Oxidation of thin film at the air-water interface of cloud droplets using REAL atmospheric aerosol from polar, marine and urban sources

The Earth's climate is strongly influenced by clouds. The oxidative processing of pollutants in clouds affects droplet size and optical properties, important effects. Common cloud pollutants are naturally occurring organic surfactants forming organic films on the droplet, The climatic effect depends on the rate of atmospheric oxidation of these films and whether any product film forms. In this work we will study the kinetics of hydroxyl radical with insoluble surfactants from samples from Antarctica, mid-Atlantic and Urban London. Specifically we will (a) demonstrate that an aqueous cloud oxidant, the OH radical, can oxidise a real atmospheric organic film with different provenances, b) calculate the effect of the reaction on the hygroscopic properties of a cloud droplet and demonstrate removal of the organic film may cause a cloud to evaporate (c) Support an STFC futures grant.云对地球气候具有显著影响。云内污染物的氧化过程会改变云滴粒径与光学特性，此类变化具备重要的气候效应。常见的云污染物为天然有机表面活性剂，它们可在云滴表面形成有机膜。气候效应取决于这些有机膜的大气氧化速率，以及是否会生成反应产物膜。 本研究将针对取自南极、大西洋中部以及伦敦市区的不溶性表面活性剂样品，开展羟基自由基（hydroxyl radical）与该类物质的反应动力学研究。具体研究内容如下： （a）证实作为水相云氧化剂的羟基自由基可氧化不同来源的真实大气有机膜； （b）量化该反应对云滴吸湿性的影响，并证实有机膜的脱除可能引发云体蒸发； （c）为科学与技术设施委员会（Science and Technology Facilities Council, STFC）的未来资助项目提供研究支撑。