Chemical and mineralogical characterization of ice nucleating particles and ice particle residuals

冰成核颗粒和冰颗粒残留物的化学和矿物学表征

• 批准号: 201774684
• 负责人: Dr. Heinz Bingemer
• 金额: --
• 依托单位: Institut für Atmosphäre und Umwelt (IAU)
• 依托单位国家: 德国
• 项目类别: Research Units
• 财政年份: 2011
• 资助国家: 德国
• 起止时间: 2010-12-31 至 2019-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/201774684?language=en
• 关键词: Chemical; mineralogical; characterization; ice; nucleating

We investigate the abundance, chemical composition and mixing state of atmospheric ice nucleating particles (INP) experimentally, i.e. of such particles that allow the heterogeneous formation of ice in mixed-phase clouds. This information is inevitable to understand the mechanisms of precipitation in the atmosphere. Meteorological models use parameterizations of such data to predict the development of precipitation. INP are rare: only 1 in 10.000 to 1 in 100.000 of atmospheric particles is an INP. We identify and isolate INP from other constituents of air using physical methods, followed by photography, counting and mineralogical analysis of the single particles, using advanced electron microscopy. The INUIT research unit applies several different approaches to distinguish INP from the bulk of other atmospheric particles. The individual particles identified and separated by these different methods are then collected and analyzed by electron microscopy for their size, morphology, mixing state, and chemical composition. Two of the methods (INP counters FINCH and FRIDGE) identify the INP by exposing an aerosol sample to subzero temperatures and supersaturated water vapor, thus growing macroscopic ice crystals on the INP. Ice crystals and thus INP are then separated from aerosol, and INP analyzed. The INP counter FINCH grows ice crystals on ambient aerosol in a flow tube reactor, while the INP counter FRIDGE grows ice on atmospheric particles that were precipitated electrostatically on a silicon substrate. Two other methods, named Ice-CVI and ISI, attempt to isolate INP by first separating the ice crystals in a flow of accelerated cloud air from other constituents, based on their higher inertia, and then evaporate the ice, leaving the INP behind for subsequent collection and analysis. Results from all four methods are compared. Aerosols from various atmospheric environments (central Europe, Jungfraujoch, Mediterranean, desert dust) will be analyzed during field experiments. Model and standard aerosols will be investigated in lab experiments. The number concentration of INP in the deposition and immersion modes in ambient air at Taunus Observatory near Frankfurt will be analyzed routinely in years 1-3 and screened for a seasonality, potential source areas (desert, industry), and for the main factors or components (such as biological material, mineral dust) that determine its variability.

我们通过实验研究了大气冰成核颗粒（INP）的丰度、化学成分和混合状态，即允许混合相云中冰异质形成的此类颗粒。这些信息对于了解大气中降水的机制是不可避免的。气象模型使用这些数据的参数化来预测降水的发展。 INP 非常罕见：只有万分之一到十万分之一的大气颗粒物是 INP。我们使用物理方法从空气中的其他成分中识别并分离 INP，然后使用先进的电子显微镜对单个颗粒进行摄影、计数和矿物学分析。 INUIT 研究单位采用多种不同的方法来区分 INP 和其他大气颗粒。然后收集通过这些不同方法识别和分离的单个颗粒，并通过电子显微镜分析其尺寸、形态、混合状态和化学成分。其中两种方法（INP 计数器 FINCH 和 FRIDGE）通过将气溶胶样品暴露于零下温度和过饱和水蒸气中来识别 INP，从而在 INP 上生长宏观冰晶。然后将冰晶和 INP 从气溶胶中分离出来，并对 INP 进行分析。 INP 计数器 FINCH 在流管反应器中的环境气溶胶上生长冰晶，而 INP 计数器 FRIDGE 在静电沉淀在硅基板上的大气颗粒上生长冰晶。另外两种方法，即 Ice-CVI 和 ISI，试图通过首先将加速云空气流中的冰晶与其他成分分离（基于其较高的惯性）来分离 INP，然后蒸发冰，留下 INP 以供后续收集和分析。比较所有四种方法的结果。来自各种大气环境（中欧、少女峰、地中海、沙漠尘埃）的气溶胶将在现场实验中进行分析。模型和标准气溶胶将在实验室实验中进行研究。 法兰克福附近的陶努斯天文台环境空气中沉积和浸没模式的 INP 数量浓度将在第 1-3 年进行例行分析，并筛选季节性、潜在源区（沙漠、工业）以及决定其变化的主要因素或成分（例如生物材料、矿物粉尘）。