The marine carbonate system is influenced by anthropogenic CO2 uptake, biogeochemical processes, and physical changes that involve freshwater input and removal. Two frequently used parameters to quantify seawater carbonate system are total alkalinity (TA) and total dissolved inorganic carbon (DIC). To account for the physical changes, both TA and DIC are usually normalized to a reference salinity (i.e., nTA and nDIC), and then the relationship between nTA and nDIC is used to identify major biogeochemical processes that regulate the carbonate system, based on process‐specific reaction stoichiometry. However, the theoretical basis of this interpretation has not been holistically examined. In this study, we validated this method under idealized conditions and discussed the associated assumptions and limitations. Furthermore, we applied this method to interpret field TA and DIC data from a lagoonal estuary in the northwestern Gulf of Mexico. Our results demonstrated that evaluating field data that encompass multiple stations and time periods could be problematic. In addition, various combinations of biogeochemical processes can lead to the same nTA–nDIC relationship, even though the relative importance of each individual process may vary significantly. Therefore, the stoichiometric relationship relying solely on TA and DIC data is not a definitive approach for uncovering dominant biogeochemical processes. Instead, measurements of process‐specific parameters are necessary.

中文翻译：

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通过总碱度与溶解无机碳之间的关系解释生物地球化学过程：理论基础和局限性

海洋碳酸盐系统受人为二氧化碳的影响2涉及淡水输入和去除的吸收、生物地球化学过程和物理变化。量化海水碳酸盐系统的两个常用参数是总碱度（TA）和总溶解无机碳（DIC）。为了解释物理变化，通常将 TA 和 DIC 标准化为参考盐度（即 nTA 和 nDIC），然后根据过程，使用 nTA 和 nDIC 之间的关系来识别调节碳酸盐系统的主要生物地球化学过程。 ‐特定反应化学计量。然而，这种解释的理论基础尚未得到全面检验。在本研究中，我们在理想条件下验证了该方法，并讨论了相关的假设和局限性。此外，我们应用该方法解释了墨西哥湾西北部泻湖河口的现场 TA 和 DIC 数据。我们的结果表明，评估包含多个站点和时间段的现场数据可能会出现问题。此外，生物地球化学过程的各种组合可以导致相同的 nTA-nDIC 关系，即使每个单独过程的相对重要性可能有很大差异。因此，仅依赖 TA 和 DIC 数据的化学计量关系并不是揭示主要生物地球化学过程的明确方法。相反，需要测量特定于过程的参数。