A quasi‐27‐day wave (Q27DW) caused by the rotational period of solar radiation is commonly observed in the atmospheric dynamics. In the present study, we report an enhancement of a Q27DW during recurrent geomagnetic storms in the autumn of 2018 based on the zonal wind observations in the mesosphere and lower thermosphere (MLT) region over Beijing (BJ, 40.3°N, 116.2°E). According to our analysis, the solar radiation and the seasonal variation are not important in exciting the observed Q27DW. A 27‐day oscillation exists in both solar wind data and
Neutral temperature responses in the mesosphere and lower thermosphere (MLT) to severe geomagnetic storms induced by coronal mass ejections (CMEs) are of growing interest to the space science research community. Recently, it was found that geomagnetic activities produced by the corotating interaction regions (CIRs) caused comparable effects on the Earth's upper atmosphere. In this work, we carried out a comparative study of the temperature responses in the MLT region to these two types of geomagnetic activities, using the temperature measured by the Sounding of the Atmosphere using Broadband Emission Radiometry (SABER) instruments onboard the Thermosphere, Ionosphere, Mesosphere Energetics and Dynamics (TIMED) satellite. Our results demonstrate that CIR‐induced geomagnetic activity produced temperature variations in the MLT region and that this effect can penetrate downward to ∼100 km at high latitudes in both hemispheres. Temperature enhancements penetrated deeper during CME‐induced geomagnetic activities, but the heating effects lasted longer during CIR‐induced geomagnetic activities. There is a hemispherical asymmetry in the geomagnetical activity induced temperature changes in the MLT region. The temperature enhancements are stronger in the southern hemisphere than in the northern hemisphere during CME events.
more » « less- NSF-PAR ID:
- 10374434
- Publisher / Repository:
- DOI PREFIX: 10.1029
- Date Published:
- Journal Name:
- Journal of Geophysical Research: Space Physics
- Volume:
- 126
- Issue:
- 6
- ISSN:
- 2169-9380
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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