Assessing the apparent imbalance between geochemical and biochemical indicators of meso- and bathypelagic biological activity: What the @$#! is wrong with present calculations of carbon budgets?
Assessing the apparent imbalance between geochemical and biochemical indicators of meso- and bathypelagic biological activity: What the @$#! is wrong with present calculations of carbon budgets?
复制标题
DOI：
10.1016/j.dsr2.2010.02.022
复制
发表时间：
2010-08-15
影响因子：
3
通讯作者：
Tanaka, Tsuneo
中科院分区：
文献类型：
--
作者：
Burd, Adrian B.;Hansell, Dennis A.;Tanaka, Tsuneo
真光层以下水体中的代谢活动最终是由表面有机物质的垂直通量推动的。随着时间的推移，深海可能处于稳定状态，源汇平衡。但最近编制的全球预算和密集的当地实地研究表明，对黑暗海洋新陈代谢活动的估计超过了有机底物的流入。这种不平衡表明，要么存在下落不明的有机碳来源，要么是黑暗海洋中的代谢活动被高估了。暗海洋中有机碳通量和代谢活动的预算存在与环境变异性、测量能力、转化参数和过程相关的不确定性，这些都没有得到很好的采样。我们提出了这些问题，并在可能的情况下量化了相关的不确定性，使用对已公布数据集的蒙特卡洛分析来确定这种不平衡可以完全由测量和转换因子的不确定性来解释的概率。敏感性分析表明，细菌生长效率和假定的细胞碳含量对碳失衡的程度影响最大。讨论了两个量化程度较低的来源，即颗粒物的横向平流和缓慢沉降的颗粒物群体，以此作为关闭区域碳收支的手段。最后，我们对未来的研究方向提出了建议，以减少重要的不确定性，并更好地确定碳预算失衡的规模和原因。(C)2010爱思唯尔有限公司。保留所有权利。
Metabolic activity in the water column below the euphotic zone is ultimately fuelled by the vertical flux of organic material from the surface. Over time, the deep ocean is presumably at steady state, with sources and sinks balanced. But recently compiled global budgets and intensive local field studies suggest that estimates of metabolic activity in the dark ocean exceed the influx of organic substrates. This imbalance indicates either the existence of unaccounted sources of organic carbon or that metabolic activity in the dark ocean is being over-estimated. Budgets of organic carbon flux and metabolic activity in the dark ocean have uncertainties associated with environmental variability, measurement capabilities, conversion parameters, and processes that are not well sampled. We present these issues and quantify associated uncertainties where possible, using a Monte Carlo analysis of a published data set to determine the probability that the imbalance can be explained purely by uncertainties in measurements and conversion factors. A sensitivity analysis demonstrates that the bacterial growth efficiencies and assumed cell carbon contents have the greatest effects on the magnitude of the carbon imbalance. Two poorly quantified sources, lateral advection of particles and a population of slowly settling particles, are discussed as providing a means of closing regional carbon budgets. Finally, we make recommendations concerning future research directions to reduce important uncertainties and allow a better determination of the magnitude and causes of the unbalanced carbon budgets. (C) 2010 Elsevier Ltd. All rights reserved.