How does deposition of gas phase species affect pH at frozen salty interfaces
How does deposition of gas phase species affect pH at frozen salty interfaces
复制标题
气相物质的沉积如何影响冷冻盐界面的 pH 值
DOI：
10.5194/acp-12-10065-2012
复制
发表时间：
2012
影响因子：
6.3
通讯作者：
D. Donaldson
中科院分区：
文献类型：
--
作者：
S. Wren;D. Donaldson
摘要。发生在冰雪表面的化学过程在控制上覆大气的氧化能力方面起着重要作用。然而，由于我们对空气-冰界面的化学性质了解不足，对这些过程进行更好的机械理解的努力受到了阻碍。在这里，我们使用了瞄角激光诱导荧光，并结合hammine（一种表面活性的、对pH敏感的荧光染料）来研究冰的性质，无论是冰冻的淡水、盐水还是海水，如何影响表面pH值的变化。HCl(g)的沉积导致冻结淡水表面和冻结咸水表面的pH响应非常不同，这表明这两个表面存在不同的化学环境。重要的是，海冰表面可以缓冲气相物质沉积引起的pH值变化。这些结果对于理解发生在空气-冰边界的ph敏感过程具有重要意义，例如溴活化。
Abstract. Chemical processes occurring on snow and ice surfaces play an important role in controlling the oxidative capacity of the overlying atmosphere. However, efforts to gain a better, mechanistic understanding of such processes are impeded by our poor understanding of the chemical nature of the air-ice interface. Here we use glancing-angle laser induced fluorescence in conjunction with harmine – a surface-active, pH-sensitive fluorescent dye – to investigate how the nature of the ice, whether frozen freshwater, salt water or seawater, influences pH changes at the surface. Deposition of HCl(g) leads to a very different pH response at the frozen freshwater surface than at the frozen salt water surface indicating that these two surfaces present different chemical environments. Importantly, the sea ice surface is buffered against pH changes arising from deposition of gas phase species. These results have important implications for understanding pH-sensitive processes occurring at the air-ice boundary, such as bromine activation.