Abstract Eutrophication has been linked to increased greenhouse gas emissions from inland waters. Phytoplankton blooms in Lake Erie have increased since the 1990s, although its greenhouse gas emissions are not well characterized. We measured CH4 and N2O concentrations and diffusive fluxes in four seasons around the entire lake, and CO2 fluxes in one summer season. Lake Erie is a source of CH4 all year across the lake, concentrated in spring and summer in the Western Basin. Methane emissions ranged from 0.03 to 14.87 mg C m−2 d-1. Methane is predominantly biogenic, and natural gas leaks are an insignificant source. While Lake Erie is an overall N2O source, it is an N2O sink in winter and occasionally during summer. Emissions of N2O ranged from −0.08 to 1.22 mg N m−2 d-1. We also measured CO2 fluxes in summer only, when Lake Erie is a small atmospheric CO2 sink. While areal fluxes of CH4 and N2O are similar to those observed elsewhere, total fluxes from Lake Erie are higher due to its surface area. Lake Erie emits ~ 6300 (±19%) metric tons of CH4-C yr−1 and ~600 (±37%) metric tons N2O-N yr−1: almost 500,000 metric tons CO2-eq yr−1 total. This is the first comprehensive dataset of CH4 and N2O concentrations and diffusive emissions in a very large lake. More measurements and monitoring are needed to determine whether increased eutrophication in the Great Lakes is tied to increased emissions of these powerful climate forcers in a possible positive feedback to climate warming.

中文翻译：

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整个伊利湖所有季节测量的甲烷和一氧化二氮表明富营养化西部盆地的排放量最高

摘要 富营养化与内陆水域温室气体排放的增加有关。自 1990 年代以来，伊利湖的浮游植物大量繁殖，尽管其温室气体排放没有得到很好的表征。我们测量了整个湖泊周围四个季节的 CH4 和 N2O 浓度和扩散通量，以及一个夏季的 CO2 通量。伊利湖全年都是整个湖泊的 CH4 来源，集中在西部盆地的春季和夏季。甲烷排放范围为 0.03 至 14.87 mg C m-2 d-1。甲烷主要是生物来源，而天然气泄漏是一个微不足道的来源。虽然伊利湖是 N2O 的整体来源，但它在冬季和夏季偶尔是 N2O 汇。N2O 的排放范围为 -0.08 至 1.22 mg N m-2 d-1。我们还仅在夏季测量了 CO2 通量，当伊利湖是一个小的大气二氧化碳汇时。虽然 CH4 和 N2O 的面积通量与在其他地方观察到的相似，但由于伊利湖的表面积，来自伊利湖的总通量更高。伊利湖排放 ~ 6300 (±19%) 公吨 CH4-C yr−1 和 ~600 (±37%) 公吨 N2O-N yr−1：总计近 500,000 公吨 CO2-eq yr−1。这是第一个关于大型湖泊中 CH4 和 N2O 浓度和扩散排放的综合数据集。需要更多的测量和监测来确定五大湖中富营养化的增加是否与这些强大的气候强迫因素的排放增加有关，这可能是对气候变暖的积极反馈。伊利湖排放 ~ 6300 (±19%) 公吨 CH4-C yr−1 和 ~600 (±37%) 公吨 N2O-N yr−1：总计近 500,000 公吨 CO2-eq yr−1。这是第一个关于大型湖泊中 CH4 和 N2O 浓度和扩散排放的综合数据集。需要更多的测量和监测来确定五大湖中富营养化的增加是否与这些强大的气候强迫因素的排放增加有关，这可能是对气候变暖的积极反馈。伊利湖排放 ~ 6300 (±19%) 公吨 CH4-C yr−1 和 ~600 (±37%) 公吨 N2O-N yr−1：总计近 500,000 公吨 CO2-eq yr−1。这是第一个关于大型湖泊中 CH4 和 N2O 浓度和扩散排放的综合数据集。需要更多的测量和监测来确定五大湖中富营养化的增加是否与这些强大的气候强迫因素的排放增加有关，这可能是对气候变暖的积极反馈。