Chemical composition and sources of the high Arctic aerosol relevant for cloud formation
Chemical composition and sources of the high Arctic aerosol relevant for cloud formation
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DOI：
10.1029/2001jd001463
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发表时间：
2002-06-01
影响因子：
4.4
通讯作者：
Hillamo, R
中科院分区：
文献类型：
--
作者：
Leck, C;Norman, M;Hillamo, R
[1] 研究了夏季覆盖北冰洋的浮冰上空的云凝结核（CCN）的化学成分、来源和产生方法。空气在浮冰上行进 2 天后，确定了两个当地的 CCN 来源：来自浮冰（薄膜和喷射液滴）之间开放水域破裂气泡的颗粒，以及通过获取二甲硫醚的氧化产物而达到 CCN 尺寸的颗粒。 The bubble-derived particle modes were found to have an exponential dependence on prevailing wind speed.与开放水域上的颗粒相比，薄膜滴的产生对风速的依赖程度较小，而喷射滴的产生对风速的依赖程度更大。然而，风速为 12 m s(-1) 时薄膜滴颗粒的存在增强，在质量和数量上均占主导地位。喷射下降模式主要由海盐组成，对于风速 > 5 m s(-1) 已经产生了显着的质量贡献。然而，较小尺寸的喷射液滴并不是纯氯化钠，而是含有多种且明显的有机成分。在最常见的风速为 5-12 m s(-1) 时，含硫颗粒在 CCN 数量和质量中占主导地位。测得的 CCN 浓度平均低于根据硫酸盐或海盐组合物以及观察到的粒度分布所预期的浓度。结论是其他成分，可能是有机成分，抑制了颗粒的成核能力。然而，在晴朗的天气里，大多数情况下 CCN 浓度都高于根据硫酸盐成分和测量的尺寸分布预测的浓度。
[1] The chemical composition, sources, and methods of production of cloud condensation nuclei (CCN) were studied over the pack ice covered Arctic Ocean in summer. After 2 days' travel of air over the pack ice, two local CCN sources were identified: particles derived from the bursting bubbles on open water between ice floes (film and jet drops) and particles reaching CCN size by acquisition of oxidation products of dimethyl sulfide. The bubble-derived particle modes were found to have an exponential dependence on prevailing wind speed. The film drop generation depended less on wind speed and jet drop production depended more on wind speed than particles over open water did. However, the enhanced presence of film drop particles at wind speeds 12 m s(-1) to dominate both mass and number. The jet drop mode was composed largely of sea salt, making a significant mass contribution already for wind speeds >5 m s(-1). However, the smaller-sized jet drops were not pure sodium chloride but contained a varied and appreciable organic component. The sulfur-containing particles dominated the CCN population and mass for the most common wind speeds of 5-12 m s(-1). Measured CCN concentrations were on average less than would have been expected from either a sulfate or a sea-salt composition and the observed particle-size distribution. It is concluded that other components, probably organic, depressed the nucleating ability of the particles. However, on clear sky days, there were a majority of occasions on which CCN concentrations were more than predicted from a sulfate composition and the measured size distribution.