Oxygen Ebullition From Lakes
Oxygen Ebullition From Lakes
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DOI：
10.1002/2017gl074591
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发表时间：
2017-09
影响因子：
5.2
通讯作者：
M. Koschorreck;I. Hentschel;B. Boehrer
中科院分区：
文献类型：
--
作者：
M. Koschorreck;I. Hentschel;B. Boehrer
湖泊和大气之间的氧气交换被认为是由扩散驱动的。在这里，我们展示了湖泊可以通过产生气泡释放出大量的氧气--这一过程被称为沸腾。我们发现，在两个浅层富营养化油藏的浮现气泡中，O2的比例很高，为17±10%(最高为34%)。在所研究的水库中，沸腾释放的O2与扩散的O2通量的大小相似。通过重新分析以前的研究，我们发现这个过程是无处不在的，而且在许多地方可能是定量相关的。我们提出的证据表明，气泡中的氧气既来自光合作用产生的氧气，从而在含氧水中形成气泡，也来自于新出现的甲烷气泡的剥离。沸腾可以将相对于大气不饱和的湖泊转变为净O2源。忽略O2沸腾会导致对湖泊内部呼吸的高估。
The exchange of oxygen between lakes and the atmosphere is assumed to be driven by diffusion. Here we show that lakes can emit significant amounts of O2 by emerging gas bubbles—a process called ebullition. We found very high proportions of 17 ± 10% O2 (maximum 34%) in emerging gas bubbles in two shallow eutrophic reservoirs. In the studied reservoirs, O2 emission by ebullition was of similar magnitude as diffusive O2 fluxes. By reanalyzing previous studies, we show that the process is ubiquitous and probably quantitatively relevant in many places. We present evidence that O2 in bubbles originates both from photosynthetic oxygen production and hence bubble formation in the oxic water and from stripping by emerging methane bubbles. Ebullition can turn lakes undersaturated in respect to the atmosphere into a net O2 source. Neglecting O2 ebullition leads to an overestimation of lake internal respiration.