Water quality parameters from 2000 to 2020 were used to identify the spatial and temporal sulfate variations in estuaries of the northwestern Gulf of Mexico. Sulfate enrichment relative to conservative mixing was found to be associated with a low river discharge period from 2012 to 2014 in all estuaries. Based on reaction stoichiometry, sedimentary sulfide oxidation holds significant potential for reducing the alkalinity in estuarine waters. However, during this extreme drought, alkalinity enrichment was also occasionally observed in some of the southern estuaries along with sulfate enrichment, and when alkalinity depletion occurred, the magnitude of depletion was usually much less than what would be expected based on sulfide oxidation alone. This discrepancy can be partially explained by carbonate dissolution and other proton removal pathways (e.g., Fe-oxide dissolution), and by the uncertainties in the model used to estimate alkalinity enrichment/depletion. Under a changing climate, the close coupling between river discharge variation and estuarine sulfate dynamics will significantly impact estuarine carbonate chemistry.

中文翻译：

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墨西哥湾西北部河口的硫酸盐富集：气候变化下硫化物氧化对碳酸盐化学的潜在影响

利用2000年至2020年的水质参数来确定墨西哥湾西北部河口硫酸盐的时空变化。研究发现，相对于保守混合，硫酸盐富集与 2012 年至 2014 年所有河口的河流流量低期有关。根据反应化学计量，沉积硫化物氧化具有降低河口水域碱度的巨大潜力。然而，在这次极端干旱期间，在南部的一些河口偶尔也会观察到碱度富集和硫酸盐富集，而当发生碱度耗竭时，耗竭的程度通常远小于仅根据硫化物氧化所预期的程度。这种差异可以部分地通过碳酸盐溶解和其他质子去除途径（例如质子去除途径）来解释。例如，铁氧化物溶解），以及用于估计碱度富集/消耗的模型中的不确定性。在气候变化的情况下，河流流量变化与河口硫酸盐动态之间的紧密耦合将显着影响河口碳酸盐化学。