Manganese in the eastern Atlantic Ocean: processes influencing deep and surface water distributions
Manganese in the eastern Atlantic Ocean: processes influencing deep and surface water distributions
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DOI：
10.1016/s0304-4203(98)00007-3
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发表时间：
1998-06
期刊：
影响因子：
3
通讯作者：
P. Statham;P. Yeats;W. Landing
中科院分区：
文献类型：
--
作者：
P. Statham;P. Yeats;W. Landing
1990 年 IOC 基线调查巡航东大西洋期间在四个垂直水柱站收集的样本，对溶解锰和总可溶解锰进行了分析。分布显示了该元素海洋分布的典型特征：表面升高（0.90–2.12 nM）和深水低浓度（低至约 0.2 nM）。这些新数据与大西洋、印度洋和太平洋其他地方的文献数据相结合，可以对水体中溶解锰的大时间和空间尺度去除进行检查。稳态深水浓度为 0.15 nM、去除速率常数为 0.015 yr−1 的一阶清除去除模型导致大约 400 年后背景锰浓度保持一致。水柱中的悬浮颗粒物具有比地壳物质更高的锰铝比，除非地壳物质的大气输入非常高或存在重要的底栖来源。在地表水柱中，来自撒哈拉沙漠的大气尘埃输入的作用显得非常重要，最高的锰浓度通常与最高尘埃输入的区域相关。然而，靠近北纬 12° 左右的非洲海岸，另一个锰来源似乎很重要，可能反映了该地区的底栖来源和上升流过程。
Samples collected at four vertical water column stations during the 1990 IOC baseline survey cruise in the eastern Atlantic Ocean, were analysed for dissolved and total dissolvable manganese. The distributions show the elevated surface (0.90–2.12 nM) and low deep water (down to ca. 0.2 nM) concentrations typical of the oceanic distribution of this element. This new data in combination with literature data from elsewhere in the Atlantic, Indian and Pacific Oceans, has allowed an examination of the large time and space scale removal of dissolved manganese from the water column. A first order scavenging removal model with a steady state deep water concentration of 0.15 nM, and a removal rate constant of 0.015 yr−1leads to a consistent background Mn concentration after about 400 years. Suspended particulate matter in the water column has a higher Mn to Al ratio than crustal material except where atmospheric inputs of crustal material are very high or significant benthic sources exist. In the surface water column, the role of atmospheric dust inputs from the Sahara desert appear very important, and highest Mn concentrations are generally associated with areas of highest dust input. However, closer to the African coast at about 12°N, another source of manganese appears to be important, and may reflect benthic sources and upwelling processes in the area.