EAPSI:Investigating Sulfur Sources and Sulfate Oxidation Chemistry in New Zealand Aerosols

硫酸盐气溶胶是气候变化、水循环的重要组成部分，对人类健康有着重大影响，但我们并不完全了解硫的来源，也不完全了解硫是如何在大气中氧化成硫酸盐的。为了研究硫对环境的影响，研究人员与地质与核科学研究所（GNS）合作，将在位于新西兰北岛南端的Baring Head收集气溶胶。与人造硫占主导地位的北方半球相反，南半球的大部分硫来自天然来源和海洋来源。许多Baring Head气溶胶是海洋来源的，这使得研究人员能够在没有陆地影响的情况下评估海洋硫化学。除了独特的采样地点，GNS还拥有评估该项目中硫化学所需的经验、专业知识和分析能力。为了评估硫化学，研究人员将利用硫（d34 S）和氧（d17 O、d18 O、D17 O）的稳定同位素浓度来评估来源和氧化途径。硫同位素允许区分硫的来源（陆地来源的d34 S低;海洋来源的d34 S高），因为d34 S的值在氧化过程中被保留。氧同位素提供洞察氧化途径（气相氧化，D17 O = 0;水相氧化，D17 O 0），形成硫酸盐。此外，通过收集尺寸分离的气溶胶，研究人员将能够分析可比空气质量的气相和水相氧化。较粗的气溶胶比较细的部分更容易发生水相氧化，因为该区域的海水碱性稍强，因此促进了水相氧化。一旦结合起来，预先进行的分析将创建一个强大的数据集，将补充未来的建模项目，并提高对硫酸盐气溶胶对气候变化，水循环和全球人类健康影响的理解。该奖项是与新西兰皇家学会合作资助的。

Sulfate aerosols are a critical part of climate change, the water cycle, and significantly impact human health, yet we do not completely understand the sources of sulfur, nor how it is oxidized into sulfate in the atmosphere. In order to study the impact of sulfur in the environment, researchers in collaboration with the Institute of Geological and Nuclear Science (GNS) will collect aerosols at Baring Head, located on the southern tip of the North Island of New Zealand. In contrast to the Northern Hemisphere, where man-made sulfur dominates, the majority of Southern Hemisphere sulfur is from natural sources and of marine origin. Many Baring Head aerosols are of marine origin, which allows researchers to assess marine sulfur chemistry without terrestrial influences. In addition to the unique sampling location, GNS possesses the experience, expertise, and analytical capability required for evaluating the sulfur chemistry in this project.To assess sulfur chemistry, researchers will utilize the stable isotope concentrations of sulfur (d34S) and oxygen (d17O, d18O, D17O) to evaluate sources and oxidation pathways. Sulfur isotopes allow for the differentiation of sulfur sources (low d34S for land sources; elevated d34S for marine sources), as the value of d34S is retained during oxidation. Oxygen isotopes provide insight to the oxidation pathways (gas phase oxidation, D17O = 0; aqueous phase oxidation, D17O 0) that form sulfate. Additionally, by collecting size segregated aerosols, researchers will be able to analyze gas and aqueous phase oxidation of a comparable air mass. Coarser aerosols are more likely to undergo aqueous phase oxidation than the finer fraction, as sea water in this region is slightly more alkaline thus promoting aqueous oxidation. Once combined, the analyses preformed will create a robust data set that will compliment future modeling projects and enhance the understanding of the impact sulfate aerosols have on climate change, the water cycle, and human health worldwide. This award is funded in collaboration with the Royal Society of New Zealand.