First Simultaneous Lidar Observations of Thermosphere‐Ionosphere Fe and Na (TIFe and TINa) Layers at McMurdo (77.84°S, 166.67°E), Antarctica With Concurrent Measurements of Aurora Activity, Enhanced Ionization Layers, and Converging Electric Field
Abstract
We report the first simultaneous, common‐volume lidar observations of thermosphere‐ionosphere Fe (TIFe) and Na (TINa) layers in Antarctica. We also report the observational discovery of nearly one‐to‐one correspondence between TIFe and aurora activity, enhanced ionization layers, and converging electric fields. Distinctive TIFe layers have a peak density of ~384 cm−3 and the TIFe mixing ratio peaks around 123 km, ~5 times the mesospheric layer maximum. All evidence shows that Fe+ ion‐neutralization is the major formation mechanism of TIFe layers. The TINa mixing ratio often exhibits a broad peak at TIFe altitudes, providing evidence for in situ production via Na+ neutralization. However, the tenuous TINa layers persist long beyond TIFe disappearance and reveal gravity wave perturbations, suggesting a dynamic background of neutral Na, but not Fe, above 110 km. The striking differences between distinct TIFe and diffuse TINa suggest differential transport between Fe and Na, possibly due to mass separation.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Oct 19, 2020
- Source ID
- 10.1029/2020gl090181
Entities
People
- Chester S Gardner
- John M. C. Plane
- Xinzhao Chu
- Yasunobu Ogawa
- Yukitoshi Nishimura
- Zhibin Yu
- Zhonghua Xu
Organizations
- Air Force Office of Scientific Research
- Boston University
- European Research Council
- Harbin Institute of Technology
- National Aeronautics and Space Administration
- National Institute of Polar Research
- National Science Foundation
- University of Colorado Boulder
- University of Illinois Urbana–Champaign
- University of Leeds
- Virginia Tech