First Simultaneous Lidar Observations of Thermosphere-Ionosphere Fe and Na (TIFe and TINa) Layers at McMurdo (77.84 degrees S, 166.67 degrees E), Antarctica With Concurrent Measurements of Aurora Activity, Enhanced Ionization Layers, and Converging Electric Field

• Published in: Geophysical Research Letters
• Main Authors: Chu, Xinzhao, Nishimura, Yukitoshi, Xu, Zhonghua, Yu, Zhibin, Plane, John M. C., Gardner, Chester S., Ogawa, Yasunobu
• Other Authors: Electrical and Computer Engineering
• Format: Article in Journal/Newspaper
• Language: English
• Published: 2020
• Subjects: Antarc*; Antarctic; Antarctica; Antarctica New Zealand; E. Antarctica; United States Antarctic Program
• Online Access: http://hdl.handle.net/10919/101009; https://doi.org/10.1029/2020GL090181

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 similar to 384 cm(-3) and the TIFe mixing ratio peaks around 123 km, similar to 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. National Science Foundation (NSF)National Science Foundation (NSF) [OPP-1246405, OPP-1443726]; NSFNational Science Foundation (NSF) [ANT-1643700, AGS-1907698]; Japanese Antarctic Research Expedition program; National Aeronautics and Space Administration (NASA)National Aeronautics & Space Administration (NASA) [80NSSC18K0657]; Air Force Office of Scientific Research (AFOSR)United States Department of DefenseAir Force Office of Scientific Research (AFOSR) [FA9559-16-1-0364]; European Research CouncilEuropean Research Council (ERC) [291332-CODITA] We acknowledge Dongming Chang for lidar data collection during Antarctic winter 2018. We appreciate the staff of United States Antarctic Program, McMurdo Station, Antarctica New Zealand, and Scott Base for their superb support. The McMurdo lidar projects were supported by the National Science Foundation (NSF) grants OPP-1246405 and OPP-1443726. The aurora imager is supported by NSF ANT-1643700 (PI: Dr. Gerrard) and Japanese Antarctic Research ...