Chang, Y, Li, Q, An, F et al. (17 more authors) (2020) Water Photolysis and its Contributions to the Hydroxyl Dayglow Emissions in the Atmospheres of Earth and Mars. Journal of Physical Chemistry Letters. ISSN 1948-7185
Abstract
Airglow is a well-known phenomenon in the Earth’s upper atmosphere, which arises from the emissions of energetic atoms and molecules. The Meinel band emission from high vibrationally excited OH(X) radicals is one of the more important contributors to the airglow from the mesosphere/lower thermosphere. The H + O3 reaction has long been regarded as the dominant source of these OH(X, high v) radicals. Here we demonstrate that vacuum ultraviolet (VUV) photolysis of water vapor at λ ∼ 112.8 nm represents another source of exceptionally highly vibrationally excited OH(X) radicals, with a nascent vibrational state population distribution that maximizes at v = 9 and extends to at least the v = 15 level. Atmospheric chemistry modeling indicates that OH(X, high v) radicals from H2O photolysis might be detectable in the OH Meinel band dayglow in the upper atmosphere of Earth and should dominate the corresponding emission from the Martian atmosphere. VUV photolysis of H2O also produces electronically excited OH(A) radicals, and simultaneous detection of emissions from OH(X, high v) and OH(A) is shown to offer a route to identifying high-oxygen exoplanetary atmospheres.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Dates: |
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Institution: | The University of Leeds |
Academic Units: | The University of Leeds > Faculty of Engineering & Physical Sciences (Leeds) > School of Chemistry (Leeds) > Physical Chemistry (Leeds) The University of Leeds > Faculty of Environment (Leeds) > School of Earth and Environment (Leeds) > National Centre for Atmos Science (NCAS) (Leeds) |
Depositing User: | Symplectic Publications |
Date Deposited: | 16 Oct 2020 14:39 |
Last Modified: | 16 Oct 2020 14:39 |
Status: | Published online |
Publisher: | American Chemical Society |
Identification Number: | 10.1021/acs.jpclett.0c02803 |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:166435 |
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Filename: Supplementary Information_JPCL.pdf

Filename: high vibrational excited OH from water photochemistry_JPCL.pdf
