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https://doi.org/10.5194/egusphere-2026-1883
© Author(s) 2026. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
https://doi.org/10.5194/egusphere-2026-1883
© Author(s) 2026. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
10 Apr 2026
| 10 Apr 2026
Status: this preprint is open for discussion and under review for Atmospheric Chemistry and Physics (ACP).
First Observations of the Solar-Heating Imprint on Seasonal Variations in Diurnal Tidal Structure in the MLT Region
Abstract. A global climatology of diurnal tides in the mesosphere and lower thermosphere (MLT) is constructed using multiyear observations from fifteen meteor radars distributed worldwide. The results show that diurnal tidal amplitudes are strongest at low and mid-latitudes (10°–50° N/S), with peak values of about 60 m s-1 near 20°–30° N/S, and are comparatively weak near the Equator and at polar latitudes. The seasonal variations of the diurnal tide are characterized by maxima around the equinoxes and minima during the solstices. In addition to these global climatological features, we identify a clear modulation of the vertical structure of diurnal tidal amplitude and phase by seasonal variations in solar forcing, represented here by the solar zenith angle (SZA). This modulation is particularly evident at northern low and mid-latitudes, but is much weaker in the Southern Hemisphere. The hemispheric asymmetry suggests that the tidal response to solar forcing is not globally uniform. To further explore the possible cause of this asymmetry, we examine the meridional fluxes of zonal tidal momentum. The results suggest that background zonal winds can influence tidal propagation through filtering effects and momentum drag, thereby contributing to the observed hemispheric differences in tidal structure. These results provide new observational evidence for the coupling between solar forcing and diurnal tides in the MLT region and offer useful constraints for the evaluation of general circulation models. They also improve our understanding of tidal propagation and variability in the middle and upper atmosphere.
How to cite. Yi, W., Wang, J., Xue, X., Yang, C., Reid, I. M., Vincent, R. A., Mackinnon, A., Murphy, D. J., Gulbrandsen, N., Tsutsumi, M., Ning, B., Li, G., Mitchell, N. J., Moffat-Griffin, T., Tsuda, T., Liu, A. Z., Qiao, Z., Li, H., Batista, P. P., Wu, J., Chen, T., and Dou, X.: First Observations of the Solar-Heating Imprint on Seasonal Variations in Diurnal Tidal Structure in the MLT Region, EGUsphere [preprint], https://doi.org/10.5194/egusphere-2026-1883, 2026.
Publisher's note: Copernicus Publications remains neutral with regard to jurisdictional claims made in the text, published maps, institutional affiliations, or any other geographical representation in this paper. While Copernicus Publications makes every effort to include appropriate place names, the final responsibility lies with the authors. Views expressed in the text are those of the authors and do not necessarily reflect the views of the publisher.
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CAS Key Laboratory of Geospace Environment, School of Earth and Space Sciences, University of Science and Technology of China, Hefei, China
State Key Laboratory of Environment Characteristics and Effects for Near-space, Beijing, China
CAS Center for Excellence in Comparative Planetology, Anhui Mengcheng Geophysics National Observation and Research Station, University of Science and Technology of China, Hefei, China
Jianyuan Wang
School of Microelectronics, Tianjin University, Tianjin, China
CAS Key Laboratory of Geospace Environment, School of Earth and Space Sciences, University of Science and Technology of China, Hefei, China
State Key Laboratory of Environment Characteristics and Effects for Near-space, Beijing, China
CAS Center for Excellence in Comparative Planetology, Anhui Mengcheng Geophysics National Observation and Research Station, University of Science and Technology of China, Hefei, China
Hefei National Laboratory, University of Science and Technology of China, Hefei, China
Chengyun Yang
CAS Key Laboratory of Geospace Environment, School of Earth and Space Sciences, University of Science and Technology of China, Hefei, China
CAS Center for Excellence in Comparative Planetology, Anhui Mengcheng Geophysics National Observation and Research Station, University of Science and Technology of China, Hefei, China
Iain M. Reid
ATRAD Pty Ltd., Underdale, South Australia, Australia
School of Physical Sciences, University of Adelaide, Adelaide, South Australia, Australia
Robert A. Vincent
ATRAD Pty Ltd., Underdale, South Australia, Australia
School of Physical Sciences, University of Adelaide, Adelaide, South Australia, Australia
Andrew Mackinnon
School of Physical Sciences, University of Adelaide, Adelaide, South Australia, Australia
Damian J. Murphy
Australian Antarctic Division, Kingston, Tasmania, Australia
Njål Gulbrandsen
Tromsø Geophysical Observatory, UiT – The Arctic University of Norway, Tromsø, Norway
Masaki Tsutsumi
National Institute of Polar Research, Tachikawa, Japan
Baiqi Ning
Key Laboratory of Earth and Planetary Physics, Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing, China
Guozhu Li
Key Laboratory of Earth and Planetary Physics, Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing, China
Nicholas J. Mitchell
British Antarctic Survey, Cambridge, UK
Department of Electronic & Electrical Engineering, The University of Bath, UK
Tracy Moffat-Griffin
Department of Electronic & Electrical Engineering, The University of Bath, UK
Toshitaka Tsuda
Research Institute for Sustainable Humanosphere (RISH), Kyoto University, Uji, Japan
Alan Z. Liu
Center for Space and Atmospheric Research, Department of Physical Sciences, Embry-Riddle Aeronautical University, Daytona Beach, Florida, USA
Zishun Qiao
High Altitude Observatory, NSF National Center for Atmospheric Research, Boulder, Colorado, USA
Haiying Li
National Key Laboratory of Electromagnetic Wave Propagation, China Research Institute of Radiowave Propagation, Qingdao, China
Paulo P. Batista
Heliophysics, Planetary Science and Aeronomy Division, National Institute for Space Research-INPE, São José dos Campos, SP, Brazil
Jianfei Wu
CAS Key Laboratory of Geospace Environment, School of Earth and Space Sciences, University of Science and Technology of China, Hefei, China
CAS Center for Excellence in Comparative Planetology, Anhui Mengcheng Geophysics National Observation and Research Station, University of Science and Technology of China, Hefei, China
Tingdi Chen
CAS Key Laboratory of Geospace Environment, School of Earth and Space Sciences, University of Science and Technology of China, Hefei, China
CAS Center for Excellence in Comparative Planetology, Anhui Mengcheng Geophysics National Observation and Research Station, University of Science and Technology of China, Hefei, China
Xiankang Dou
CAS Key Laboratory of Geospace Environment, School of Earth and Space Sciences, University of Science and Technology of China, Hefei, China
Hefei National Laboratory, University of Science and Technology of China, Hefei, China
Short summary
This study provides observational evidence that the solar zenith angle (SZA) influences the vertical structure of diurnal tides in the MLT region. Diurnal tides are strongest at low and mid-latitudes (10–50° N/S) and weaker near the Equator and at polar latitudes. The results further suggest that background zonal winds influence tidal propagation and structure through filtering and momentum drag.
This study provides observational evidence that the solar zenith angle (SZA) influences the...