Local and Downstream Relationships between Labrador Sea Water Volume and North Atlantic Meridional Overturning Circulation Variability
Local and Downstream Relationships between Labrador Sea Water Volume and North Atlantic Meridional Overturning Circulation Variability
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DOI：
10.1175/jcli-d-18-0735.1
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发表时间：
2019-07-01
影响因子：
4.9
通讯作者：
Zhang, Rong
中科院分区：
文献类型：
--
作者：
Li, Feili;Lozier, M. Susan;Zhang, Rong
虽然人们普遍认为拉布拉多海水（LSW）的产生会影响大西洋纬向翻转环流（MOC），但这种关系尚未得到广泛探讨或验证。为了探索这种关系，一套全球海洋海冰模式被迫相同的年际变化的大气数据集，不同的分辨率从非涡允许的涡允许（18-1/ 48），进行了分析，以调查本地和下游之间的关系LSW的形成和MOC年际到十年的时间尺度。虽然所有的模型显示LSW量和MOC在拉布拉多海的变化之间有很强的关系，这种关系大大降低拉布拉多海下游。特别是，在北大西洋副热带海盆的模式之间没有一致的模式在年际到十年的时间尺度。此外，强烈的响应MOC在拉布拉多海LSW量的变化，在该盆地可能是有偏见的LSW在许多模型相比，观测生产过剩。这项分析表明，LSW量在拉布拉多海的变化不能明确和一致地联系到一个连贯的MOC响应跨纬度年际到十年的时间尺度在过去的半个世纪的海洋后报模拟。同样，没有连贯的关系之间的MOC和拉布拉多海混合层的深度或新形成的LSW的密度跨纬度或跨模型在年际到十年的时间尺度。
While it has generally been understood that the production of Labrador Sea Water (LSW) impacts the Atlantic meridional overturning circulation (MOC), this relationship has not been explored extensively or validated against observations. To explore this relationship, a suite of global ocean-sea ice models forced by the same interannually varying atmospheric dataset, varying in resolution from non-eddy-permitting to eddy-permitting (18-1/ 48), is analyzed to investigate the local and downstream relationships between LSW formation and the MOC on interannual to decadal time scales. While all models display a strong relationship between changes in the LSW volume and the MOC in the Labrador Sea, this relationship degrades considerably downstream of the Labrador Sea. In particular, there is no consistent pattern among the models in the North Atlantic subtropical basin over interannual to decadal time scales. Furthermore, the strong response of the MOC in the Labrador Sea to LSW volume changes in that basin may be biased by the overproduction of LSW in many models compared to observations. This analysis shows that changes in LSW volume in the Labrador Sea cannot be clearly and consistently linked to a coherent MOC response across latitudes over interannual to decadal time scales in ocean hindcast simulations of the last half century. Similarly, no coherent relationships are identified between theMOCand the Labrador Sea mixed layer depth or the density of newly formed LSW across latitudes or across models over interannual to decadal time scales.