The flux of bio- and lithogenic material associated with sinking particles in the mesopelagic "twilight zone" of the northwest and North Central Pacific Ocean
The flux of bio- and lithogenic material associated with sinking particles in the mesopelagic "twilight zone" of the northwest and North Central Pacific Ocean
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DOI：
10.1016/j.dsr2.2008.04.011
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发表时间：
2008-07-01
影响因子：
3
通讯作者：
Wilson, S.
中科院分区：
文献类型：
--
作者：
Lamborg, C. H.;Buesseler, K. O.;Wilson, S.
作为眩晕计划的一部分，我们使用系留和中性浮力沉积物捕捉器在大洋中层带的三个深度和两个生物地球化学对比地点(北太平洋在Aloha；北太平洋西部亚北极圈在K2)收集和分析下沉颗粒。这一努力是首次大规模使用中性浮力捕集器，也是海洋生物泵研究向前迈出的重要一步。在这篇文章中，我们介绍了对这些样品进行质量、大量营养素、生物矿物质和浮游植物色素测定的结果，并检查了各种潜在的收集偏差的影响，包括来自陷阱内颗粒降解、浮游动物游泳者和毒物的影响。虽然这些因素已经被观察到影响其他项目的结果，但我们发现它们对本研究中测量的通量的影响相对较小。然而，有证据表明，在一次部署中，中性浮力捕集器在通量精度方面比系留式捕集器表现得更好，这可能是因为提高了大颗粒的收集效率。通过中高层的物质通量呈现三种不同的模式：增加、减少和随深度恒定。在真光层中形成的所有生物源物质的通量都随深度递减。然而，通量随深度的衰减并不相同，浮游植物色素随深度的衰减最大，颗粒状无机碳的衰减最小。有机碳和有机氮在这些样品中表现出很高的相关性，几乎没有证据表明不同的衰减长度尺度。在两个测点和K2处，都观察到了颗粒物BA通量随深度的增加。Ba值的增加归因于降解颗粒中重晶石的形成，而K2处A1值的增加是大陆架/斜坡侧向输入的结果。在ALOHA观测到的A1通量随深度的变化是恒定的，通量似乎与大气沙尘沉积处于稳定状态。在K2观测到的中高层带对颗粒通量的衰减比在ALOHA要小。并且具有较高的PoC/PIC(雨)比。这两个因素结合在一起，意味着亚北极省的生物泵比我们占领期间的副热带涡旋效率高得多。这可能是大型浮游动物捕食产生的较快下沉颗粒的结果，也可能是天生较慢的颗粒降解率的结果。(C)2008爱思唯尔有限公司。保留所有权利。
As part of the VERTIGO program, we collected and analyzed sinking particles using tethered and neutrally buoyant sediment traps at three depths in the oceanic mesopelagic zone and at two biogeochemically contrasting sites (N. Central Pacific at ALOHA; N. Pacific Western Subarctic Gyre at K2). This effort represented the first large-scale use of neutrally buoyant traps and represents a significant step forward in the study of the marine biological pump. In this paper, we present the results of mass, macronutrient, biominerals and phytoplankton pigment determinations made on these samples.The impact of a variety of potential collection biases were examined, including those from in-trap particle degradation, zooplankton swimmers and poisons. Though these factors have been observed to affect results in other programs, we found them to have relatively little impact on measured fluxes in this study. There was evidence, however, that the neutrally buoyant traps performed better than the tethered traps in terms of flux accuracy during one deployment, possibly because of improved large particle collection efficiency.Fluxes of material exhibited three different patterns through the mesopelagic: increasing, decreasing and constant with depth. Decreasing fluxes with depth were observed for all biogenic material formed in the euphotic zone. The attenuation of flux with depth was not the same for all components, however, with phytoplankton pigments exhibiting the greatest degradation with depth and particulate inorganic carbon the least. Organic carbon and nitrogen showed a very high correlation in these samples, with little evidence of different attenuation length scales. Increasing fluxes with depth were observed for particulate Ba at both sites and All at K2. The increases in Ba are attributed to the formation of barite in degrading particles, while increasing A1 at K2 was the result of lateral inputs from a continental shelf/slope. Constant fluxes with depth were observed for A1 at ALOHA, where fluxes appeared to be in steady state with atmospheric dust deposition.The mesopelagic zone at K2 was observed to attenuate particle flux less than at ALOHA. and with a higher POC/PIC ("rain") ratio. These two factors combine to imply that the Subarctic province had a much more efficient biological pump than had the subtropical gyre during our occupations. This could be the result of either faster sinking particles, generated from grazing by large zooplankton, or inherently slower particle degradation rates. (C) 2008 Elsevier Ltd. All rights reserved.