EMPOWER-1.0: an Efficient Model of Planktonic ecOsystems WrittEn in R
EMPOWER-1.0: an Efficient Model of Planktonic ecOsystems WrittEn in R
复制标题
DOI：
10.5194/gmd-8-2231-2015
复制
发表时间：
2015-01-01
影响因子：
5.1
通讯作者：
Yool, A.
中科院分区：
文献类型：
--
作者：
Anderson, T. R.;Gentleman, W. C.;Yool, A.
在决定适当的模型结构、方程式和参数时，海洋生态系统模型需要洞察力和判断力。许多过程相对来说知之甚少，必须做出坚韧的决定，如何在数学上简化真实的世界。在这里，我们提出了一个有效的浮游生物建模测试平台，EMPOWER-1.0（有效的浮游生态系统模型R），在免费提供的语言R编码。该试验台使用简单的两层“板”物理学，其中包含浮游海洋生态系统的季节性变化的混合层位于仅包含营养物的深层之上。因此，EMPOWER-1.0为评估模型结构、公式和参数化提供了一个随时可用且易于使用的工具。代码是透明的和模块化的，因此可以轻松实现对模型公式的修改和更改，允许用户调查和熟悉其模型的内部工作原理。它可以用于初步模型测试，为进一步的工作奠定基础，例如将生态系统模型与1-D或3D物理耦合，或自行进行前线研究。EMPOWER-1.0也是一个理想的教学工具。为了证明EMPOWER-1.0的实用性，我们实现了一个简单的营养盐-浮游植物-浮游动物-浮游生物（NPZD）生态系统模型，并进行了参数调整和结构敏感性分析。四个对比鲜明的海洋网站，集中在站BIOTRANS在北大西洋（47度N，20度W），参数调整进行了演示，突出了两个效用进行计划的敏感性分析，为此目的，但也是主观性，但围绕选择哪些参数调整。结构敏感性测试，然后进行比较不同的方程计算每日深度综合光合作用，以及浮游植物和浮游动物的死亡率。以日光合作用的计算为例，结果表明，该模型对光合作用-辐照曲线的选择相对不敏感，但对水柱中光衰减的计算方法却非常敏感。这项工作突出了EMPOWER-1.0作为理解、诊断和制定海洋生态系统动态方程的一种手段的效用。
Modelling marine ecosystems requires insight and judgement when it comes to deciding upon appropriate model structure, equations and parameterisation. Many processes are relatively poorly understood and tough decisions must be made as to how to mathematically simplify the real world. Here, we present an efficient plankton modelling testbed, EMPOWER-1.0 (Efficient Model of Planktonic ecOsystems WrittEn in R), coded in the freely available language R. The testbed uses simple two-layer "slab" physics whereby a seasonally varying mixed layer which contains the planktonic marine ecosystem is positioned above a deep layer that contains only nutrient. As such, EMPOWER-1.0 provides a readily available and easy to use tool for evaluating model structure, formulations and parameterisation. The code is transparent and modular such that modifications and changes to model formulation are easily implemented allowing users to investigate and familiarise themselves with the inner workings of their models. It can be used either for preliminary model testing to set the stage for further work, e.g. coupling the ecosystem model to 1-D or 3D physics, or for undertaking front line research in its own right. EMPOWER-1.0 also serves as an ideal teaching tool. In order to demonstrate the utility of EMPOWER-1.0, we implemented a simple nutrient-phytoplankton-zooplanktondetritus (NPZD) ecosystem model and carried out both a parameter tuning exercise and structural sensitivity analysis. Parameter tuning was demonstrated for four contrasting ocean sites, focusing on station BIOTRANS in the North Atlantic (47 degrees N, 20 degrees W), highlighting both the utility of undertaking a planned sensitivity analysis for this purpose, yet also the subjectivity which nevertheless surrounds the choice of which parameters to tune. Structural sensitivity tests were then performed comparing different equations for calculating daily depth-integrated photosynthesis, as well as mortality terms for both phytoplankton and zooplankton. Regarding the calculation of daily photosynthesis, for example, results indicated that the model was relatively insensitive to the choice of photosynthesis-irradiance curve, but markedly sensitive to the method of calculating light attenuation in the water column. The work highlights the utility of EMPOWER-1.0 as a means of comprehending, diagnosing and formulating equations for the dynamics of marine ecosystems.