Interannual variability of the Subpolar Mode Water properties over the Reykjanes Ridge during 1990–2006
Interannual variability of the Subpolar Mode Water properties over the Reykjanes Ridge during 1990–2006
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1990-2006 年雷克雅内斯海脊副极地模式水特性的年际变化
DOI：
10.1029/2007jc004443
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发表时间：
2008
影响因子：
--
通讯作者：
H. Mercier
中科院分区：
文献类型：
--
作者：
V. Thierry;E. Boisséson;H. Mercier
结合水文数据从OVIDE（天文台de la Variabilite Interannuelle a Decennale/天文台的年际到十年变化）部分（格陵兰，葡萄牙）与阿尔戈和历史CTD数据在1990年至2006年期间，我们估计的变化的各种次极地模式水（SPMW）观测的雷克雅内斯海脊东侧的核心属性。该SPMW在雷克雅未克海脊东侧沿着冬季混合层中获得其核心特性。我们发现，二月海表温度沿着脊是其核心温度的代理。这种模式的水的来源是在冰岛盆地的平均气旋环流平流水团。在20世纪90年代初，观察到了SPMW堆芯性能冷却和清新的密度补偿趋势。它在1996年停止，随后温度和盐度升高（+1.41 ° C和+0.11 psu），密度下降（-0.12 kg m−3），直到至少2003年。在整个期间，数据没有显示任何重大修改的模式水核心的深度，而他们建议的层的厚度收缩。当地的海气淡水和热通量的变化不能解释观测到的盐度和温度的变化。它们最有可能与SPMW源的属性的修改，由于最近证明的变化，驱动北大西洋涛动，在亚热带沃茨和亚极地沃茨在冰岛盆地的相对贡献。
Combining hydrographic data from the OVIDE (Observatoire de la Variabilite Interannuelle a Decennale/Observatory of the Interannual to Decadal Variability) section (Greenland-Portugal) with Argo and historical CTD data over the period 19902006, we estimate the variability of the core properties of a variety of Subpolar Mode Water (SPMW) observed on the eastern flank of the Reykjanes Ridge. This SPMW acquires its core properties in the winter mixed layer along the eastern side of the Reykjanes Ridge. We find that the February sea surface temperature along the ridge is a proxy for its core temperature. The sources of this mode water are water masses advected by the mean cyclonic circulation in the Iceland Basin. A density compensated tendency for cooling and freshening of the SPMW core properties is observed in the early 1990s. It stops in 1996 and is followed by an increase in temperature and salinity (+1.41°C and +0.11 psu) and a decrease in density (−0.12 kg m−3) until at least 2003. During the entire period, the data do not show any significant modification in the depth of the mode water core while they suggest that the thickness of the layer shrank. The variability of the local air-sea freshwater and heat fluxes cannot explain the observed salinity and temperature variations. They are most likely related to the modifications of the properties of the SPMW sources due to the recently evidenced changes, driven by the North Atlantic Oscillation, in the relative contributions of subtropical waters and subpolar waters in the Iceland Basin.