Abstract Using the most comprehensive, high quality, high-resolution dataset for any marginal sea up to depths >2000 db, we examined the seasonality of the carbonate system in the northern South China Sea (nSCS) and exchange with the West Philippine Sea (WPS) during 2009-2011. The carbonate system dynamics demonstrated evident spatial and seasonal variations. Winter exhibited the highest average surface dissolved inorganic carbon (DIC) concentrations (1936 ± 15 μmol kg-1), and summer had the lowest (1882 ± 12 μmol kg-1), primarily associated with more abundant freshwater inputs in summer. At 100 db depth, decreased DIC and total alkalinity (TA) values were observed within the vicinity of the Luzon Strait due to the influence of WPS waters. Higher DIC and TA concentrations were found within the central nSCS basin. The average Kuroshio contribution to the DIC inventory in the upper 150 db was seasonally significant, ranging between 11-32%, with the highest contributions during spring and winter. Below 2000 db, nSCS basin-averaged DIC was significantly higher than WPS-averaged DIC (∼23 µmol kg-1 difference) due to more organic matter decomposition in the nSCS basin. Within the basin, average deep water DIC values were highest in autumn, and averaged concentrations at >18.5°N were lower than at ≤18.5°N. Our datasets and analysis imply that (i) the significant seasonal and spatial patterns of carbonate chemistry in the nSCS are controlled by a combination of large-scale and smaller mesoscale physical processes; (ii) extrinsically from Asian monsoons via seasonal freshwater discharge and dynamic exchanges with open ocean waters; and (iii) intrinsically, through seasonal vertical mixing as well as mesoscale processes and their subsequent new productions. The seasonal and spatial variability in carbonate parameters established here serves as an essential baseline to monitor future changes to the nSCS and to compare with other marginal sea systems. AGU index terms: 0414 Biogeochemical cycles, processes, and modeling, 1635 Oceans, 4243 Marginal and semi-enclosed seas, 4277 Time series experiments, 4283 Water masses, 4806 Carbon cycling, 4835 Marine inorganic chemistry,

中文翻译：

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南海北部碳酸盐岩系统：季节性及与西北太平洋的交换

摘要 使用深度 > 2000 db 的任何边缘海的最全面、高质量、高分辨率的数据集，我们检查了南海北部 (nSCS) 和与西菲律宾海 (WPS) 交换碳酸盐系统的季节性) 2009-2011 年期间。碳酸盐系统动力学表现出明显的空间和季节变化。冬季表现出最高的平均表面溶解无机碳 (DIC) 浓度 (1936 ± 15 μmol kg-1)，夏季最低 (1882 ± 12 μmol kg-1)，主要与夏季更丰富的淡水输入有关。在 100 db 深度处，由于 WPS 水域的影响，在吕宋海峡附近观察到 DIC 和总碱度 (TA) 值降低。在中央 nSCS 盆地内发现了更高的 DIC 和 TA 浓度。黑潮对 150 db 以上 DIC 库存的平均贡献具有季节性显着性，范围在 11-32% 之间，春季和冬季的贡献最高。低于 2000 db，nSCS 盆地平均 DIC 显着高于 WPS 平均 DIC（~23 µmol kg-1 差异），因为 nSCS 盆地中有更多的有机物分解。在流域内，秋季平均深水 DIC 值最高，>18.5°N 的平均浓度低于≤18.5°N 的浓度。我们的数据集和分析表明 (i) nSCS 中碳酸盐化学的显着季节性和空间模式受大尺度和小尺度物理过程的组合控制；(ii) 通过季节性淡水排放和与公海水域的动态交换，来自亚洲季风；(iii) 本质上，通过季节性垂直混合以及中尺度过程及其随后的新产品。此处建立的碳酸盐参数的季节性和空间变异性是监测 nSCS 未来变化并与其他边缘海洋系统进行比较的重要基线。AGU 指数术语：0414 生物地球化学循环、过程和建模，1635 大洋，4243 边缘和半封闭海，4277 时间序列实验，4283 水团，4806 碳循环，4835 海洋无机化学，