Sources, Visibility and Climate Effects of Marine Aerosols

液云和雾滴，就像沸水中的水蒸气一样，在大气中预先存在的气溶胶颗粒上形成，颗粒的大小和化学成分影响它们形成液滴的能力。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层的太阳光的比例，从而影响地球的能量收支。然而，颗粒、云层和气候之间的联系仍然受到很少的限制。海洋，包括沿海和极地地区，覆盖了地球的70%，但我们对海洋排放到大气中的粒子和粒子前体(即气体)的理解仍然高度不确定，海洋粒子通过云和雾的形成对气候和能见度的最终影响也是高度不确定的。为解决这一问题，拟议的工作将利用各种技术来1)确定在受控制的实验室环境下表层海洋化学和物理条件如何影响海洋气溶胶粒子的性质，并通过模拟研究将这些研究结果应用于周围海洋大气；2)通过扩大众包观测网络和进行详细的观测研究，测试加拿大北部沿海地区的雾形成和能见度预测；3)通过实地研究和模拟研究，确定粒子的化学和物理性质在多大程度上影响雾/云的属性，如水滴的浓度、能见度和反射率，从而约束海洋各地点的气溶胶-雾/云相互作用。综上所述，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以及它们作为云滴激活的能力对气候的影响的理解。预计这项工作将通过改进雾预报，直接惠及沿海居民，特别是生活在北部的居民。这项工作还将通过改进初级和次级海洋气溶胶的特征，使化学输送模型建模者受益，并通过提供样本数据集，使气候模型建模者受益，以便与它们对气溶胶-云相互作用的模拟进行比较。

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.