Lake heatwaves under climate change
Lake heatwaves under climate change
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DOI：
10.1038/s41586-020-03119-1
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发表时间：
2021-01-21
期刊：
影响因子：
64.8
通讯作者：
Maberly, Stephen C.
中科院分区：
文献类型：
--
作者：
Woolway, R. Iestyn;Jennings, Eleanor;Maberly, Stephen C.
湖泊生态系统和生活在其中的生物体容易受到温度变化的影响(1-5)，包括极端温度的增加(6)。然而，人们对湖泊热浪-极端温暖的湖面水温时期-以及它们在全球变暖下可能发生的变化知之甚少。在这里，我们使用卫星观测和一个数值模型来研究从1901年到2099年全球数百个湖泊热波的变化。我们预测，到21世纪末，湖泊热浪将变得更热、更长。在温室气体排放量高的情况下(典型浓度路径8.5)，湖泊热浪的平均强度(相对于历史时期(1970至1999年))将从3.7+/-0.1摄氏度增加到5.4+/-0.8摄氏度，其平均持续时间将从7.7+/-0.4天急剧增加到95.5+/-35.3天。在低温室气体排放的RCP 2.6情景中，热浪强度和持续时间将分别增加到4.0+/-0.2摄氏度和27.0+/-7.6天。在历史和未来时期，表层热浪在较深的湖泊(深达60米)中持续时间更长，但强度低于较浅湖泊。随着湖泊在21世纪(7，8)变暖，它们的热浪将开始跨越多个季节，一些湖泊将达到永久热浪状态。湖泊热浪可能会加剧湖泊长期变暖的不利影响，并对湖泊的物理结构和化学性质产生广泛影响。湖泊热浪可能会将水生物种和生态系统推向其弹性极限，从而改变物种组成。这反过来可能威胁到湖泊的生物多样性(9)以及湖泊为社会提供的主要生态和经济利益。
Lake ecosystems, and the organisms that live within them, are vulnerable to temperature change(1-5), including the increased occurrence of thermal extremes(6). However, very little is known about lake heatwaves-periods of extreme warm lake surface water temperature-and how they may change under global warming. Here we use satellite observations and a numerical model to investigate changes in lake heatwaves for hundreds of lakes worldwide from 1901 to 2099. We show that lake heatwaves will become hotter and longer by the end of the twenty-first century. For the high-greenhouse-gas-emission scenario (Representative Concentration Pathway (RCP) 8.5), the average intensity of lake heatwaves, defined relative to the historical period (1970 to 1999), will increase from 3.7 +/- 0.1 to 5.4 +/- 0.8 degrees Celsius and their average duration will increase dramatically from 7.7 +/- 0.4 to 95.5 +/- 35.3 days. In the low-greenhouse-gas-emission RCP 2.6 scenario, heatwave intensity and duration will increase to 4.0 +/- 0.2 degrees Celsius and 27.0 +/- 7.6 days, respectively. Surface heatwaves are longer-lasting but less intense in deeper lakes (up to 60 metres deep) than in shallower lakes during both historic and future periods. As lakes warm during the twenty-first century(7,8), their heatwaves will begin to extend across multiple seasons, with some lakes reaching a permanent heatwave state. Lake heatwaves are likely to exacerbate the adverse effects of long-term warming in lakes and exert widespread influence on their physical structure and chemical properties. Lake heatwaves could alter species composition by pushing aquatic species and ecosystems to the limits of their resilience. This in turn could threaten lake biodiversity(9) and the key ecological and economic benefits that lakes provide to society.