Equatorial electrodynamics and neutral background in the Asian sector during the 2009 stratospheric sudden warming

Huixin Liu, Mamoru Yamamoto, S. Tulasi Ram, Takuya Tsugawa, Yuichi Otsuka, Claudia Stolle, Eelco Doornbos, Kiyohumi Yumoto, Tsutomu Nagatsuma

Research output: Contribution to journalArticle

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Abstract

Using ground observations of total electron content (TEC) and equatorial electrojet (EEJ) in the Asian sector, along with plasma and neutral densities obtained from the CHAMP satellite, we investigate the ionospheric electrodynamics and neutral background in this longitude sector during the major stratospheric sudden warming (SSW) in January 2009. Our analysis reveals the following prominent features. First, the TEC response in tropical regions is strongly latitude dependent, with monotonic depletion at the dip equator but a semidiurnal perturbation at low latitudes. Second, the TEC semidiurnal perturbation possesses a significant hemispheric asymmetry in terms of onset date and magnitude. It starts on the same day as the SSW peak in the Northern Hemisphere but 2 days later in the Southern Hemisphere. Its magnitude is twice as strong in the north than in the south. Third, strong counter electrojet occurs in the afternoon, following the strengthening of the eastward EEJ in the morning. Fourth, semidiurnal perturbation in both TEC and EEJ possesses a phase shift, at a rate of about 0.7 h/day. Comparisons with results reported in the Peruvian sector reveal clear longitude dependence in the amplitude and hemispheric asymmetry of the semidiurnal perturbation. Finally, thermospheric density undergoes ∼25% decrease at low latitudes in the afternoon local time sector during the SSW, indicating significant cooling effects in the tropical upper thermosphere.

Original languageEnglish
Article numberA08308
JournalJournal of Geophysical Research: Space Physics
Volume116
Issue number8
DOIs
Publication statusPublished - Jan 1 2011

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Upper atmosphere
electrojet
electrodynamics
Electrodynamics
equatorial electrojet
sectors
tropical regions
electrons
perturbation
heating
Electrons
longitude
asymmetry
electrojets
CHAMP
morning
thermosphere
Southern Hemisphere
Northern Hemisphere
equators

All Science Journal Classification (ASJC) codes

  • Geophysics
  • Forestry
  • Oceanography
  • Aquatic Science
  • Ecology
  • Water Science and Technology
  • Soil Science
  • Geochemistry and Petrology
  • Earth-Surface Processes
  • Atmospheric Science
  • Earth and Planetary Sciences (miscellaneous)
  • Space and Planetary Science
  • Palaeontology

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Equatorial electrodynamics and neutral background in the Asian sector during the 2009 stratospheric sudden warming. / Liu, Huixin; Yamamoto, Mamoru; Tulasi Ram, S.; Tsugawa, Takuya; Otsuka, Yuichi; Stolle, Claudia; Doornbos, Eelco; Yumoto, Kiyohumi; Nagatsuma, Tsutomu.

In: Journal of Geophysical Research: Space Physics, Vol. 116, No. 8, A08308, 01.01.2011.

Research output: Contribution to journalArticle

Liu, H, Yamamoto, M, Tulasi Ram, S, Tsugawa, T, Otsuka, Y, Stolle, C, Doornbos, E, Yumoto, K & Nagatsuma, T 2011, 'Equatorial electrodynamics and neutral background in the Asian sector during the 2009 stratospheric sudden warming', Journal of Geophysical Research: Space Physics, vol. 116, no. 8, A08308. https://doi.org/10.1029/2011JA016607
Liu, Huixin ; Yamamoto, Mamoru ; Tulasi Ram, S. ; Tsugawa, Takuya ; Otsuka, Yuichi ; Stolle, Claudia ; Doornbos, Eelco ; Yumoto, Kiyohumi ; Nagatsuma, Tsutomu. / Equatorial electrodynamics and neutral background in the Asian sector during the 2009 stratospheric sudden warming. In: Journal of Geophysical Research: Space Physics. 2011 ; Vol. 116, No. 8.
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