Simple model of morphometric constraint on carbon burial in boreal lakes
Simple model of morphometric constraint on carbon burial in boreal lakes
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DOI：
10.3389/fenvs.2023.1101332
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发表时间：
2023-02
期刊：
影响因子：
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通讯作者：
B. Cael;D. Seekell
中科院分区：
文献类型：
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作者：
B. Cael;D. Seekell
提出了一种几何理论来解释北方湖泊碳埋藏与湖泊形状之间的经验关系。该模型的主要特点是衰减长度尺度，类似于海洋有机碳通量的模型。这个长度尺度是碳垂直位移的速度与呼吸的速度之比，并产生了一个简单的模型，该模型具有一个容易约束的自由参数。湖泊深度的分形面积体积关系，反映了近似尺度不变的地球地形上理想化的湖泊几何形状的基础上建模。碳埋藏是通过对这些深度应用衰减长度尺度来估计的。使用这个模型，我们证明了动态比率（通过表面积的平方根除以平均深度计算的湖泊形态测量指标）与碳埋藏之间的关系。我们使用缩放关系来预测动态比，并通过扩展碳埋藏，在整个湖泊大小谱的变化。我们的模型也提供了一个基础，概括的经验研究，生物群落规模。通过将我们的模型应用于北方湖泊普查，我们估计北方湖泊碳埋藏为1.8 ± 0.5 g C/m2/yr或1.1 ± 0.3 Tg C/yr。
A geometric theory was developed to explain the empirical relationship between carbon burial and lake shape in boreal lakes. The key feature of this model is an attenuation length scale, analogous to models of marine organic carbon fluxes. This length scale is the ratio of how fast carbon is displaced vertically versus how fast it is respired and engenders a simple model with a single easily constrained free parameter. Lake depths are modeled based on fractal area–volume relationships that reflect the approximate scale invariance of Earth’s topography on idealized lake geometries. Carbon burial is estimated by applying the attenuation length scale to these depths. Using this model, we demonstrate the relationship between the dynamic ratio—a metric of lake morphometry calculated by dividing the square root of surface area by the mean depth—and carbon burial. We use scaling relationships to predict how dynamic ratio, and by extension carbon burial, varies across the lake size spectrum. Our model also provides a basis for generalizing empirical studies to the biome scale. By applying our model to a boreal lake census, we estimate boreal lake carbon burial to be 1.8 ± 0.5 g C/m2/yr or 1.1 ± 0.3 Tg C/yr among all boreal lakes.