Understanding Atmospheric Sulfur Cycle using Triple Isotopes of Oxygen and Sulfur (ASCTIOS)

硫酸盐是大气气溶胶的重要化学成分;然而，在地球仪的大部分地区，特别是高纬度地区和南半球，控制其形成的化学成分仍然不受限制。 目前，对人为和自然来源的二氧化硫通量的测量很少，特别是在南半球。硫酸盐气溶胶通过散射和吸收与入射的太阳辐射和出射的陆地辐射发生强烈的相互作用，因此，其粒径分布对了解硫酸盐气溶胶与辐射的相互作用方式具有重要意义。 本研究的主要目的是在澳大利亚格里姆角基线空气污染站的原始海洋环境中开发大气硫酸盐化学的同位素探针，以确定海盐碱度对硫氧化的作用。 氧和硫同位素测量将用于更好地限制控制大气中硫酸盐气溶胶形成和传输的来源和化学性质。 这些结果将被用来解释从南极冰芯获得的古硫酸盐气溶胶数据，并确定人为硫对自然硫循环的贡献，这项研究将有助于阐明硫化学对气候的影响，在一个清洁的海洋背景下，在Cape Grim站，澳大利亚。 这将为评估硫酸盐气溶胶的时间和空间变化建立一个基线，并为今后解释冰芯数据提供基础。 鉴于与用于再现硫酸盐水平的全球化学模型相关的固有问题，这种新的分析工具有可能改进全球化学模型，从而可以更好地诊断人为硫酸盐来源造成的潜在变化。 该项目还有一个更广泛的目标，即通过培训一名博士后科学家以及研究生和本科生，进一步发展该领域的人力资源。

Sulfate is a significant chemical component of atmospheric aerosols; however, the chemistry governing its formation over a large portion of the globe, particularly the high latitudes and southern hemisphere remains unconstrained. At present there are sparse measurements of sulfur dioxide fluxes from anthropogenic and natural sources, particularly in the southern hemisphere. Sulfate aerosols interact strongly with incoming solar and outgoing terrestrial radiations by scattering and absorption, therefore size distribution is of high significance to understand the mode of interaction of sulfate aerosols with radiation. The primary objective of this study is to develop an isotopic probe of atmospheric sulfate chemistry in a pristine marine environment at Cape Grim Baseline Air Pollution Station, Australia to identify the role of sea salt alkalinity on the oxidation of sulfur. Oxygen and sulfur isotope measurements will be used to better constrain the sources and chemistry controlling the formation and transport of sulfate aerosol in the atmosphere. These results will be used to interpret paleo-sulfate aerosol data obtained from Antarctic ice cores and to identify the contribution of anthropogenic sulfur to the natural sulfur cycle.This research will help to elucidate the impact of sulfur chemistry on climate in a clean oceanic background at Cape Grim Station, Australia. This will establish a baseline for evaluating temporal and spatial variations in sulfate aerosols and will provide a basis for the future interpretation of ice core data. In view of the inherent problems associated with global chemistry models used to reproduce the sulfate levels, this new analytical tool has the potential to improve global chemistry models and in turn this may enable a better diagnosis of potential changes that result from anthropogenic sulfate sources. This project also has the broader goal of furthering the development of human resources in the field by training a postdoctoral scientist and graduate and undergraduate students.