从海洋颜色看气候的变化
论文标题：Spontaneous droplets gyrating via asymmetric self-splitting on heterogeneous surfaces
作者：Stephanie Dutkiewicz, Anna E. Hickman, Oliver Jahn, Stephanie Henson, Claudie Beaulieu, Erwan Monier
发表时间：2019/02/04
论文标签：Climate change, Marine biology
数字识别码： 10.1038/s41467-019-08457-x
原文链接：http://t.cn/EIaFswY
叶绿素a的变化是监测海洋浮游植物的全球变化的间接指标。在本研究中，作者发现，在21世纪，遥感反射率（海洋表面处的上行光和下行光的比值）会更早更强烈地传递出气候变化导致的信号。
海洋浮游植物是海洋食物链的基础，在碳循环中至关重要，因此，监测它们的变化是一项非常重要的工作。因为有全球卫星的定期估算数据，通常，人们使用叶绿素a来追踪浮游植物的变化。然而，叶绿素a并不能通过卫星感应器直接测得，而是要通过遥感反射率（remote sensing reflectance，RRS，即海洋表面处的上行辐亮度和下行辐照度的比值）来进行估算。
近期，在发表于Nature Communications的一篇文章Ocean colour signature of climate change中，来自麻省理工学院的Stephanie Dutkiewicz及同事通过一个模型发现，比起叶绿素a，蓝绿光谱段中的RRS或许可以更早更强烈地传递出气候变化导致的信号。这是因为RRS的自然变异更低，而且它不仅仅集合了水中叶绿素a的变化，也包括了其他重要的光学组分的变化。浮游植物群落的结构能强烈地影响海洋的光学特征，所以从反映海洋生态基础变化的角度来说，它传递出的信号或许是最明显、最迅速的之一。
摘要：Monitoring changes in marine phytoplankton is important as they form the foundation of the marine food web and are crucial in the carbon cycle. Often Chlorophyll-a (Chl-a) is used to track changes in phytoplankton, since there are global, regular satellite-derived estimates. However, satellite sensors do not measure Chl-a directly. Instead, Chl-a is estimated from remote sensing reflectance (RRS): the ratio of upwelling radiance to the downwelling irradiance at the ocean’s surface. Using a model, we show that RRS in the blue-green spectrum is likely to have a stronger and earlier climate-change-driven signal than Chl-a. This is because RRS has lower natural variability and integrates not only changes to in-water Chl-a, but also alterations in other optically important constituents. Phytoplankton community structure, which strongly affects ocean optics, is likely to show one of the clearest and most rapid signatures of changes to the base of the marine ecosystem.
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期刊介绍：Nature Communications (https://www.nature.com/ncomms/) is an open access journal that publishes high-quality research from all areas of the natural sciences. Papers published by the journal represent important advances of significance to specialists within each field.
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（来源：科学网）
