The Importance of Freshwater to Spatial Variability of Aragonite Saturation State in the Gulf of Alaska
The Importance of Freshwater to Spatial Variability of Aragonite Saturation State in the Gulf of Alaska
复制标题
淡水对阿拉斯加湾文石饱和状态空间变化的重要性
DOI：
10.1002/2017jc012791
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发表时间：
2017
影响因子：
--
通讯作者：
J. Mathis
中科院分区：
文献类型：
--
作者：
S. Siedlecki;D. Pilcher;A. Hermann;K. Coyle;J. Mathis
阿拉斯加湾（GOA）等高纬度和亚极地地区比赤道地区更容易受到二氧化碳水平上升的影响，部分原因是局部过程放大了全球信号。最近的野外观测表明，果阿大陆架目前正在经历季节性腐蚀事件（碳酸盐矿物饱和状态Ω， Ω<1），包括因海洋酸化而抑制的Ω，以及低碱度冰川融水排放增加等局部过程。冰川流量主要影响内陆架，而在外陆架，上升流则带来来自果阿区深部的腐蚀性水。在这项工作中，我们开发了一个高分辨率的GOA碳动力学模型，确定了Ω的高变率区域，并测试了这些区域对冰川融水排放化学变化的敏感性。结果表明，这种气候敏感且相对不受约束的区域淡水强迫对近岸Ω变率的重要性。在每100µmol/kg淡水径流碱度增加0.002 Ω时，其增加几乎是线性的。我们发现，当地的风、生物过程和淡水强迫都对Ω的空间分布有贡献，并确定这三个过程中哪一个与Ω的变率高度相关。考虑到这些过程的时间和强度在未来几十年可能会发生变化，使用诸如本文描述的强大模型来阐明当地过程对背景海洋酸化信号的影响至关重要。
High latitude and subpolar regions like the Gulf of Alaska (GOA) are more vulnerable than equatorial regions to rising carbon dioxide (CO2) levels, in part due to local processes that amplify the global signal. Recent field observations have shown that the shelf of the GOA is currently experiencing seasonal corrosive events (carbonate mineral saturation states Ω, Ω<1), including suppressed Ω in response to ocean acidification as well as local processes like increased low alkalinity glacial melt water discharge. While the glacial discharge mainly influences the inner shelf, on the outer shelf, upwelling brings corrosive waters from the deep GOA. In this work, we develop a high-resolution model for carbon dynamics in the GOA, identify regions of high variability of Ω, and test the sensitivity of those regions to changes in the chemistry of glacial melt water discharge. Results indicate the importance of this climatically sensitive and relatively unconstrained regional freshwater forcing for Ω variability in the nearshore. The increase was nearly linear at 0.002 Ω per 100 µmol/kg increase in alkalinity in the freshwater runoff. We find that the local winds, biological processes, and freshwater forcing all contribute to the spatial distribution of Ω and identify which of these three is highly correlated to the variability in Ω. Given that the timing and magnitude of these processes will likely change during the next few decades, it is critical to elucidate the effect of local processes on the background ocean acidification signal using robust models, such as the one described here.
DOI：
10.1016/j.jmarsys.2008.03.011
发表时间：
2009-02
期刊：
Journal of marine systems : journal of the European Association of Marine Sciences and Techniques
影响因子：
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作者：
C. Stow;J. Jolliff;D. McGillicuddy;S. Doney;J. Icarus Allen;Marjorie A.M. Friedrichs;Kenneth A. Rose;P. Wallhead
通讯作者：
C. Stow;J. Jolliff;D. McGillicuddy;S. Doney;J. Icarus Allen;Marjorie A.M. Friedrichs;Kenneth A. Rose;P. Wallhead
对比年份冰川排水对北极潮水冰川峡湾CO2系统和海洋酸化状态的影响
影响因子：
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作者：
Agneta Fransson;Melissa Chierici ;Daiki Nomura ;Mats Granskog ;Svein Kristiansen ;Tõnu Martma;Gernot Nehrke
通讯作者：
Gernot Nehrke