Explaining Solar Flare‐Induced Ionospheric Ion Upflow at Millstone Hill (42.6°N)
Name
JGR Space Physics - 2022 - Liu - Explaining Solar Flare‐Induced Ionospheric Ion Upflow at Millstone Hill 42 6 N.pdf
Description
Accepted version
Size
2.79 MB
Format
Adobe PDF
Checksum (MD5)
840aff7c5a86ad9ecc34519c5228ede1
Author(s)
Liu, Xuanqing
Liu, Jing
Wang, Wenbin
Zhang, Shun‐Rong
Zhang, Kedeng
Lei, Jiuhou
Liu, Libo
Chen, Xuetao
Li, Shuhan
Zhang, Qing‐He
Date Issued
July 7, 2022
Journal
Journal of Geophysical Research: Space Physics
Publisher
American Geophysical Union
Citation
Liu, X., Liu, J., Wang, W., Zhang, S.-R., Zhang, K., Lei, J., et al. (2022). Explaining solar flare-induced ionospheric ion upflow at Millstone Hill (42.6°N). Journal of Geophysical Research: Space Physics, 127, e2021JA030185.
Version
Final published version
Abstract
Previous studies have shown that solar flares can significantly affect Earth's ionosphere and induce ion upflow with a magnitude of ∼110 m/s in the topside ionosphere (∼570 km) at Millstone Hill (42.61°N, 71.48°W). We use simulations from the Thermosphere-Ionosphere-Electrodynamics General Circulation Model (TIEGCM) and observations from Incoherent Scatter Radar (ISR) at Millstone Hill to reveal the mechanism of ionospheric ion upflow near the X9.3 flare peak (07:16 LT) on 6 September 2017. The ISR observed ionospheric upflow was captured by the TIEGCM in both magnitude and morphology. The term analysis of the F-region ion continuity equation during the solar flare shows that the ambipolar diffusion enhancement is the main driver for the upflow in the topside ionosphere, while ion drifts caused by electric fields and neutral winds play a secondary role. Further decomposition of the ambipolar diffusive velocity illustrates that flare-induced changes in the vertical plasma density gradient is responsible for ion upflow. The changes in the vertical plasma density gradient are mainly due to solar extreme ultraviolet (EUV, 15.5–79.8 nm) induced electron density and temperature enhancements at the F2-region ionosphere with a minor and indirectly contribution from X-ray (0–15.5 nm) and ultraviolet (UV, 79.8–102.7 nm).
MIT Department
Haystack Observatory
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Persistent DSpace Link
DOI of Published Version
https://doi.org/10.1029/2021ja030185
