Comment on "The diffuse aurora: A significant source of ionization in the middle atmosphere" by R. A. Frahm et al

• Published in: Journal of Geophysical Research, Washington, DC Washington, DC, 2000-06, Vol.105 (D12), p.15681-15684
• Main Author: Callis, Linwood B.
• Format: Article
• Language: English
• Subjects: Earth, ocean, space; Exact sciences and technology; External geophysics; General properties of the high atmosphere; Physics of the high neutral atmosphere
• ISSN: 0148-0227; 2156-2202
• DOI: 10.1029/2000JD900117

The paper by Frahm et al. [1997], hereinafter referred to as F97, discussed the use of the Particle Environment Monitor (PEM) electron data to calculate ionization rates in the middle atmosphere. In that paper the authors also discuss several of our publications [Callis et al., 1991a, b, 1996a, b], hereinafter referred to as C91a, C91b, C96a, and C96b. These publications have discussed energetic electron precipitation from the auroral and trapping regions of the magnetosphere with emphasis on the resultant odd nitrogen (NO sub(y) ) formation in the mesosphere and the lower thermosphere, and the possibility that the NO sub(y) is transported into the stratosphere where the O sub(3) budget may be affected. In the characterization of results in these papers by F97, there are factual errors as well as errors of interpretation. In this commentary, these errors are addressed. I also question the importance, suggested by F97, of ionization due to bremsstrahlung X-ray radiation to the local formation of HNO sub(3) , through ion chemistry, below 50 km and its role in the formation of the secondary maximum in HNO sub(3) .