On the influence of non-LTE effects on OH rotational temperatures

Autor(en)

Stefan Noll, Wolfgang Kausch, Stefan Kimeswenger, Stefanie Unterguggenberger, Amy M. Jones

Abstrakt

OH airglow is an important tracer of the state of the mesopause and its variability at about 87 km, since it is the dominating emission from the upper atmosphere in the optical to near-infrared wavelength regime. A great deal of the world-wide mesopause temperature records are based on OH. Lines of single OH bands are used to derive rotational temperatures, which are expected to be close to the ambient temperature if only lines from the lowest rotational levels are considered. However, establishing a rotational-translational equilibrium requires a sufficient frequency of suitable collisions, since the nascent level population distribution of OH by the hydrogen-ozone reaction is dominated by high rotational levels and radiative transitions can change the level by one quantum at most. At least for the upper parts of the OH emission layer, it is not clear whether this criterion is fulfilled, since the concentration of the crucial quencher O2 is relatively low.

Organisation(en)

Institut für Astrophysik

Externe Organisation(en)

Leopold-Franzens-Universität Innsbruck

Journal

Geophysical Research Abstracts

Band

17

ISSN

1029-7006

Publikationsdatum

03-2015

Peer-reviewed

Ja

ÖFOS 2012

103003 Astronomie, 103004 Astrophysik

Link zum Portal

https://ucrisportal.univie.ac.at/de/publications/on-the-influence-of-nonlte-effects-on-oh-rotational-temperatures(c4480d77-19f8-48e3-981b-34a6d445278a).html