当前位置: X-MOL 学术Glob. Biogeochem. Cycles › 论文详情
Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)
Why are Surface Ocean pH and CaCO3 Saturation State Often out of Phase in Spatial Patterns and Seasonal Cycles?
Global Biogeochemical Cycles ( IF 5.2 ) Pub Date : 2021-06-16 , DOI: 10.1029/2021gb006949
Liang Xue 1, 2, 3 , Wei‐Jun Cai 4 , Li‐Qing Jiang 5, 6 , Qinsheng Wei 1
Affiliation  

As two most important metrics for ocean acidification (OA), both pH and calcium carbonate mineral saturation states (Ω) respond sensitively to anthropogenic carbon dioxide (CO2). However, contrary to intuition, they are often out of phase in the global surface ocean, both spatially and seasonally. For example, during warm seasons, Ω is lowest at high-latitude seas where there are very high pH values, challenging our understanding that high-latitude seas are a bellwether for global OA. To explain this phenomenon, we separate spatial and seasonal variations of both pH and Ω into thermal components mainly associated with internal acid-base equilibrium of seawater CO2 systems, and nonthermal components mainly associated with external CO2 addition/removal using a global surface ocean climatological data set. We find that surface pH change is controlled by the balance between its thermal and nonthermal components, which are out of phase but comparable in magnitude. In contrast, surface Ω change is dominated by its nonthermal components, with its thermal components in phase and significantly smaller in magnitude. These findings explain why surface ocean pH and Ω are often out of phase in spatial patterns and seasonal cycles. When pH is primarily controlled by nonthermal components e.g., gas exchange, mixing and biology, pH and Ω will be in phase because their nonthermal components are intrinsically in phase. In comparison, when pH is primarily controlled by thermal components for example, rapid seasonal cooling or warming, pH and Ω will be out of phase because thermal and nonthermal components of pH are out-of-phase in nature.

中文翻译:

为什么表面海洋 pH 值和 CaCO3 饱和状态在空间模式和季节周期中经常异相?

作为海洋酸化 (OA) 的两个最重要的指标,pH 值和碳酸钙矿物饱和状态 (Ω) 对人为二氧化碳 (CO 2 )反应灵敏。然而,与直觉相反,它们在全球表层海洋中通常在空间和季节上都是异相的。例如,在温暖的季节,Ω 在 pH 值非常高的高纬度海域最低,这对我们认为高纬度海域是全球 OA 风向标的理解提出了挑战。为了解释这一现象,我们将 pH 和 Ω 的空间和季节变化分为主要与海水 CO 2系统内部酸碱平衡相关的热成分和主要与外部 CO 2相关的非热成分使用全球表面海洋气候数据集添加/删除。我们发现表面 pH 值变化是由其热和非热成分之间的平衡控制的,这些成分异相但大小相当。相比之下,表面 Ω 变化由其非热分量主导,其热分量同相且幅度明显较小。这些发现解释了为什么表面海洋 pH 值和 Ω 在空间模式和季节周期中经常异相。当 pH 主要由非热成分(例如气体交换、混合和生物)控制时,pH 和 Ω 将同相,因为它们的非热成分本质上是同相的。相比之下,当 pH 值主要由热成分控制时,例如快速的季节性降温或升温,
更新日期:2021-07-04
down
wechat
bug