Nightside Detection of a Large-Scale Thermospheric Wave Generated by a Solar Eclipse

B. J. Harding, D. P. Drob, R. A. Buriti, J. J. Makela

Research output: Contribution to journalArticlepeer-review

Abstract

The generation of a large-scale wave in the upper atmosphere caused by a solar eclipse was first predicted in the 1970s, but the experimental evidence remains sparse and comprises mostly indirect observations. This study presents observations of the wind component of a large-scale thermospheric wave generated by the 21 August 2017 total solar eclipse. In contrast with previous studies, the observations are made on the nightside, after the eclipse ended. A ground-based interferometer located in northeastern Brazil is used to monitor the Doppler shift of the 630.0-nm airglow emission, providing direct measurements of the wind and temperature in the thermosphere, where eclipse effects are expected to be the largest. A disturbance is seen in the zonal and meridional wind which is at or above the 90% significance level based on the measured 30-day variability. These observations are compared with a first principles numerical model calculation from the Thermosphere-Ionosphere-Mesosphere-Electrodynamics General Circulation Model, which predicted the propagation of a large-scale wave well into the nightside. The modeled disturbance matches well the difference between the wind measurements and the 30-day median, though the measured perturbation (∼60 m/s) is larger than the prediction (38 m/s) for the meridional wind. No clear evidence for the wave is seen in the temperature data, however.

Original languageEnglish (US)
Pages (from-to)3366-3373
Number of pages8
JournalGeophysical Research Letters
Volume45
Issue number8
DOIs
StatePublished - Apr 28 2018

Keywords

  • airglow
  • solar eclipse
  • thermosphere
  • thermospheric wave
  • thermospheric wind

ASJC Scopus subject areas

  • Geophysics
  • Earth and Planetary Sciences(all)

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