Ionospheric Disturbances in Low‐ and Midlatitudes During the Geomagnetic Storm on 26 August 2018
Name
JGR Space Physics - 2022 - Chang - Ionospheric Disturbances in Low‐ and Midlatitudes During the Geomagnetic Storm on 26.pdf
Description
Published version
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4.36 MB
Format
Adobe PDF
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Author(s)
Chang, Hyeyeon
Kil, Hyosub
Sun, Andrew K
Zhang, Shun‐Rong
Lee, Jiyun
Date Issued
January 24, 2022
Journal
Journal of Geophysical Research: Space Physics
Publisher
American Geophysical Union
Citation
Chang, H., Kil, H., Sun, A. K., Zhang, S.-R., & Lee, J. (2022). Ionospheric disturbances in low- and midlatitudes during the geomagnetic storm on 26 August 2018. Journal of Geophysical Research: Space Physics, 127, e2021JA029879.
Version
Final published version
Abstract
Plasma density depletions at midlatitudes during geomagnetic storms are often understood in terms of equatorial plasma bubbles (EPBs) due to their morphological similarity. However, our study reports the observations that reveal the generation of plasma depletions at midlatitudes by local sources. During the geomagnetic storm on 26 August 2018, the Defense Meteorological Satellite Program and Swarm satellites detected plasma depletions at midlatitudes in the Asian sector in the absence of EPBs in the equatorial region. This observation and the total electron content (TEC) maps over Japan demonstrate that traveling ionospheric disturbances (TIDs) are the sources of midlatitude plasma depletions in the Asian sector. Near the west coast of the United States, the development of a narrow TEC depletion band was identified from TEC maps. The TEC depletion band, which is elongated in the northwest–southeast direction, moves toward the west with a velocity of approximately 240 m/s. The TEC at the TEC depletion band is about 5 TEC units (1016 m−2) smaller than the ambient TEC. As this band is confined to the midlatitudes, this phenomenon is not associated with an EPB. The characteristics of the TEC depletion band are consistent with those of medium-scale TIDs. Observations in the Asian sector and the TEC depletion band over the United States demonstrate that plasma depletions can develop at midlatitudes by local sources. Therefore, the morphological similarity between midlatitude irregularities and EPBs or their coincident occurrence does not provide corroborating evidence of their connection.
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Haystack Observatory
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DOI of Published Version
https://doi.org/10.1029/2021ja029879
