Controls on dissolved cobalt in surface waters of the Sargasso Sea: Comparisons with iron and aluminum
Controls on dissolved cobalt in surface waters of the Sargasso Sea: Comparisons with iron and aluminum
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DOI：
10.1029/2011gb004155
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发表时间：
2012-06
影响因子：
5.2
通讯作者：
R. Shelley;P. Sedwick;T. Bibby;Patricia Cabedo-Sanz;T. Church;Rodney J. Johnson;Anna I. Macey;C. Marsay;E. Sholkovitz;S. Ussher;P. Worsfold;M. Lohan
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文献类型：
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作者：
R. Shelley;P. Sedwick;T. Bibby;Patricia Cabedo-Sanz;T. Church;Rodney J. Johnson;Anna I. Macey;C. Marsay;E. Sholkovitz;S. Ussher;P. Worsfold;M. Lohan
2008年6月，在百慕大以南的一个纬向样带（北纬31°至24°）的水柱样本中测定了溶解钴（dCo）、铁（dFe）和铝（dAl）。观察到dFe（0.3-1.6 nM）和dAl（14-42 nM）的表面浓度普遍从北向南增加，表明气溶胶沉积是dFe和dAl的重要来源，而近表面dCo浓度没有观察到明显的趋势。船载气溶胶样品表明，气溶胶Co的溶解度分数值为8-100%，明显高于气溶胶Fe的溶解度（0.44-45%）的相应估计值。水文观测和分析的时间序列雨样本从百慕大表明，湿沉降占大部分（>80%）的总风成通量的钴，因此一个显着的比例的大气输入的dCo到我们的研究区域。我们的气溶胶数据意味着大气输入的dCo的马尾藻海是温和的，虽然这个通量可能是在夏末更显着。水柱dCo剖面揭示了一种垂直分布，主要反映了“营养型”行为，相对于dAl的清除型行为，以及dFe的营养型和清除型行为的混合。中尺度涡旋也似乎影响dCo的垂直分布。从上层水柱中生物去除dCo的效果明显，表现为明显的次表面最小值（21 ± 4 pM dCo），与原绿球藻丰度的最大值一致。这些意见意味着，原绿球藻中起着重要的作用，从真光区去除dCo，和dCo的可用性可能会调节原绿球藻生长在马尾藻海。
Dissolved cobalt (dCo), iron (dFe) and aluminum (dAl) were determined in water column samples along a meridional transect (∼31°N to 24°N) south of Bermuda in June 2008. A general north‐to‐south increase in surface concentrations of dFe (0.3–1.6 nM) and dAl (14–42 nM) was observed, suggesting that aerosol deposition is a significant source of dFe and dAl, whereas no clear trend was observed for near‐surface dCo concentrations. Shipboard aerosol samples indicate fractional solubility values of 8–100% for aerosol Co, which are significantly higher than corresponding estimates of the solubility of aerosol Fe (0.44–45%). Hydrographic observations and analysis of time series rain samples from Bermuda indicate that wet deposition accounts for most (>80%) of the total aeolian flux of Co, and hence a significant proportion of the atmospheric input of dCo to our study region. Our aerosol data imply that the atmospheric input of dCo to the Sargasso Sea is modest, although this flux may be more significant in late summer. The water column dCo profiles reveal a vertical distribution that predominantly reflects ‘nutrient‐type’ behavior, versus scavenged‐type behavior for dAl, and a hybrid of nutrient‐ and scavenged‐type behavior for dFe. Mesoscale eddies also appear to impact on the vertical distribution of dCo. The effects of biological removal of dCo from the upper water column were apparent as pronounced sub‐surface minima (21 ± 4 pM dCo), coincident with maxima in Prochlorococcus abundance. These observations imply that Prochlorococcus plays a major role in removing dCo from the euphotic zone, and that the availability of dCo may regulate Prochlorococcus growth in the Sargasso Sea.