Size-Dependent Changes in Sea Spray Aerosol Composition and Properties with Different Seawater Conditions
Size-Dependent Changes in Sea Spray Aerosol Composition and Properties with Different Seawater Conditions
复制标题
DOI：
10.1021/es400416g
复制
发表时间：
2013-06-04
影响因子：
11.4
通讯作者：
Grassian, Vicki H.
中科院分区：
文献类型：
--
作者：
Ault, Andrew P.;Moffet, Ryan C.;Grassian, Vicki H.
海洋喷雾气溶胶（SSA）中粒子的化学多样性以及无机和有机粒子之间的混合程度存在很大的不确定性。因此，本研究对SSA颗粒进行单颗粒分析，结合透射电子显微镜与能量色散x射线分析和扫描透射x射线显微镜与近边缘x射线吸收精细结构光谱分析，重点量化30 nm至1 μ m不同颗粒类型的相对分数。SSA颗粒是在独特的海洋大气破碎波设施中从海水中产生的。探讨了添加生物（细菌和浮游植物）和有机物（ZoBell生长培养基）对SSA组成和性能的影响。亚微米SSA颗粒可分为两个不同的种群：一类具有主要由NaCl和有机碳和Mg2+涂层组成的海盐核心（SS-OC）；另一类由有机碳（OC）组成，其中阳离子和阴离子混合更均匀，但不含氯化物。SS-OC颗粒表现出广泛的大小、组成、形态和每个颗粒内元素的分布。在海水中加入生物和有机物后，SS-OC颗粒的形态和结晶行为发生变化，有机质含量增加。oc型颗粒的比例随着生物活性的增加而显著增加，主要存在于180亩以下。这些随大小和海水组成的变化对云滴活化和非均相反应性等大气过程具有重要意义。
A great deal of uncertainty exists regarding the chemical diversity of particles in sea spray aerosol (SSA), as well as the degree of mixing between inorganic and organic species individual SS particles. Therefore, in this study, single particle analysis was performed on SSA particles, integrating transmission electron microscopy with energy dispersive X-ray analysis and scanning transmission X-ray microscopy with near edge X-ray absorption fine structure spectroscopy, with a focus on quantifying the relative fractions of different particle types from 30 nm to 1 mu m. SSA particles were produced from seawater in a unique ocean-atmosphere facility equipped with breaking waves. Changes to the SSA composition and properties after the addition of biological (bacteria and phytoplankton) and organic material (ZoBell growth media) were probed. Submicrometer SSA particles could be separated into two distinct populations: one with a characteristic sea salt core composed primarily of NaCl and an organic carbon and Mg2+ coating (SS-OC), and a second type consisting of organic carbon (OC) species which are more homogeneously mixed with cations and anions, but not chloride. SS-OC particles exhibit a wide range of sizes, compositions, morphologies, and distributions of elements within each particle. After addition of biological and organic material to the seawater, a change occurs in particle morphology and crystallization behavior associated with increasing organic content for SS-OC particles. The fraction of OC-type particles, which are mainly present below 180 mu, becomes dramatically enhanced with increased biological activity. These changes with size and seawater composition have important implications for atmospheric processes such as cloud droplet activation and heterogeneous reactivity.