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A Study of the Diurnal Tide in the MLT Region During the 2020 Sudden Stratospheric Warming Over Yinchuan, China (38.8°N, 106.8°E)

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Journal of Geophysical Research: Space Physics
Authors:
Yun Gong at Wuhan University
Yun Gong
Jiaxin Bao at Wuhan University
Jiaxin Bao
Shaodong Zhang
Shaodong Zhang
Shaodong Zhang
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Zheng Ma at Wuhan University
Zheng Ma
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Abstract and Figures

We present a study of diurnal tidal variations in the mesosphere and lower thermosphere (MLT) region over Yinchuan (38.8°N, 106.8°E) during the 2020 Northern Hemisphere winter sudden stratospheric warming (SSW) event. This research utilizes data from a newly established meteor radar at Yinchuan, in conjunction with the Specified Dynamics Whole Atmosphere Community Climate Model with Thermosphere and Ionosphere Extension (SD‐WACCM‐X), the Modern‐Era Retrospective analysis for Research and Applications, Version 2 (MERRA‐2) reanalysis data, and a meteor radar in Beijing, China (40.3°N, 116.2°E). Our analysis reveals a significant enhancement in the amplitude of the diurnal tide during the 2020 SSW in both meridional and zonal wind components, exceeding the climatological mean by two standard deviations. The variation in the ratio of absolute vorticity to planetary vorticity in the MLT region is known to correlate with diurnal tide amplitude. Our findings indicate that the zonal‐mean zonal wind in the MLT underwent a dramatic change during the SSW, with the ratio beginning to decrease 2 days prior to the event. This suggests that changes in the zonal‐mean zonal wind during the SSW may play a crucial role in the observed amplification of the diurnal tidal amplitudes. Nevertheless, further investigations are needed to better understand the amplification of diurnal tides in the MLT region during SSWs.
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A Study of the Diurnal Tide in the MLT Region During the
2020 Sudden Stratospheric Warming Over Yinchuan, China
(38.8°N, 106.8°E)
Yun Gong
1,2
, Jiaxin Bao
1,2
, Shaodong Zhang
1,2,3
, Zheng Ma
1,2
, Qihou Zhou
4
, and
Jiahui Luo
1,2
1
School of Earth and Space Science and Technology, Wuhan University, Wuhan, China,
2
Key Laboratory of Geospace
Environment and Geodesy, Ministry of Education, Wuhan, China,
3
Guizhou Normal University, Guiyang, China,
4
Electrical and Computer Engineering Department, Miami University, Oxford, OH, USA
Abstract We present a study of diurnal tidal variations in the mesosphere and lower thermosphere (MLT)
region over Yinchuan (38.8°N, 106.8°E) during the 2020 Northern Hemisphere winter sudden stratospheric
warming (SSW) event. This research utilizes data from a newly established meteor radar at Yinchuan, in
conjunction with the Specified Dynamics Whole Atmosphere Community Climate Model with Thermosphere
and Ionosphere Extension (SD‐WACCM‐X), the Modern‐Era Retrospective analysis for Research and
Applications, Version 2 (MERRA‐2) reanalysis data, and a meteor radar in Beijing, China (40.3°N, 116.2°E).
Our analysis reveals a significant enhancement in the amplitude of the diurnal tide during the 2020 SSW in both
meridional and zonal wind components, exceeding the climatological mean by two standard deviations. The
variation in the ratio of absolute vorticity to planetary vorticity in the MLT region is known to correlate with
diurnal tide amplitude. Our findings indicate that the zonal‐mean zonal wind in the MLT underwent a dramatic
change during the SSW, with the ratio beginning to decrease 2 days prior to the event. This suggests that changes
in the zonal‐mean zonal wind during the SSW may play a crucial role in the observed amplification of the
diurnal tidal amplitudes. Nevertheless, further investigations are needed to better understand the amplification
of diurnal tides in the MLT region during SSWs.
1. Introduction
A sudden stratospheric warming (SSW) is an intense atmospheric event occurring in the stratosphere over the
polar region during the winter months. It is characterized by a rapid and significant increase in stratospheric
temperature at high latitudes within a short period. SSW events are often accompanied by a weakening or reversal
of the zonal‐mean zonal wind at high latitudes, along with a displacement or splitting of the polar vortex (Andrews
et al., 1987). These events have profound impacts on the structure and dynamics of the entire atmosphere, which
can result in the coupling among the different atmospheric layers. For instance, SSWs can induce significant
changes in wind patterns, temperature distributions, and planetary‐scale oscillations throughout the middle and
upper atmosphere (e.g., Chau et al., 2012; Goncharenko et al., 2013; Gong et al., 2018,2019; Liu & Roble, 2002;
Luo et al., 2023; Ma et al., 2024; Pancheva et al., 2008; Pedatella & Forbes, 2010,2016; Vineeth et al., 2009;
Yamazaki & Matthias, 2019,2021).
Solar tides are atmospheric oscillations driven by solar radiation, primarily caused by the absorption of ultraviolet
radiation in the Earth's atmosphere. This heating process generates temperature and pressure gradients, leading to
periodic variations in atmospheric pressure and temperature, which propagate as tidal waves with periods of 24/
n hrs (where n =1, 2, 3, or 4). These tidal waves propagate through various atmospheric layers and play a crucial
role in affecting the circulation and thermal structure of the mesosphere and lower thermosphere (MLT) region
(Forbes, 1995; Smith, 2012). Chapman and Lindzen (1970) provided a foundational review of atmospheric tide
theory. Since then, numerous observational studies using ground‐based radars (Gong et al., 2013,2021; He
et al., 2020; Krueger et al., 2020; Kumar et al., 2014; Li et al., 2020; She et al., 2016; Yu et al., 2013; Zhang
et al., 2004; Zhou et al., 1997), and satellite observations (Forbes et al., 2021; Oberheide, 2022; Oberheide &
Forbes, 2008; Xu et al., 2010,2014), and numerical studies (Forbes & Zhang, 2022; Hagan et al., 1995,2001;
Huang et al., 2006,2007; Maute et al., 2023; Oberheide et al., 2023; Smith et al., 2004; Vitharana et al., 2019,
2021) have expanded our understanding of atmospheric tidal wave characteristics.
RESEARCH ARTICLE
10.1029/2024JA033427
Key Points:
•An enhancement of a diurnal tide is
observed by a newly built meteor radar
during a sudden stratospheric warming
(SSW) in 2020
•The zonal‐mean zonal wind in the
mesosphere and lower thermosphere
(MLT) region over Yinchuan experi-
enced dramatic changes during
the SSW
•The enhancement of the diurnal tide
during the SSW is strongly associated
with the structure of the zonal‐mean
zonal wind
Correspondence to:
Y. Gong and S. Zhang,
yun.gong@whu.edu.cn;
zsd@whu.edu.cn
Citation:
Gong, Y., Bao, J., Zhang, S., Ma, Z., Zhou,
Q., & Luo, J. (2025). A study of the diurnal
tide in the MLT region during the 2020
sudden stratospheric warming over
Yinchuan, China (38.8°N, 106.8°E).
Journal of Geophysical Research: Space
Physics,130, e2024JA033427. https://doi.
org/10.1029/2024JA033427
Received 10 OCT 2024
Accepted 9 JAN 2025
© 2025. American Geophysical Union. All
Rights Reserved.
GONG ET AL. 1 of 10
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