Single Particle Laser Mass Spectrometry Applied to Differential Ice Nucleation Experiments at the AIDA Chamber
Single Particle Laser Mass Spectrometry Applied to Differential Ice Nucleation Experiments at the AIDA Chamber
复制标题
单粒子激光质谱法应用于 AIDA 室的微分冰核实验
DOI：
10.1080/02786820802339538
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发表时间：
2008
影响因子：
5.2
通讯作者：
D. Cziczo
中科院分区：
文献类型：
--
作者：
S. Gallavardin;K. Froyd;U. Lohmann;O. Moehler;D. Murphy;D. Cziczo
在位于德国卡尔斯鲁厄的大气气溶胶相互作用和动力学 (AIDA) 室进行的实验可以研究在与云微物理和气候问题相关的温度和水蒸气条件下影响冰成核的颗粒特性。冰云是由亚利桑那试验尘埃（ATD）、伊利石和赤铁矿的异质成核以及硫酸的均质成核产生的。使用泵送逆流虚拟冲击器 (PCVI) 将室内形成的冰晶与未激活的或“间隙”气溶胶颗粒惯性分离，然后蒸发。使用激光电离质谱仪在单颗粒水平上对冰残留物（即引发冰成核的气溶胶加上从气相和/或颗粒相中清除的任何材料）进行化学表征。以这种方式，可以从室中的混合气溶胶群体中识别出第一个成核冰的种类。裸露的矿物尘埃颗粒比具有涂层的类似颗粒更有效的冰核（IN）。室内污染产生的金属颗粒先于其他物种引发了冰核，但数量足够少，不会影响实验。硝酸盐、硫酸盐和有机物经常在颗粒和冰残渣上检测到，显然是由于室内微量气相物质的清除所致。赤铁矿是比伊利石更有效的冰核。由于清除、污染气体的冷凝以及较大气溶胶在成核过程中占主导地位而形成聚集体，冰残渣通常大于未活化的测试气溶胶。
Experiments conducted at the Aerosol Interactions and Dynamics in the Atmosphere (AIDA) chamber located in Karlsruhe, Germany permit investigation of particle properties that affect the nucleation of ice at temperature and water vapor conditions relevant to cloud microphysics and climate issues. Ice clouds were generated by heterogeneous nucleation of Arizona test dust (ATD), illite, and hematite and homogeneous nucleation of sulfuric acid. Ice crystals formed in the chamber were inertially separated from unactivated, or “interstitial” aerosol particles with a pumped counterflow virtual impactor (PCVI), then evaporated. The ice residue (i.e., the aerosol which initiated ice nucleation plus any material which was scavenged from the gas- and/or particle-phase), was chemically characterized at the single particle level using a laser ionization mass spectrometer. In this manner the species that first nucleated ice could be identified out of a mixed aerosol population in the chamber. Bare mineral dust particles were more effective ice nuclei (IN) than similar particles with a coating. Metallic particles from contamination in the chamber initiated ice nucleation before other species but there were few enough that they did not compromise the experiments. Nitrate, sulfate, and organics were often detected on particles and ice residue, evidently from scavenging of trace gas-phase species in the chamber. Hematite was a more effective ice nucleus than illite. Ice residue was frequently larger than unactivated test aerosol due to the formation of aggregates due to scavenging, condensation of contaminant gases, and the predominance of larger aerosol in nucleation.