Direct Online Mass Spectrometry Measurements of Ice Nucleating Particles at a California Coastal Site
Direct Online Mass Spectrometry Measurements of Ice Nucleating Particles at a California Coastal Site
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DOI：
10.1029/2019jd030466
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发表时间：
2019-11-19
影响因子：
4.4
通讯作者：
Prather, K. A.
中科院分区：
文献类型：
--
作者：
Cornwell, G. C.;McCluskey, C. S.;Prather, K. A.
云中冰的形成会强烈影响云的特性和风暴期间的降水过程，包括大气河流。与矿物粉尘相比，海洋喷雾气溶胶（SSA）颗粒作为冰成核颗粒（INPs）相对低效。然而，由于海洋覆盖了地球表面，最近的一些研究集中在确定海洋INPs的来源，特别是在缺乏强烈的灰尘影响的地区。本研究描述了一种系统的集成、验证和应用，该系统将连续流扩散室与单粒子质谱仪耦合，使用泵送逆流虚拟撞击器去除无核粒子并选择性地测量INPs的组成，检测效率为3.10 × 10（-4）。在现场测量浸没冻结INP组成在加州沿海网站使用集成系统。矿尘颗粒是最丰富的冰晶残留类型在采样期间，发现冰活跃，尽管经历了大气处理。SSA在环境测量中更丰富，但在-31摄氏度下仅代表冰晶残留群体的一小部分。值得注意的是，被激活的SSA颗粒富含可能从海洋转移的有机氮物种。冰核活性位点密度的计算与以前的矿物粉尘和SSA的研究吻合得很好。
The formation of ice in clouds can strongly impact cloud properties and precipitation processes during storms, including atmospheric rivers. Sea spray aerosol (SSA) particles are relatively inefficient as ice nucleating particles (INPs) compared to mineral dust. However, due to the vast coverage of the Earth's surface by the oceans, a number of recent studies have focused on identifying sources of marine INPs, particularly in regions lacking a strong influence from dust. This study describes the integration, validation, and application of a system coupling a continuous flow diffusion chamber with a single particle mass spectrometer using a pumped counterflow virtual impactor to remove nonnucleated particles and selectively measure the composition of INPs with a detection efficiency of 3.10 x 10(-4). In situ measurements of immersion freezing INP composition were made at a coastal site in California using the integrated system. Mineral dust particles were the most abundant ice crystal residual type during the sampling period and found to be ice active despite having undergone atmospheric processing. SSA were more abundant in ambient measurements but represented only a minor fraction of the ice crystal residual population at -31 degrees C. Notably, the SSA particles that activated were enriched with organic nitrogen species that were likely transferred from the ocean. Calculations of ice nucleation active site densities were within good agreement with previous studies of mineral dust and SSA.