The behaviour of iron and other trace elements during the IronEx-I and PlumEx experiments in the Equatorial Pacific
The behaviour of iron and other trace elements during the IronEx-I and PlumEx experiments in the Equatorial Pacific
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DOI：
10.1016/s0967-0645(98)00012-5
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发表时间：
1998-01-01
影响因子：
3
通讯作者：
Coale, KH
中科院分区：
文献类型：
--
作者：
Gordon, RM;Johnson, KS;Coale, KH
1993年10月和11月，在加拉帕戈斯群岛附近进行了IronEx I和PlumEx实验，测量了溶解（< 0.4 μ m）和颗粒（0.4-5 μ m和0.5 μ m，可浸出和难浸）微量元素。在施肥后的9天内，在富集区和对照站测量铁含量。溶解的铁最初以铁的半衰期为28-40小时的速度耗尽。损失率逐渐降低，在整个实验过程中，溶解的铁浓度没有低于0.25 nmol kg（-1）。这些结果与一个动力学模型是最一致的，在二级的铁浓度清除去除每个铁馏分。在IronEx I试验期间，所测得的其他微量元素的浓度和分配都没有显著变化。随着时间的推移，生物产量跟踪铁浓度，这表明受精地块内的生产力是由铁的可用性调节的。PlumEx研究主要由两个断面组成，加拉帕戈斯群岛东部的经向部分和西部的纬向部分。除加拉帕戈斯群岛附近的监测站外，所有监测站的地表溶解铁含量都很低。痕量金属的部分和其他性质清楚地证实了赤道暗流在与岛屿相交时的上升流。这种上升流对岛屿西侧微量金属的表面分布有很大的影响。该地区混合层内的生产力与铁和硝酸盐高度相关。在岛屿的西部，生产力最高的地方是铁含量最高的地方。在赤道锋以北，在硝酸盐枯竭的水域，铁浓度升高并不能提高生产力。1998爱思唯尔科学有限公司版权所有。
Dissolved (< 0.4 mu m) and particulate (0.4-5 mu m and >5 mu m, leachable and refractory) trace elements were measured during the IronEx I and PlumEx experiments in October and November 1993 near the Galapagos Islands. Iron was measured in the enriched patch and at control stations over a 9 day period following fertilization. The dissolved iron was initially depleted at a rate that gave an iron half-life of 28-40 h. The loss rate gradually decreased, and dissolved iron concentrations did not decrease below about 0.25 nmol kg(-1) throughout the experiment. These results were most consistent with a kinetic model that was second order in iron concentration for the scavenging removal of each iron fraction. Other trace elements measured did not change significantly either in concentration or partitioning during the IronEx I experiment. Biological production tracked iron concentrations over time, which suggests that productivity within the fertilized patch was regulated by the availability of iron. The PlumEx study consisted primarily of two transects, a meridional course to the east of the Galapagos Islands and a zonal section to the west. Surface dissolved iron was very low at all stations except those near the Galapagos Islands. Sections of trace metal and other properties distinctly confirm the upwelling of the Equatorial Undercurrent as it intersects the islands. This upwelling has a great effect on the surface distributions of the trace metals on the west side of the islands. Productivity within the mixed layer of this region is highly correlated with iron and nitrate. West of the islands highest productivity is found at stations with the highest iron. North of the Equatorial front, in nitrate-depleted waters, elevated iron concentrations do not enhance productivity. (C) 1998 Elsevier Science Ltd. All rights reserved.