Sources, Visibility and Climate Effects of Marine Aerosols

海洋气溶胶的来源、能见度和气候影响

• 批准号: RGPIN-2022-04963
• 负责人: Chang, Rachel
• 金额: $ 3.72万
• 依托单位: Dalhousie University
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2022
• 资助国家: 加拿大
• 起止时间: 2022-01-01 至 2023-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=763156
• 关键词: Sources; Visibility; Climate; Effects; Marine

Liquid cloud and fog droplets, like steam from boiling water, form on pre-existing aerosol particles in the atmosphere, and the particle size and chemical composition affect their ability to turn into droplets. The number of particles can affect the reflectivity of a cloud or fog, which affects visibility in a fog or the fraction of sunlight transmitted through a cloud, thus affecting the Earth's energy budget. However, the link between particles, clouds and climate remains poorly constrained. The oceans, including coastal and polar regions, cover 70% of the Earth yet our understanding of the particles and particle precursors (i.e. gases) that they emit into the atmosphere are still highly uncertain as are the ultimate effect of marine particles on climate and visibility through cloud and fog formation. To address this, the proposed work will use a variety of techniques to 1) determine how surface ocean chemical and physical conditions affect the properties of marine aerosol particles in controlled laboratory settings and apply these findings to the ambient marine atmosphere through modelling studies; 2) test fog formation and visibility predictions at northern Canadian coastal locations through an extended crowd-sourced observation network and detailed observational studies; and 3) constrain aerosol-fog/cloud interactions in marine locations by determining the extent to which particle chemical and physical properties affect fog/cloud properties such as droplet concentration, visibility and reflectivity through field and modelling studies. Taken together, this research will improve our understanding of the sources and properties of marine, coastal, and polar aerosols as well as their impact on climate through their ability to activate as cloud droplets. It is expected that this work will directly benefit coastal residents, especially those living in the North, through improved fog predictions. This work will also benefit chemical transport modellers through improved characterization of primary and secondary marine aerosols, and climate modellers by providing sample data sets against which their simulations of aerosol-cloud interactions can be compared.

液态云和雾滴，就像沸水中的蒸汽，形成于大气中预先存在的气溶胶颗粒上，颗粒大小和化学成分影响它们变成液滴的能力。粒子的数量会影响云或雾的反射率，从而影响雾中的能见度或透过云的阳光比例，从而影响地球的能量预算。然而，粒子、云和气候之间的联系仍然没有得到很好的限制。海洋，包括沿海和极地地区，覆盖了地球的70%，但我们对它们排放到大气中的颗粒和颗粒前体（即气体）的理解仍然非常不确定，因为海洋颗粒对气候的最终影响以及通过云和雾形成的能见度。为解决这一问题，拟议的工作将使用各种技术：1）确定海洋表面的化学和物理条件如何在受控实验室环境中影响海洋气溶胶颗粒的特性，并通过建模研究将这些研究结果应用于周围海洋大气; 2）在加拿大北方沿海地区通过扩大人群测试雾的形成和能见度预测-来源的观测网络和详细的观测研究;以及3）通过实地和模拟研究确定粒子的化学和物理特性对雾/云特性（如液滴浓度、能见度和反射率）的影响程度，从而限制海洋地区气溶胶-雾/云的相互作用。总之，这项研究将提高我们对海洋，沿海和极地气溶胶的来源和性质的理解，以及它们通过激活云滴的能力对气候的影响。预计这项工作将通过改进雾的预报，使沿海居民，特别是生活在北部的居民直接受益。这项工作还将通过改进对一次和二次海洋气溶胶的描述，使化学传输建模者受益，并通过提供样本数据集，使气候建模者受益，从而可以将其气溶胶-云相互作用的模拟与之进行比较。