Wide-spread inconsistency in estimation of lake mixed depth impacts interpretation of limnological processes
Wide-spread inconsistency in estimation of lake mixed depth impacts interpretation of limnological processes
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DOI：
10.1016/j.watres.2019.115136
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发表时间：
2020-01-01
期刊：
影响因子：
12.8
通讯作者：
Jones, Ian D.
中科院分区：
文献类型：
--
作者：
Gray, Emma;Mackay, Eleanor B.;Jones, Ian D.
混合层或表层是一个物理概念，指的是水体表面的等温层。这一概念在湖泊学中无处不在，是我们理解化学和生态过程的基础，也是水体监测、评估和管理的重要指标。尽管它作为一种度量标准很重要，但目前存在许多不同的方法来近似混合深度。利用2016年和2017年在英国一个小型中富营养化湖泊的实地活动数据，我们测试了混合深度的不同定义是否导致可比的估计，以及是否可以假设温度以外的变量在层内混合。不同的方法导致了对混合深度的非常不同的估计，生态上重要的变量不一定均匀地分布在表层。此外，基于混合深度的简单生态相关指标的计算表明，这些指标高度依赖于所使用的混合深度的定义。结果表明，定义明确的完全混合层的理想化概念不一定是合适的。对混合深度的多种定义的广泛使用削弱了不同研究的可比性，而对最适当定义的相关不确定性限制了利用混合深度进行研究的确认性。(C)2019爱思唯尔有限公司。保留所有权利。
The mixed layer, or epilimnion, is a physical concept referring to an isothermal layer at the surface of a water body. This concept is ubiquitous within limnology, is fundamental to our understanding of chemical and ecological processes, and is an important metric for water body monitoring, assessment and management. Despite its importance as a metric, many different approaches to approximating mixed depth currently exist. Using data from field campaigns in a small meso-eutrophic lake in the UK in 2016 and 2017 we tested whether different definitions of mixed depth resulted in comparable estimates and whether variables other than temperature could be assumed to be mixed within the layer. Different methods resulted in very different estimates for the mixed depth and ecologically important variables were not necessarily homogenously spread through the epilimnion. Furthermore, calculation of simple ecologically relevant metrics based on mixed depth showed that these metrics were highly dependent on the definition of mixed depth used. The results demonstrate that an idealised concept of a well-defined fully mixed layer is not necessarily appropriate. The widespread use of multiple definitions for mixed depth impairs the comparability of different studies while associated uncertainty over the most appropriate definition limits the confirmability of studies utilising the mixed depths. (C) 2019 Elsevier Ltd. All rights reserved.