Estimating carbonate parameters from hydrographic data for the intermediate and deep waters of the Southern Hemisphere oceans
Estimating carbonate parameters from hydrographic data for the intermediate and deep waters of the Southern Hemisphere oceans
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根据南半球海洋中层和深水的水文数据估算碳酸盐参数
DOI：
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发表时间：
2013
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通讯作者：
M. Williams
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文献类型：
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作者：
H. Bostock;S. M. Fletcher;M. Williams
利用来自全球数据集的海洋碳数据，我们开发了几种多元线性回归（MLR）算法，仅根据水文数据（温度、盐度和溶解氧）估算南半球（25° S以南）中层和深层沃茨的碱度和溶解无机碳（DIC）。采用Monte Carlo实验确定了不同MLR算法下两种状态之间的最佳断点为27.5的势密度（σ θ）。该算法提供了一个很好的估计DIC（R2 =0.98）和碱度（R2 =0.91），并为文石和方解石的饱和状态（R2 =0.99）优良的协议。结合CSIRO区域海洋地图集（汽车）的算法，我们已经映射的方解石饱和层（CSH）和文石饱和层（ASH）的南大洋在0.5°的空间分辨率。这些地图比以前网格化的全球海洋数据评估方案数据更详细，更符合海洋学。高分辨率的ASH地图揭示了极锋处戏剧性的绕极浅滩。在40° S以北，CSH在大西洋最深（~ 4000 m），在太平洋较浅（~ 2750 m），而CSH位于印度洋3200 - 3400 m之间。随着时间的推移，海洋对人为碳的吸收将改变DIC与中层和深层沃茨水文数据之间的关系。因此，将需要继续采样，并且MLR算法将需要在未来进行调整以考虑这些变化。
Using ocean carbon data from global datasets, we have developed several multiple linear regression (MLR) algorithms to estimate alkalinity and dissolved inorganic carbon (DIC) in the intermediate and deep waters of the Southern Hemisphere (south of 25° S) from only hydrographic data (temperature, salinity and dissolved oxygen). A Monte Carlo experiment was used to identify a potential density (σ θ ) of 27.5 as an optimal break point between the two regimes with different MLR algorithms. The algorithms provide a good estimate of DIC ( R 2 =0.98) and alkalinity ( R 2 =0.91), and excellent agreement for aragonite and calcite saturation states ( R 2 =0.99). Combining the algorithms with the CSIRO Atlas of Regional Seas (CARS), we have mapped the calcite saturation horizon (CSH) and aragonite saturation horizon (ASH) for the Southern Ocean at a spatial resolution of 0.5°. These maps are more detailed and more consistent with the oceanography than the previously gridded GLODAP data. The high-resolution ASH map reveals a dramatic circumpolar shoaling at the polar front. North of 40° S the CSH is deepest in the Atlantic (~ 4000 m) and shallower in the Pacific Ocean (~ 2750 m), while the CSH sits between 3200 and 3400 m in the Indian Ocean. The uptake of anthropogenic carbon by the ocean will alter the relationships between DIC and hydrographic data in the intermediate and deep waters over time. Thus continued sampling will be required, and the MLR algorithms will need to be adjusted in the future to account for these changes.