Nighttime medium scale traveling ionospheric disturbances in southern hemisphere using FORMOSAT-2/ISUAL 630.0 nm airglow images
Abstract
In this work characteristics of nighttime medium-scale travelling ionospheric disturbances (MSTID) are investigated using 630.0 nm limb images by Imager of Sprites and Upper Atmospheric Lightnings (ISUAL), onboard FORMOSAT-2 satellite. The limb integrated measurements, when projected to a horizontal plane, reveal bands of intensity perturbation with distinct southwest to northeast orientation in the southern hemisphere. Airglow simulations are carried out by artificially introducing MSTID fluctuations in model electron density to confirm if such azimuthally oriented features could be identified in the ISUAL viewing geometry. Further statistical analysis shows more MSTID occurrence in solstices with peak in June-July months. The wavelengths of the observed perturbations were in the range 150-300 km. The wave fronts were oriented about 30°-50° from the east-west plane, indicating that coupled Perkins and Es-layer instability might be important in the MSTID generation. The results demonstrate that space based airglow imaging is an effective method for global investigation of MSTID events that are appropriately aligned with the viewing geometry.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2017
- Bibcode:
- 2017AGUFMSA42A..07R
- Keywords:
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- 2427 Ionosphere/atmosphere interactions;
- IONOSPHERE;
- 2437 Ionospheric dynamics;
- IONOSPHERE;
- 2443 Midlatitude ionosphere;
- IONOSPHERE