zonal wind decreased over Mohe, Beijing, and Wuhan. It decreased further after~9 days and returned to its normal value at around 17 January over Mohe and Beijing. Whereas the semidiurnal amplitude in the zonal wind decreased before the SSW onset and increased during the SSW onset below 90 km at Kunming and below 94 km at Sanya. The variations of semidiurnal amplitude of the zonal wind before and after the 2013 SSW onset were small at all stations. Overall, there were significant fluctuations in the zonal semidiurnal tides over Wuhan, Kunming, and Sanya.The semidiurnal amplitude of the meridional wind was comparable with that of the zonal wind over Mohe. From Wuhan to Sanya, the semidiurnal amplitude of the meridional wind decreased as the latitude decreased. A similar reduction was observed at all stations during the 2013 SSW. Specifically, the reduction of semidiurnal amplitude

Coupling From the Middle Atmosphere to the Exobase: Dynamical Disturbance Effects on Light Chemical Species

“…Initially, increased eastward GW forcing acts to drive increased eastward zonal mean zonal winds, ultimately inducing a strong change in the modeled meridional residual circulation ( in Figure 6c, see for its derivation Andrews et al, 1987) with enhanced equatorward (and upward, not shown) flow around 100 km, consistent with MR observations (see Li et al, 2020). Through continuity, this residual circulation leads to a net divergence of light species and subsequent high‐latitude decrease in [O], [He], and [H] for the 2012–2013 SSW/MC event, amplifying the expected seasonal decreases (see Figure 3).…”

Comparison of stratospheric evolution during the major sudden stratospheric warming events in 2018 and 2019

“…Sudden stratospheric warming (SSW) is a large‐scale meteorological event that always occurs with the winter polar stratospheric temperature increasing sharply within several days (Matsuno, 1971; Andrews et al, 1987). This polar event is reported to have a large impact on the atmosphere and on the ionosphere at other latitudes (e.g., Ayarzagüena et al, 2011; Gong Y et al, 2013, 2016, 2018a, b; Coy and Pawson, 2015; Butler et al, 2017; Ma Z et al, 2017, 2018, 2020; Xiong JG et al, 2018; Li N et al, 2020). A major SSW event is associated with a reversal of the zonal mean zonal wind (from eastward to westward) at 10 hPa of 60°N and a positive zonal mean temperature difference between 90°N and 60°N at the 10 hPa level.…”

Unexpected Decrease in TW3 Amplitude During Antarctic Sudden Stratospheric Warming Events as Revealed by SD‐WACCM‐X

“…Based on previous studies on TW3, the TW3 amplitudes show a distinct increase in the neutral wind during Arctic SSW events (Fuller‐Rowell et al., 2010, 2011; Jin et al., 2012; Wang et al., 2011). And the terdiurnal tides in the observations also show a distinct increase in the neutral atmosphere during some Arctic SSWs (Fuller‐Rowell et al., 2011; Li et al., 2020; Sathishkumar & Sridharan, 2013; Wu & Nozawa, 2015). In this work, the TW3 amplitudes in the neutral wind from SD‐WACCM‐X are shown during the twelve Arctic SSW events in Figures 10 and 11.…”