Frost flowers: Implications for tropospheric chemistry and ice core interpretation
Frost flowers: Implications for tropospheric chemistry and ice core interpretation
复制标题
DOI：
10.1029/2002jd002492
复制
发表时间：
2002-12
影响因子：
--
通讯作者：
A. Rankin;E. Wolff;Seelye Martin
中科院分区：
文献类型：
--
作者：
A. Rankin;E. Wolff;Seelye Martin
[1]本文讨论了霜花的化学成分及其伴随的雪泥层，以及它们在对大气化学和冰芯解释重要的过程中作为盐源的作用的证据。对南极霜花的分析表明，它们是高度含盐的，并在海盐离子中分离，硫酸盐相对于钠强烈耗尽。由于霜花在卫星散射仪图像上有明亮的反射，因此可以确定它们形成的时间和地点。当风从散射仪识别为被花覆盖的区域吹向气溶胶采样站时，所收集的气溶胶中的硫酸盐也被耗尽。由于花有一个大的盐度，溴化物浓度升高，在霜花相对于海水。由于其表面积大，溴有可能从霜花中释放到大气中，从而对对流层臭氧消耗产生影响。在冬季的海冰界面上有大量的分馏海盐，并可能以气溶胶的形式被输送到内陆，这一发现也对冰芯记录的解释产生了影响。对一个近海岸岩芯的分析表明，大部分钠来自分馏源，而不是来自开放水域。冰芯中强烈的海盐信号被归因于开放水域的增加和内陆运输的更有效，这可能是由于暴风雨天气。然而，至少在沿海地区，这些信号可能与海冰和霜花的形成增加有关。
[1] This paper discusses the chemical composition of frost flowers and their accompanying slush layers and the evidence for their role as a salt source in processes important to atmospheric chemistry and ice core interpretation. Analysis of Antarctic frost flowers shows that they are highly saline and fractionated in sea-salt ions, with sulfate being depleted strongly relative to sodium. Because frost flowers give a bright return on satellite scatterometer images, the times and places of their formation can be identified. When winds blow towards an aerosol sampling station from areas identified by the scatterometer as covered with flowers, the collected aerosol is also depleted in sulfate. Because the flowers have a large salinity, bromide concentrations are elevated in frost flowers relative to seawater. With their high surface area, it is possible that bromine is released to the atmosphere from frost flowers, with consequent implications for tropospheric ozone depletion. The finding that quantities of fractionated sea salt are available at the sea–ice interface in the winter months and may be transported inland as aerosol also has implications for the interpretation of ice core records. Analysis of one near-coastal core shows that the majority of the sodium comes from a fractionated source rather than from open water. Hitherto, strong sea-salt signals in ice cores have been attributed to increased open water and more efficient transport inland, perhaps due to stormier weather. At least in coastal regions, however, these signals may be related instead to the increased formation of sea ice and frost flowers.