科研之友
微信
新浪微博
Facebook
分享链接
摘要
Nitrite was measured in atmospheric liquid phase samples between 1998 and 2005 to investigate the heterogeneous formation of nitrous acid in the lower atmosphere, as well as to assess the quality of water recovered from dew. The samples were collected during ground-based cloud field experiments at different German mountain sites (Brocken, Schmucke, and Hohenpeissenberg) and at a site south of the Bordeaux urban area (France). Concentrations found in Bordeaux dew samples (up to 2800 mu g 1(-1)) are comparable to those found elsewhere in urban fog and dew water and considerably higher than those detected in cloud water or rain. Particulate nitrite (and nitrate) as well as HNO2 (HNO3) data in air masses from a foothill site of Mt. Schmucke, before involved in cloud processing, are also presented. In clouds at Mt. Brocken, both the interstitial HNO2 gas and the aqueous phase nitrite concentration have been measured simultaneous. Significant deviations from Henry's law have been observed, indicating that a calculation of HNO2 from measured solute nitrite concentrations in bulk samples will overestimate the gasphase concentration. Besides the heterogeneous HNO2 production on wetted surfaces with contact to atmospheric air, a fraction of nitrite measured in cloud droplets or dew will arise from the dissolution of gasphase HNO2, the particle scavenging processes or the dissolution of surface substrates. HNO2 is a dominant hydroxyl radical source during daytime due to its effective photolysis and after water evaporation the released nitrite can significantly contribute to the total OH production and therefore to photochemical smog conditions in the lower atmosphere.
- 出版日期2008-3
- 单位中国地震局
