Hemispheric asymmetry in transition from equatorial plasma bubble to blob as deduced from 630.0 nm airglow observations at low latitudes
Abstract
Transitions from depletions to enhancements of 630.0 nm nighttime airglow have been observed at Arecibo. Numerical simulations by Krall et al. (2009) predicted that they should occur only in one hemisphere, which has not yet been confirmed observationally. In this study we investigate the hemispheric conjugacy of the depletion‐to‐enhancement transition using multiple instruments. We focus on one event observed in the American longitude sector on 22 December 2014: 630.0 nm airglow depletions evolved into enhancements in the Northern Hemisphere while the evolution did not occur in the conjugate location in the Southern Hemisphere. Concurrent plasma density measured by low Earth orbit (LEO) satellites and 777.4 nm airglow images support that the depletions and enhancements of 630.0 nm nighttime airglow reflect plasma density decreases and increases (blobs), respectively. Characteristics of the airglow depletions, in the context of the LEO satellite data, further suggest that the plasma density depletion deduced from the airglow data represents equatorial plasma bubbles (EPBs) rather than medium‐scale traveling ionospheric disturbances from midlatitudes. Hence, the event in this study can be interpreted as EPB‐to‐blob transition.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Jan 01, 2016
- Source ID
- 10.1002/2015ja022175
Entities
People
- Carlos R. Martinis
- H. Lühr
- Jaeheung Park
- Robert F. Pfaff
- Young‐sil Kwak
Organizations
- Air Force Research Laboratory
- Boston University
- Goddard Space Flight Center
- Korea Astronomy and Space Science Institute
- National Science Foundation
- Office of Naval Research