Release of Oxygen Atoms and Nitric Oxide Molecules from the Ultraviolet Photodissociation of Nitrate Adsorbed on Water Ice Films at 100 K

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• 作者：Akihiro Yabushita ; Noboru Kawanaka ; Masahiro Kawasaki ; Paul D. Hamer ; Dudley E. Shallcross
• 刊名：Journal of Physical Chemistry A
• 出版年：2007
• 出版时间：September 6, 2007
• 年：2007
• 卷：111
• 期：35
• 页码：8629 - 8634
• 全文大小：204K
• 年卷期：v.111,no.35(September 6, 2007)
• ISSN：1520-5215

文摘

Production of O(³P_J, J = 2, 1, 0) atoms from the 295-320 nm photodissociation of NO₃^- adsorbed on waterpolycrystalline ice films at 100 K was directly confirmed using the resonance-enhanced multiphoton ionizationtechnique. Detection of the O atom signals required an induction period after deposition of HNO₃ onto theice film held at 130 K due to the slow ionization rate of HNO₃ to H⁺ and NO₃^- with a rate constant of k =(5.3 ± 0.2) × 10^-3 s^-1. Translational energy distributions of the O atoms were represented by a combinationof two Maxwell-Boltzmann energy distributions with translational temperatures of 2000 and 100 K. Directdetection of NO from the secondary photodissociation process was also successful. On the atmosphericimplications, the influence of the direct release of the oxygen atoms into the air from NO₃^- adsorbed on thenatural snowpack was included in an atmospheric model calculation on the mixing ratios of ozone and nitricoxide at the South Pole, and the results compared favorably with the field data.