All Physics Faculty Publications

Title

The Impact of L-uncoupling on Einstein Coefficients forthe OH Meinel (6,2) Band: Implications For Q-branch Rotational Temperatures

Document Type

Article

Journal/Book Title/Conference

Journal of Atmospheric and Solar-Terrestrial Physics

Volume

64

Issue

8-11

Publisher

Elsevier

Publication Date

5-2002

First Page

971

Last Page

983

DOI

10.1016/S1364-6826(02)00051-2

Abstract

A recent high-precision study of the J-dependent rovibrational branching in the aeronomically important OH Meinel (M) (6,2) band has demonstrated that the available theoretical and semiempirical Einstein coefficients fail to adequately describe the branching, especially in the case of ΔJ=0 (Q-branch) transitions. We suggest that the heterogeneous perturbation associated with rotational-electronic mixing of the X and A states (L-uncoupling) is the primary source of this disparity. In support of this hypothesis, perturbation-theory calculations, based on an accurate, experimentally verified, ab initio AX electric dipole moment function, have yielded rovibrational branching in good accord with experiment. Further, we show that OH M (6,2) Q-branch-based determinations of rotational temperatures and band emission rates contain significant systematic errors irrespective of the specific choice of theoretical/semiempirical A coefficients used in the analyses. Thus, these new results have special implications for the interpretation of M (6,2) Q-branch data, e.g. that obtained with the Spectral Airglow Temperature Imagers which were recently developed as part of the Planetary Scale Mesopause Observing System Project.

Comments

Published by Elsevier in Journal of Atmospheric and Solar-Terrestrial Physics.

http://www.sciencedirect.com/science/article/pii/S1364682602000512

Publisher PDF is available for download through the link above.

http://www.sciencedirect.com/science/article/pii/S1364682602000512