Physical and chemical impacts of a major storm on a temperate lake: a taste of things to come?
Physical and chemical impacts of a major storm on a temperate lake: a taste of things to come?
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DOI：
10.1007/s10584-018-2302-3
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发表时间：
2018-10
期刊：
影响因子：
4.8
通讯作者：
R. Woolway;John H. Simpson;David Spiby;H. Feuchtmayr;B. Powell;S. Maberly
中科院分区：
文献类型：
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作者：
R. Woolway;John H. Simpson;David Spiby;H. Feuchtmayr;B. Powell;S. Maberly
极端天气可能会对湖泊产生重大影响，预计随着气候变化，极端天气将变得更加频繁。我们探索了一个特殊的极端事件，风暴奥菲莉亚，对英格兰最大的湖泊温德米尔湖的物理和化学环境的影响。我们发现，欧菲莉亚对温德米尔的气象条件，特别是风速有很大的影响，导致湖-空气界面的风能通量增加了25倍(相对于研究期间的平均值)。在欧菲利亚之后，发生了一次短暂的混合事件，其中施密特稳定度在12小时内下降了100%以上JM−2，温跃层加深了10%以上。由于层结强度的变化，欧菲莉亚也改变了温德米尔的内部海冰体制，主要海流周期从风暴前的~ 17小时增加到风暴后的~ 21小时。在欧菲莉亚之后，在湖的南端有一股寒冷和低含氧量的海水涌出。这对温德米尔的主要流出河流利文河产生了实质性的影响，那里的溶解氧浓度下降了~ 48%，从L−1的9.3%下降到4.8亿mg，而在温德米尔的湖中监测站，下降了~ 3%。这项研究表明，湖泊对极端天气的反应可以在下游造成重要影响，这种影响在湖面可能不明显。为了充分了解未来极端事件的影响，需要对整个湖泊和下游河流系统进行共同研究。
Extreme weather can have a substantial influence on lakes and is expected to become more frequent with climate change. We explored the influence of one particular extreme event, Storm Ophelia, on the physical and chemical environment of England’s largest lake, Windermere. We found that the substantial influence of Ophelia on meteorological conditions at Windermere, in particular wind speed, resulted in a 25-fold increase (relative to the study-period average) in the wind energy flux at the lake-air interface. Following Ophelia, there was a short-lived mixing event in which the Schmidt stability decreased by over 100 Jm−2and the thermocline deepened by over 10 m during a 12-h period. As a result of changes to the strength of stratification, Ophelia also changed the internal seiche regime of Windermere with the dominant seiche period increasing from ~ 17 h pre-storm to ~ 21 h post-storm. Following Ophelia, there was an upwelling of cold and low-oxygenated waters at the southern-end of the lake. This had a substantial influence on the main outflow of Windermere, the River Leven, where dissolved oxygen concentrations decreased by ~ 48%, from 9.3 to 4.8 mg L−1, while at the mid-lake monitoring station in Windermere, it decreased by only ~ 3%. This study illustrates that the response of a lake to extreme weather can cause important effects downstream, the influence of which may not be evident at the lake surface. To understand the impact of future extreme events fully, the whole lake and downstream-river system need to be studied together.