Aqueous Phase Reaction of HNO_4: The Impact on Tropospheric Chemistry

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• 作者：Frank Dentener ; Jason Williams and Swen Metzger
• 关键词：heterogeneous chemistry ; HNO4 ; HO2NO2 ; NOx ; peroxynitric acid ; SO2 ; sulphate
• 刊名：Journal of Atmospheric Chemistry
• 出版年：2002
• 出版时间：2002
• 年：2002
• 卷：41
• 期：2
• 页码：109-133
• 全文大小：373 KB
• 刊物类别：Earth and Environmental Science
• 刊物主题：Earth sciences
  Meteorology and Climatology
  Atmospheric Protection, Air Quality Control and Air Pollution
  
• 出版者：Springer Netherlands
• ISSN：1573-0662

文摘

We use a global atmospheric chemistry transport model to study the possible influence of aqueous phase reactions of peroxynitric acid (HNO₄) on the concentrations and budgets of NO_x, SO_x, O₃ and H₂O₂. Laboratory studies have shown that the aqueous reaction of HNO_4aq withHSO–_3aq, and the uni-molecular decomposition of the NO₄– anion to form NO₂– (nitrite) occur on a time scale of about a second. Despite a substantial contribution of the reaction of HSO–_3aq with HNO_4aq to the overall in-cloud conversion of SO₂ to SO₄2–, a simultaneous decrease of other oxidants (most notably H₂O₂) more than compensated the increase in SO₄2– production. The strongest influence of heterogeneous HNO₄ chemistry was found in the boundary layer, where calculated monthly average ozone concentrations were reduced between 2% to 10% andchanges of H₂O₂ between –20% to +10%compared to a simulation which ignores this reaction. Furthermore, SO₂ was increased by 10% to 20% and SO₄2–depleted by up to 10%. Since the resolution of our global model does not enable a detailed comparison with measurements in polluted regions, it is not possible to verify whether considering heterogeneous HNO₄ reactions results in a substantial improvement of atmospheric chemistry transport models. However, the conversion of HNO₄ in the aqueous phase seems to be efficient enough to warrant further laboratory investigations and more detailed model studies on this topic.