Methods of approximation influence aquatic ecosystem metabolism estimates
Methods of approximation influence aquatic ecosystem metabolism estimates
复制标题
近似方法影响水生生态系统代谢估计
DOI：
10.1002/lom3.10112
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发表时间：
2016
期刊：
影响因子：
--
通讯作者：
F. Ballantyne
中科院分区：
文献类型：
--
作者：
Chao Song;W. Dodds;Matt T. Trentman;Janine Rüegg;F. Ballantyne
水生态学家最近利用动力学模型来估计水生态系统的新陈代谢。所有的方法都涉及到数值求解描述溶解氧(DO)动力学的微分方程式。虽然DO微分方程可以用线性多步法或龙格-库塔法精确地求解，但精度较低的方法，如欧拉法，已经被应用。这些方法在如何使用离散的温度和光线测量来驱动DO动力学方面也有所不同。在这里，我们使用一个有代表性的数据流DO数据集来比较多种基于欧拉的方法和精确的数值方法产生的新陈代谢估计。我们还比较了使用光和温度的线性、分段常量和平滑样条线插值法估计的新陈代谢。在欧拉法中使用观测DO来计算DO饱和亏，与所有其他方法相比，新陈代谢估算结果有很大的不同。如果使用模拟DO来计算DO饱和亏缺，则欧拉法在新陈代谢估计中引入较小的误差，并且随着测井间隔的减小而减小。线性和平滑的样条线插值法可以得到相似的新陈代谢估计值，但不同于基于分段常数插值法的估计值。我们论证了不同的计算方法如何隐含着对过程和观测误差的不同假设，并得出结论：在观测误差的假设下，最佳实践是使用求解微分方程组的精确数值方法，并对光和温度进行连续内插。如果欧拉方法与频繁记录的数据配对，并且DO饱和亏损量是使用模拟DO计算的，则该方法将引入最小误差。
Aquatic ecologists have recently employed dynamic models to estimate aquatic ecosystem metabolism. All approaches involve numerically solving a differential equation describing dissolved oxygen (DO) dynamics. Although the DO differential equation can be solved accurately with linear multistep or Runge–Kutta methods, less accurate methods, such as the Euler method, have been applied. The methods also differ in how discrete temperature and light measurements are used to drive DO dynamics. Here, we used a representative stream DO data set to compare the metabolism estimates generated by multiple Euler based methods and an accurate numerical method. We also compared metabolism estimates using linear, piecewise constant and smoothing spline interpolation of light and temperature. Using observed DO to calculate DO saturation deficit in the Euler method results in a substantial difference in metabolism estimates compared to all other methods. If modeled DO is used to calculate DO saturation deficit, the Euler method introduces smaller error in metabolism estimates, which diminishes as logging interval decreases. Linear and smoothing spline interpolation result in similar metabolism estimates, but differ from estimates based on piecewise constant interpolation. We demonstrate how different computational methods imply distinct assumptions about process and observation error, and conclude that under the assumption of observation error, the best practice is to use the accurate numerical method of solving differential equation with a continuous interpolation of light and temperature. The Euler method will introduce minimal error if it is paired with frequently logged data and DO saturation deficit is computed using modeled DO.
影响因子：
2.7
作者：
Demars, Benoit O. L.;Thompson, Joshua;Manson, J. Russell
通讯作者：
Manson, J. Russell