• 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Global Biogeochemical Cycles >Surface ocean iron fertilization: The role of airborne volcanic ash from subduction zone and hot spot volcanoes and related iron fluxes into the Pacific Ocean
【24h】

Surface ocean iron fertilization: The role of airborne volcanic ash from subduction zone and hot spot volcanoes and related iron fluxes into the Pacific Ocean

机译：表层海洋铁肥：俯冲带和热点火山中的机载火山灰的作用以及进入太平洋的相关铁通量

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

Surface ocean iron (Fe) fertilization can affect the marine primary productivity (MPP), thereby impacting on CO_2 exchanges at the atmosphere-ocean interface and eventually on climate. Mineral (aeolian or desert) dust is known to be a major atmospheric source for the surface ocean biogeochemical iron cycle, but the significance of volcanic ash is poorly constrained. We present the results of geochemical experiments aimed at determining the rapid release of Fe upon contact of pristine volcanic ash with seawater, mimicking their dry deposition into the surface ocean. Our data show that volcanic ash from both subduction zone and hot spot volcanoes (n = 44 samples) rapidly mobilized significant amounts of soluble Fe into seawater (35-340 nmol/g ash), with a suggested global mean of 200 50 nmol Fe/g ash. These values are comparable to the range for desert dust in experiments at seawater pH (10-125 nmol Fe/g dust) presented in the literature (Guieu et al., 1996; Spokes et al., 1996). Combining our new Fe release data with the calculated ash flux from a selected major eruption into the ocean as a case study demonstrates that single volcanic eruptions have the potential to significantly increase the surface ocean Fe concentration within an ash fallout area. We also constrain the long-term (millennial-scale) airborne volcanic ash and mineral dust Fe flux into the Pacific Ocean by merging the Fe release data with geological flux estimates. These show that the input of volcanic ash into the Pacific Ocean (128-221 × 10~(15) g/ka) is within the same order of magnitude as the mineral dust input (39-519 × 10~(15) g/ka) (Mahowald et al., 2005). From the similarity in both Fe release and particle flux follows that the flux of soluble Fe related to the dry deposition of volcanic ash (3-75 × 10~9 mol/ka) is comparable to that of mineral dust (1-65 × 10~9 mol/ka). Our study therefore suggests that airborne volcanic ash is an important but hitherto underestimated atmospheric source for the Pacific surface ocean biogeochemical iron cycle.
机译：表层海洋铁（Fe）的施肥会影响海洋初级生产力（MPP），从而影响大气-海洋界面处的CO_2交换并最终影响气候。矿物（风尘或沙漠）粉尘是海洋表层海洋生物地球化学铁循环的主要大气来源，但火山灰的重要性受到了限制。我们提供了地球化学实验的结果，旨在确定原始火山灰与海水接触后铁的快速释放，从而模拟了它们在表层海洋中的干沉降。我们的数据表明，来自俯冲带和热点火山的火山灰（n = 44个样本）迅速将大量可溶性铁迁移到海水中（35-340 nmol / g灰分），建议的全球平均值为200 50 nmol Fe /灰。这些值与文献中提到的在海水pH值（10-125 nmol Fe / g灰尘）的实验中沙漠灰尘的范围相当（Guieu等，1996; Spokes等，1996）。结合案例研究，我们将新的铁释放数据与选定的主要火山喷发到海洋中的灰分通量计算得出的结果相结合，表明一次火山喷发有可能显着增加灰烬沉降区内地表海洋铁的浓度。通过将铁释放量数据与地质通量估算值合并，我们还限制了长期（千年尺度）的机载火山灰和矿物尘埃进入太平洋的铁通量。这些表明，火山灰向太平洋的输入量（128-221×10〜（15）g / ka）与矿物粉尘输入量（39-519×10〜（15）g / ka）处于同一数量级内。 ka）（Mahowald et al。，2005）。从铁释放和颗粒通量的相似性来看，与火山灰干沉降有关的可溶性铁通量（3-75×10〜9 mol / ka）与矿物粉尘的通量（1-65×10）相当。 〜9 mol / ka）。因此，我们的研究表明，机载火山灰是太平洋表层海洋生物地球化学铁循环的重要但至今仍被低估的大气源。

著录项

相似文献

  • 外文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号