Quantifying Antarctic Bottom Water and North Atlantic Deep Water volumes
Quantifying Antarctic Bottom Water and North Atlantic Deep Water volumes
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DOI：
10.1029/2007jc004477
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发表时间：
2008-05-23
影响因子：
3.6
通讯作者：
Johnson, Gregory C.
中科院分区：
文献类型：
--
作者：
Johnson, Gregory C.
通过对保守和准保守海水性质的非负最小二乘分析，对南极底层水(AABW)和北大西洋深水(NADW)进行了近全球普查。受海洋水深测量的影响，AABW厚度一般由南向北递减。同样，在大西洋，NADW厚度通常从北到南递减。NADW在大西洋温跃层以下占据主导地位，至少远至南大西洋的副热带环流，对整个南极绕极洋流、印度洋和太平洋的影响较小，但仍然很大。然而，在太平洋和印度洋，AABW在温跃层以下占主导地位。此外，可测量的AABW进入大西洋中部海脊两侧的深海北大西洋。普查结果表明，AABW在三个主要大洋的体积大约是NADW的两倍，与NADW相比，AABW接触的深度主海底面积大约是NADW的两倍。然而，这些结果对水团的选择、它们的海水属性值以及分析中使用的海水属性的权重都有一定的敏感性。
A near-global census of Antarctic Bottom Water (AABW) and North Atlantic Deep Water (NADW) is essayed through a nonnegative least squares analysis of conservative and quasi-conservative seawater properties. AABW thickness generally decreases from south to north, modulated by ocean bathymetry. Likewise, NADW thickness generally decreases from north to south in the Atlantic Ocean. NADW dominates below the thermocline of the Atlantic Ocean at least as far south as the subtropical gyre of the South Atlantic, with a lesser, but still significant, influence around the entire Antarctic Circumpolar Current, in the Indian Ocean, and in the Pacific Ocean. However, in the Pacific and Indian oceans, AABW dominates below the thermocline. In addition, measurable quantities of AABW reach into the abyssal North Atlantic on both sides of the mid-Atlantic Ridge. The census results suggest that AABW occupies roughly twice the volume of NADW in the three main oceans, and that AABW is in contact with roughly twice the area of the deep main ocean floor compared with NADW. However, these results are somewhat sensitive to choices of water masses, their values of seawater properties, and the weightings of the seawater properties used in the analysis.