TY - JOUR
T1 - Observation and Simulation of the Development of Equatorial Plasma Bubbles
T2 - Post-Sunset Rise or Upwelling Growth?
AU - Chou, Min Yang
AU - Pedatella, N. M.
AU - Wu, Qian
AU - Huba, J. D.
AU - Lin, Charles C.H.
AU - Schreiner, W. S.
AU - Braun, J. J.
AU - Eastes, R. W.
AU - Yue, Jia
N1 - Funding Information:
This research is supported by National Science Foundation grant AGS‐1522830. This material is based upon work supported by the National Center for Atmospheric Research, which is a major facility sponsored by the National Science Foundation under Cooperative Agreement No. 1852977. The research of J. D. H. was supported by NASA grant NNH17ZDA001N and NSF grant AGS‐1931415. The research of R. W. E. was supported by NASA contract 80GSFC18C0061.
Publisher Copyright:
©2020. American Geophysical Union. All Rights Reserved.
PY - 2020/12
Y1 - 2020/12
N2 - This study investigates the underlying physics of equatorial plasma bubbles (EPBs) on 11 December 2019, under solar minimum conditions. The Global-scale Observations of the Limb and Disk (GOLD) ultraviolet nightglow images exhibit a periodic distribution of reduced emissions related to EPBs. Remarkably, FORMOSAT-7/COSMIC-2 (F7/C2) observes a significant altitudinal difference of ~45 km in the bottomside ionosphere between two nearly collocated electron density profiles before the onset of EPBs, indicating the presence of an upwelling. Distinct ionospheric perturbations are also observed in F7/C2 and ground-based Global Positioning System observations, suggesting that gravity waves may contribute to the upwelling. Simulations with SAMI3/ESF are further carried out to evaluate the upwelling growth and pre-reversal enhancement (PRE) effect on EPB development. Simulations reveal that the crests of upwellings show a localized uplift of ~50 km, and EPBs only develop from the crest of upwellings. The uplift altitude of upwellings is comparable to the F7/C2 observations and the post-sunset rise in moderate solar conditions. The polarization electric field (Ep) developed within the upwellings can drive vertical Ep × B drifts of ~32–35 m/s, which are comparable to the PRE vertical E × B drifts. We find that the PRE alone cannot drive EPBs without upwelling growth, but it can facilitate the upwelling growth. Observations and simulations allow us to conclude that upwelling growth could play a vital role in the formation of EPBs.
AB - This study investigates the underlying physics of equatorial plasma bubbles (EPBs) on 11 December 2019, under solar minimum conditions. The Global-scale Observations of the Limb and Disk (GOLD) ultraviolet nightglow images exhibit a periodic distribution of reduced emissions related to EPBs. Remarkably, FORMOSAT-7/COSMIC-2 (F7/C2) observes a significant altitudinal difference of ~45 km in the bottomside ionosphere between two nearly collocated electron density profiles before the onset of EPBs, indicating the presence of an upwelling. Distinct ionospheric perturbations are also observed in F7/C2 and ground-based Global Positioning System observations, suggesting that gravity waves may contribute to the upwelling. Simulations with SAMI3/ESF are further carried out to evaluate the upwelling growth and pre-reversal enhancement (PRE) effect on EPB development. Simulations reveal that the crests of upwellings show a localized uplift of ~50 km, and EPBs only develop from the crest of upwellings. The uplift altitude of upwellings is comparable to the F7/C2 observations and the post-sunset rise in moderate solar conditions. The polarization electric field (Ep) developed within the upwellings can drive vertical Ep × B drifts of ~32–35 m/s, which are comparable to the PRE vertical E × B drifts. We find that the PRE alone cannot drive EPBs without upwelling growth, but it can facilitate the upwelling growth. Observations and simulations allow us to conclude that upwelling growth could play a vital role in the formation of EPBs.
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U2 - 10.1029/2020JA028544
DO - 10.1029/2020JA028544
M3 - Article
AN - SCOPUS:85098052391
SN - 2169-9402
VL - 125
JO - Journal of Geophysical Research: Space Physics
JF - Journal of Geophysical Research: Space Physics
IS - 12
M1 - e2020JA028544
ER -