NSFGEO-NERC: Impacts of sea ice melt and anthropogenic emmisions on biogenic sulfur aerosol as measured in a central Greenland ice core

NSFGEO-NERC：在格陵兰中部冰芯中测量的海冰融化和人为排放对生物硫气溶胶的影响

• 批准号: NE/Y001710/1
• 负责人: Andrea Burke
• 金额: $ 29.68万
• 依托单位: University of St Andrews
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2023
• 资助国家: 英国
• 起止时间: 2023 至 无数据
• 项目状态: 未结题
• 来源: https://gtr.ukri.org/projects?ref=NE%2FY001710%2F1
• 关键词: NSFGEO; NERC; Impacts; sea; ice

Ice-core observations of methane sulfonic acid (MSA) are used as a proxy for past oceanic biogenic productivity because MSA originates solely from the oxidation of dimethyl sulfide (DMS) emitted by ocean phytoplankton. The use of MSA as a proxy for biogenic productivity relies on the assumption that the branching ratio of production of MSA versus sulfur dioxide (SO2) from DMS oxidation remains constant over time. However, recent Greenland ice-core observations of MSA and biogenic sulfate over the last 800 years show that the ratio of MSA-to-biogenic sulfate (MSA/bioSO4) has not remained constant.We hypothesize that recent trends in MSA are driven by changes in oxidant abundances (e.g., NOx) that lead to a reduced yield of MSA and increased yield of SO2 during oxidation of DMS.We propose to drill shallow ice cores at Summit, Greenland covering the last 30 years of snow accumulation and measure ion and MSA concentrations and sulfur isotopes of sulfate. The last 30 years will cover the time when anthropogenic NOx emissions from North America and Europe began to decline (after the mid-1990s). This will yield an additional 16 years of data compared to our current record extending from 1200 C.E. through 2006.We hypothesize that the MSA/bioSO4 ratio continues to increase from the mid-1990s to the present day due to decreases in NOx emissions in North America and Europe.To assist data interpretation, we will utilize a global chemical transport model GEOS-Chem in order to quantify the role of different oxidants on DMS oxidation as these oxidants have changed due to anthropogenic emissions. We will measure sulfate isotopes at sub-seasonal resolution over the last 30 years of snow accumulation from the proposed shallow ice cores in addition to select, discrete samples from archived ice in the preindustrial.We hypothesize that DMS emissions peak earlier in in the year today than in the preindustrial due to the earlier sea-ice melt resulting from Arctic warming.Measuring biogenic sulfate at seasonal resolution since the preindustrial will allow us to investigate changes in the seasonality of biogenic sulfur aerosol in the Arctic resulting from changes in Arctic climate. This is a collaborative project between PIs in the US and the UK, and the UK part of the project will be supported by NERC.

甲烷磺酸（MSA）的冰核观察结果被用作过去海洋生物生产力的代理，因为MSA仅起源于海洋浮游植物发出的二甲基硫化物（DMS）的氧化。使用MSA作为生物生产力的代理取决于以下假设：从DMS氧化中，MSA的生产比MSA的分支比MSA的生产比（SO2）随着时间的流逝而保持恒定。但是，最近800年中，格陵兰对MSA和生物硫酸盐的最近观察结果表明，MSA与生物生物源性硫酸盐的比率（MSA/Bioso4）并不保持恒定。我们假设MSA的最新趋势是MSA的最新趋势是由氧化量和氧化量的变化而导致氧化量的变化而驱动的（例如，SOA的提高效率）的造成的效率，则氧化量会降低。在山顶上钻浅冰芯，覆盖了雪的最后30年的降雪，并测量离子和MSA浓度以及硫酸盐的硫同位素。过去30年将涵盖北美和欧洲的人为NOX排放开始下降的时期（1990年代中期之后）。与我们目前从1200年至2006年延长的记录相比，这将产生另外16年的数据。我们假设MSA/Bioso4比率从1990年代中期到当天持续增加，从北美和欧洲的NOX排放降低，由于数据解释，我们将在全球化学化学模型中使用这些作用，以在北美的NOX排放量下降，以便使用这些氧气的氧气，以便在这些氧气中使用这些作用，从而在这些氧气中使用这些作用，从而在这些序列中使用这些作用，以量身定量的作用，以使这些作用差异为差异。氧化剂由于人为排放而发生了变化。我们还将在过去30年中以亚地区分辨率测量硫酸盐同位素，除了选择，除了选择，在生产前生产的冰芯中选择的，从档案前的冰上进行离散的样品外，我们假设DMS的排放量在一年中早在一年中早于较早的固定型在较早的固定型中，而不是在较早的固定速度的固定型中，以固定的速度延伸。将使我们能够研究北极气候变化导致北极中生物硫气溶胶季节性的变化。这是美国和英国PI之间的合作项目，该项目的英国将得到NERC的支持。