Mass Spectrometry Measurements of the Size-Resolved Single Particle Mixing State of Atmospheric Aerosols and Ice and Cloud Nuclei During ICE-L

云中冰实验层(ICE-L)野外研究将于2007年秋季在美国国家科学基金会C-130飞机上进行，以测试冰成核测量和其他气溶胶特性是否可以用来预测云中冰粒子的成核。气溶胶飞行时间质谱仪(A-ATOFMS)将被用来表征气溶胶在活动期间的尺寸分辨混合状态，以确定气溶胶混合状态、冰核和冰晶数浓度之间是否存在因果关系。A-ATOFMS提供了有关空气动力学尺寸和尺寸在80-2000纳米之间的单个颗粒的化学成分的信息。它将直接对周围的气溶胶以及飞机上逆流虚拟撞击器(CVI)的残余核进行采样，以比较云外和间隙气溶胶与云核和冰核的化学成分。包括粉尘、金属、烟尘、海盐、有机碳和次生物种在内的耐火和非耐火元素都可以测量。这些发现将指导实验室研究，重点关注一系列不同反应的尘埃颗粒的冰核活动的可变性。反过来，实验室研究的结果将被用于模式参数化，并与冰-L数据进行比较，以确定是否可以从测量的云和气溶胶的微物理和化学特性中获得更准确的冰晶浓度预测。研究生和本科生将接受化学、物理、大气科学和仪器开发方面的培训。将开发一个突出这些研究的网页，并在桦树水族馆公开展示冰云以及它们如何在大气中形成并影响气候。展览的一部分将是流动的，并带到当地学校。该项目将帮助教育公众了解人为排放和气雾剂的性质如何影响区域和全球气候。

The Ice in Clouds Experiment-Layer (ICE-L) field study will be performed in fall 2007 on the NSF C-130 aircraft, to test whether ice nucleation measurements and other aerosol properties can be used to predict ice particle nucleation in clouds. An aerosol time-of-flight mass spectrometer (A-ATOFMS) will be used to characterize the size-resolved mixing state of aerosols during the campaign, in order to determine whether there is a causal relationship between aerosol mixing state, ice nuclei, and ice crystal number concentrations. The A-ATOFMS provides information on the aerodynamic size and chemical composition of individual particles with sizes between 80-2000 nm. It will directly sample ambient aerosols, as well as residual nuclei from a counterflow virtual impactor (CVI) on the aircraft, to compare the chemistry of out-of-cloud and interstitial aerosols with cloud and ice nuclei. Both refractory and non-refractory elements including dust, metals, soot, sea salt, organic carbon, and secondary species can be measured. The findings will guide lab studies that focus on the variability of ice nucleation activity for a range of heterogeneously reacted dust particles. In turn, the findings from the lab studies will be used in model parameterizations to be compared with ICE-L data to determine whether more accurate predictions of ice crystal concentrations can be achieved from measured microphysical and chemical properties of clouds and aerosols. Graduate and undergraduate students will be trained in chemistry, physics, atmospheric science, and instrument development. A web page highlighting these studies will be developed as well as a public exhibit at the Birch Aquarium focusing on ice clouds and how they form in the atmosphere and impact climate. A portion of the exhibit will be mobile and taken to local schools. The project will be to help educate the public on how anthropogenic emissions and the nature of aerosols can impact climate both regionally and globally.