Estimation of atmospheric nutrient inputs to the Atlantic Ocean from 50°N to 50°S based on large-scale field sampling: Iron and other dust-associated elements
Estimation of atmospheric nutrient inputs to the Atlantic Ocean from 50°N to 50°S based on large-scale field sampling: Iron and other dust-associated elements
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DOI：
10.1002/gbc.20062
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发表时间：
2013-09-01
影响因子：
5.2
通讯作者：
Ganzeveld, L.
中科院分区：
文献类型：
--
作者：
Baker, A. R.;Adams, C.;Ganzeveld, L.
矿物粉尘的大气输入为偏远的海洋提供铁和其他微量金属，并可能影响海洋碳循环，因为铁是一种潜在的限制性微量营养素。粉尘的产生、运输和沉积是高度异质的，很少有偏远的海洋地点粉尘浓度和化学（例如，铁溶解度）进行常规监测。在这里，我们使用的气溶胶和雨水样品收集在10个大规模的研究巡航估计大气输入的铁，铝，锰到大西洋的四个广泛的地区超过两个3 months期间为2001-2005年。我们估计，这些金属的总输入到我们的研究区域分别为4.2，17和0.27 Gmol的4月至6月和4.9，14和0.19 Gmol的9月至11月。在降雨量高的地区（热带辐合带和南大西洋风暴路径），输入量最高，降雨量占总输入量的比例较高，湿润地区。通过结合这些时间段的总金属和可溶性金属的输入估计值，我们计算了每种金属的溶解度总体百分比，这些金属占湿沉积和干沉积的贡献以及不同气溶胶类型的相对贡献。计算的溶解度范围为铁的2.4%-9.1%，铝的6.1%-15%，锰的54%-73%。我们讨论了我们的估计的不确定性来源，并将我们的结果与最近对大西洋大气铁输入的一些估计进行了比较。
Atmospheric inputs of mineral dust supply iron and other trace metals to the remote ocean and can influence the marine carbon cycle due to iron's role as a potentially limiting micronutrient. Dust generation, transport, and deposition are highly heterogeneous, and there are very few remote marine locations where dust concentrations and chemistry (e.g., iron solubility) are routinely monitored. Here we use aerosol and rainwater samples collected during 10 large-scale research cruises to estimate the atmospheric input of iron, aluminum, and manganese to four broad regions of the Atlantic Ocean over two 3month periods for the years 2001-2005. We estimate total inputs of these metals to our study regions to be 4.2, 17, and 0.27Gmol in April-June and 4.9, 14, and 0.19Gmol in September-November, respectively. Inputs were highest in regions of high rainfall (the intertropical convergence zone and South Atlantic storm track), and rainfall contributed higher proportions of total input to wetter regions. By combining input estimates for total and soluble metals for these time periods, we calculated overall percentage solubilities for each metal that account for the contributions from both wet and dry depositions and the relative contributions from different aerosol types. Calculated solubilities were in the range 2.4%-9.1% for iron, 6.1%-15% for aluminum, and 54%-73% for manganese. We discuss sources of uncertainty in our estimates and compare our results to some recent estimates of atmospheric iron input to the Atlantic.