The role of mesoscale eddies in Southern Ocean Carbon fluxes from autonomous ocean gliders

中尺度涡流在南大洋自主海洋滑翔机碳通量中的作用

• 批准号: 2371105
• 金额: --
• 依托单位: University of Southampton
• 依托单位国家: 英国
• 项目类别: Studentship
• 财政年份: 2018
• 资助国家: 英国
• 起止时间: 2018 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=studentship-2371105
• 关键词: role; mesoscale; eddies; Southern; Ocean

The Southern Ocean (SO) is thought to account for the uptake of ~40% of all global human-derived (anthropogenic) carbon dioxide and >75% of anthropogenic heat, thus being disproportionately influential in the ongoing mitigation of increasing atmospheric CO2 levels and related climate effects. SO CO2 fluxes are a delicate balance of multiple processes; temperature-driven solubility effects, biological carbon drawdown driven by vertical nutrient supply, upwelling-derived outgassing of remineralised carbon, sea-ice formation and melt, and circulation features such as large-scale overturning or mesoscale eddies together combine to make flux estimates difficult and highly uncertain. Our understanding of their present state and future behaviour are limited by both spatial and temporal sparsity of observations, and the inability of models to replicate them, particularly circulation-driven biological effects. Recently, biogeochemical floats (sampling the water column's top 2000m every 10 days) have massively increased data coverage and led to new flux estimates suggesting a much smaller regional CO2 sink than previously thought. However, float sampling strategies are thought to be insufficient to capture the intensity of short-lived major flux events and features (such as eddies), and the variability of their occurrence, which may compromise their estimates. High frequency glider observations offer the opportunity to fill these gaps, thereby reconciling disparities between integrated observational budget estimates and biogeochemical models, and reducing uncertainties in flux estimates.

南大洋（SO）被认为吸收了全球所有人为（人为）二氧化碳的约40%和>75%的人为热量，因此在持续缓解大气CO2水平和相关气候效应方面具有不成比例的影响力。SO-CO2通量是多个过程的微妙平衡;温度驱动的溶解度效应、垂直养分供应驱动的生物碳下降、上涌衍生的矿化碳释气、海冰形成和融化以及大尺度翻转或中尺度涡旋等环流特征一起联合收割机使通量估计变得困难且高度不确定。我们对它们目前状态和未来行为的理解受到空间和时间观测稀疏性的限制，以及模型无法复制它们，特别是循环驱动的生物效应。最近，地球化学浮标（每10天对水柱顶部2000米进行一次采样）大大增加了数据覆盖范围，并导致了新的通量估计，表明区域CO2汇比以前认为的要小得多。然而，浮动采样策略被认为不足以捕捉短寿命的主要通量事件和特征（如涡旋）的强度及其发生的可变性，这可能会影响其估计。高频滑翔机观测提供了填补这些空白的机会，从而调和综合观测预算估计和地球化学模型之间的差异，并减少通量估计的不确定性。