Premium
First simultaneous measurements of Na and K thermospheric layers along with TILs from Arecibo
Author(s) -
Raizada Shikha,
Brum C. M.,
Tepley C. A.,
Lautenbach Jens,
Friedman J. S.,
Mathews John D.,
Djuth F. T.,
Kerr Caitlin
Publication year - 2015
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1002/2015gl066714
Subject(s) - thermosphere , ion , ionosphere , atmospheric sciences , sporadic e propagation , atomic physics , physics , astrophysics , materials science , geophysics , quantum mechanics
Abstract This work presents the first simultaneous observations of Na and K between 120 and 150 km altitudes along with ionospheric tidal ion layers (TILs) obtained on 30 January 2006 data from Arecibo. The latter displays an average downward phase velocity of ~14.7 ms −1 . However, the neutral layers descend together at a much slower velocity of about ~0.69 ms −1 . This indicates that thermospheric atomic metal layers are not necessarily associated with TILs. The ratio of the average Na/K abundances in thermosphere is ~35.5 as compared to 150 in the main layer (80–105 km). The long lifetimes of ions at ~140 km implies that neutral layers cannot result from direct neutralization of metal ions in the TILs. We investigate different mechanisms that can deposit neutral atoms at thermospheric altitudes.