Open AccessAuroral effects on the gas phase chemistry of meteoric sodium
Author(s) -
Heinselman Craig J.
Publication year - 2000
Publication title -
journal of geophysical research: atmospheres
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.67
H-Index - 298
eISSN - 2156-2202
pISSN - 0148-0227
DOI - 10.1029/2000jd900085
Subject(s) - ionization , sodium , atmosphere (unit) , gas phase , phase (matter) , energetic neutral atom , atom (system on chip) , atomic physics , ion , flux (metallurgy) , chemistry , meteorology , physics , organic chemistry , computer science , embedded system
The effects of auroral ionization on the gas phase chemistry of meteoric sodium in the upper atmosphere are considered via computer simulation and with a case study. We find that under some circumstances, auroral ionization can significantly affect the chemical state of sodium. In particular, at auroral altitudes, where recently deposited material or sudden atom layers are typically found, neutral Na can be ionized via charge transfer reactions with aurorally enhanced ionization products. The time constants for these reactions are of the order of 15 min. Measurements collected at the Sondrestrom Facility, in Greenland, are analyzed, and a case study is presented for which this gas phase chemistry is sufficient to explain the results. In addition to supporting the predicted influence of auroral ionization on neutral sodium, this case study is also consistent with a chemical mechanism for the formation of a sporadic atom layer.