Mineral Dust - A Key Player in the Earth System
Mineral Dust - A Key Player in the Earth System
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矿物尘埃 - 地球系统的关键角色
DOI：
10.1007/978-94-017-8978-3_12
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发表时间：
2014
期刊：
影响因子：
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通讯作者：
Nenes A
中科院分区：
文献类型：
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作者：
Nenes A
我们对气溶胶和云的相互作用的理解在实验室实验、现场测量和过程建模方面有着深厚的传统。我们提出了一个审查的知识状态，从全球主要粉尘源区排放的矿物粉尘。实验室研究和实地测量使人们对矿物粉尘释放到大气中并与大气成分发生反应的过程和机制有了深入的了解。此外，理论方法和参数化已被建立来解释的观测和定量表达的机制，尘埃可以作为云凝结核（CCN）和冰核（IN）。最后，模式模拟已被用来研究沙尘粒子的影响，以不同的气溶胶-云-气候相互作用。灰尘可以作为有效的云凝结核在云中，仅仅是基于它们相对较大的尺寸，结合其不溶性核心吸附水蒸气的亲水性。当与来自排放或大气处理的甚至小部分吸湿材料混合时，它们的吸湿性和云凝结核活性显著增强。提出了吸附活化和Köhler理论的理论框架来解释尘埃CCN活动，并总结了尘埃对云滴数浓度（CDNC）的潜在贡献及其在调节过饱和度中的作用。矿物尘埃气溶胶是一种有效的IN，结合其浓度，可以主导卷云和混合相云的冰生产，即使在很大的距离从源区。不同的云类型，冰成核的途径是不同的，在这些云中有不同的效果。我们对冰成核的基本理解落后于CCN激活，一个关键的挑战是我们不能先验地预测哪些气溶胶材料将有效地IN。然而，大量的实地和实验室研究表明，沙漠中的矿物粉尘是地球仪周围最重要的冰成核气溶胶类型之一。
Our understanding of the interactions of aerosols and clouds has a strong heritage in laboratory experiments, field measurements, and process modeling. We present a review on the state of knowledge for mineral dust emitted from major global dust source regions. Laboratory studies and field measurements have given insights on processes and mechanisms taking place when mineral dust is released into the atmosphere and reacts with the atmospheric constituents. Furthermore, theoretical approaches and parameterizations have been established to interpret the observations and quantitatively express the mechanisms by which dust can act as cloud condensation nuclei (CCN) and ice nuclei (IN). Finally, model simulations have been used in order to study the effects of dust particles to different aerosol-cloud-climate interactions. Dust can act as efficient CCN in clouds solely based on their relatively large size combined with the hydrophilicity from the adsorption of water vapor on their insoluble core. When mixed with even small fractions of hygroscopic material from emission or atmospheric processing, their hygroscopicity and CCN activity are significantly enhanced. The theoretical frameworks of adsorption activation and Köhler theory are presented to explain dust CCN activity, together with a summary on the potential contributions of dust to cloud droplet number concentration (CDNC), and its role in regulating supersaturation. Mineral dust aerosol is an effective IN and, combined with their concentration, can dominate ice production in cirrus and mixed-phase clouds even at great distances from source regions. The pathways to nucleation of ice are different for different cloud types and have distinct effects in those clouds. Our fundamental understanding of ice nucleation lags behind that for CCN activation, and a key challenge is that we cannot predict a priori which aerosol materials will make effective IN. Nevertheless, numerous field and laboratory studies have shown that mineral dust from deserts is one of the most important ice-nucleating aerosol types around the globe.