Unified modelling of contrasting basin-scale dissolved Al distributions using dissolution kinetics of diatom aggregates.: implication for upwelling intensity as a primary factor to control opal burial rate.
Unified modelling of contrasting basin-scale dissolved Al distributions using dissolution kinetics of diatom aggregates.: implication for upwelling intensity as a primary factor to control opal burial rate.
复制标题
使用硅藻聚集体的溶解动力学对对比盆地规模溶解铝分布进行统一建模：上升流强度作为控制蛋白石埋藏率的主要因素的含义。
DOI：
10.1016/j.marchem.2021.104009
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发表时间：
2021
期刊：
影响因子：
3
通讯作者：
Nishino
中科院分区：
文献类型：
--
作者：
Akagi;T. H.;Nishino
溶解铝的分布强烈耦合硅藻硅藻细胞壳的溶解，因为蛋白石是溶解的海洋铝的主要清道夫。鉴于铝有一个更短的停留时间相比，草酸，垂直过程影响铝必须更重要。因此，通过Al的分布可以间接地了解硅藻硅藻壳的溶解行为。本文探讨了硅藻壳聚集体的溶解动力学特征，这种溶解动力学对于理解1）沉降颗粒中硅质部分的元素组成和2）蛋白石沉积的发生有限。硅藻硅藻壳聚集体的溶解动力学描述溶解作为聚集体大小的函数，其取决于硅藻生产力。为了提高我们的理解，一个一维模型已开发纳入溶解动力学。该模式模拟了大西洋、太平洋、北极和地中海的海盆尺度铝垂直剖面，并给出了蛋白石对铝的吸收参数，以及随硅浓度增加而增加的最大硅浓度和最小铝浓度。该模型预测了在较小/较大产量期间硅藻壳的有效溶解/埋藏。由于上升流触发硅藻的生产，我们建议，上升流强度的增加可能是最重要的参数，以减少海洋生物酸库存。
Distribution of dissolved aluminum is strongly coupled with dissolution of diatom frustules, since opal is the main scavenger of dissolved oceanic Al. Given Al has a much shorter residence time compared with silicic acid, vertical processes affecting Al must be much more important. It may therefore be possible to understand dissolution behavior of diatom frustules indirectly via Al distribution.In this paper, we explore the features that dissolution kinetics of diatom frustule aggregates would provide with respect to vertical profiles of silicic acid, opal and dissolved Al. This dissolution kinetics has merits to understand 1) the elemental composition of siliceous fraction of settling particles and 2) limited occurrence of opal deposition. The dissolution kinetics of diatom frustule aggregates describes dissolution as a function of aggregate size, which depends on diatom productivity. To heighten our understanding, a unidimensional model has been developed incorporating the dissolution kinetics. This model reproduces basin-scale Al vertical profiles in the Atlantic and Pacific Oceans and Arctic and Mediterranean Seas with the identical parameter of Al absorption by opal as well as maximum Si concentration and minimum Al concentration at increasing depths with increasing Si concentrations.The distribution of opal predicted by this model may be useful and may explain discrepancies between the observed and previously-modeled depth profiles for dissolved Al. This model predicts the effective dissolution/burial of frustules during periods of smaller/greater production. Because upwelling triggers the production of diatoms, we propose that increase in upwelling intensity may be most important parameters to reduce the oceanic silicic acid inventory.