Constraining the role of the marine sulfur cycle in the Earth System (CARES)

限制海洋硫循环在地球系统中的作用（CARES）

• 批准号: NE/W009412/1
• 负责人: Alexander Archibald
• 金额: $ 60.22万
• 依托单位: University of Cambridge
• 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%2FW009412%2F1
• 关键词: Constraining; role; marine; sulfur; cycle

The marine sulfur cycle is an exemplar of a climatically important biogeochemical cycle within the Earth system (initially described by the CLAW hypothesis). Marine sulfate aerosol produced from biogenic dimethyl sulfide (DMS) is the main component of natural aerosol over many oceanic regions and sets a baseline aerosol concentration against which the magnitude of anthropogenic aerosol radiative forcing is determined. However, recent discoveries of new sulfur molecules formed from DMS (e.g., HPMTF) force us to radically re-examine the role of marine sulfur in the climate system. The understanding embedded in current climate models is now significantly challenged by new aerosol formation pathways and by observations of marine emissions of other biogenic sulfur species that were previously dismissed as unimportant: What do these molecules do? How do the processes they participate in affect the natural sulfur cycle? How do these discoveries alter the impact of DMS emissions on climate and anthropogenically driven climate change? The recently discovered species and chemical pathways are not included in any Earth system models that inform global climate change policies through the IPCC, even though aerosols from natural sources are a key driver of uncertainty in radiative forcing. The significant gap in understanding of the natural sulfur cycle is a major limitation when trying to constrain the pre-industrial climate system, which is itself crucial for determining the allowed emissions of greenhouse gases needed to meet climate stabilisation targets.The CARES project will fill these holes in our knowledge of the marine atmospheric sulfur cycle through a combination of intensive aircraft and ship observations as well as multi-scale model experiments. Advancements in models, further informed by new laboratory data, will allow us to better understand contemporary and historical sulfur and climate observations. This will deliver a substantial revision to our understanding of the fate and impact of natural sulfur emissions. The results will be used to rectify errors in the representation of sulfur processes in Earth system models, constrain the role of marine sulfur in the Earth System, and improve confidence in simulations that project future change.

海洋硫循环是地球系统内气候上重要的生物地球化学循环的一个例子（最初由爪假说描述）。由生物二甲基硫化物（DMS）产生的海洋硫酸盐气溶胶是许多海洋地区天然气溶胶的主要成分，并设定了基线气溶胶浓度，该浓度确定了人为气溶胶辐射强迫的幅度。然而，最近发现由DMS（例如HPMTF）形成的新硫分子的发现迫使我们从根本上重新检查了海洋硫在气候系统中的作用。现在，嵌入在当前气候模型中的理解受到新的气溶胶形成途径的挑战，以及对以前不重要的其他生物硫物种的海洋排放的观察：这些分子有什么？它们参与的过程如何影响自然硫周期？这些发现如何改变DMS排放对气候和人为驱动的气候变化的影响？最近发现的物种和化学途径都不包含在通过IPCC为全球气候变化政策提供信息的任何地球系统模型中，即使来自天然来源的气溶胶是辐射强迫不确定性的关键驱动力。在试图限制工业前气候系统时，了解自然硫周期的显着差距是一个主要局限性，这本身对于确定满足气候稳定目标所需的温室气体所需的允许的温室气体至关重要。CARES项目将在我们对海洋大气硫酸周期中的知识中填补这些孔，并通过建模量和乘船进行实验。新实验室数据进一步告知模型的进步将使我们能够更好地了解当代和历史硫和气候观察。这将对我们对自然硫排放的命运和影响的理解进行大量修改。结果将用于纠正地球系统模型中硫过程表示的错误，限制海洋硫在地球系统中的作用，并提高对预测未来变化的模拟的信心。