EGU21-7320
https://doi.org/10.5194/egusphere-egu21-7320
EGU General Assembly 2021
© Author(s) 2021. This work is distributed under
the Creative Commons Attribution 4.0 License.

The hemispheric asymmetry of ionospheric lunitidal signatures during Sudden Stratospheric Warmings in the eastern Asian and American sectors

Jing Liu1, Donghe Zhang1, Larisa Goncharenko2, Shun-Rong Zhang2, Maosheng He3, Yongqiang Hao1, and Zuo Xiao1
Jing Liu et al.
  • 1Department of Geophysics, Peking University, Beijing, China
  • 2MIT Haystack Observatory, Westford, Massachusetts, USA
  • 3Leibniz-Institute for Atmospheric Physics at Rostock University, Germany

During Sudden Stratospheric Warming events, the ionosphere exhibits phase-shifted semi-diurnal perturbations, which are typically attributed to vertical coupling associated with the semi-diurnal lunar tide (M2). Our understanding of ionospheric responses to M2 is limited. This study focuses on fundamental vertical coupling processes associated with the latitudinal extent and hemispheric asymmetry of ionospheric M2 signatures, using total electron content data from the eastern Asian and American sectors. Our results illustrate that the asymmetry maximizes at around 15°N and 20°S magnetic latitudes. In the southern hemisphere, the M2-like signatures extend deep into midlatitude and, in the American sector, encounter the Weddell Sea Anomaly. The M2 amplitude is larger in the northern hemisphere and such asymmetry is more distinct in the eastern Asian sector. The hemispheric asymmetry of M2 signatures in the low latitude can be primarily explained by the trans-equatorial wind modulation of the equatorial plasma fountain. Other physical processes could also be relevant, including hemispheric asymmetry of the M2 below the F region, the ambient thermospheric composition and ionospheric plasma distribution, and the geomagnetic field configuration.

How to cite: Liu, J., Zhang, D., Goncharenko, L., Zhang, S.-R., He, M., Hao, Y., and Xiao, Z.: The hemispheric asymmetry of ionospheric lunitidal signatures during Sudden Stratospheric Warmings in the eastern Asian and American sectors, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-7320, https://doi.org/10.5194/egusphere-egu21-7320, 2021.

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