Subantarctic Mode Water Formation, Destruction, and Export in the Eddy-Permitting Southern Ocean State Estimate
Subantarctic Mode Water Formation, Destruction, and Export in the Eddy-Permitting Southern Ocean State Estimate
复制标题
DOI：
10.1175/jpo-d-12-0121.1
复制
发表时间：
2013-07-01
影响因子：
3.5
通讯作者：
Maze, Guillaume
中科院分区：
文献类型：
--
作者：
Cerovecki, Ivana;Talley, Lynne D.;Maze, Guillaume
使用 2005 年和 2006 年的数据同化、允许涡流的南大洋状态估计来检查亚南极模式水 (SAMW)。使用 Walin 分析来估计由海气浮力通量引起的表面形成，并通过 30 度南纬表面形成和输送之间的差异来诊断非密密混合，并考虑体积随时间的变化。密度范围为 26.5 < sigma < 27.1 kg m(-3) 的水（包括 SAMW）在所有三个海洋区域向北输出，净运输量为 (18.2, 17.1) Sv (1 Sv 10(6) m(3) s(-1)；2005、2006 年）；空气-海洋浮力通量形成 (13.2, 6.8) Sv，二重混合消除 (-14.5, -12.6) Sv，并且 (-19.3, -22.9) Sv 的体积损失主要发生在最强的 SAMW 形成位置。最活跃的 SAMW 形成是在印度洋，由海气浮力通量 (9.4, 10.9) Sv 形成，在那里它被二重混合 (-6.6, -3.1) Sv 部分破坏。对太平洋的出口强劲，在那里 SAMW 被海气浮力通量 (-1.1, -4.6) Sv 和二重混合 (-5.6, -8.4) Sv 破坏。在南大西洋，SAMW 由海气浮力通量 (5.0, 0.5) Sv 形成，并被二重混合 (-2.3, -1.1) Sv 破坏。海气通量形成的峰值出现在东南印度和东南太平洋 SAMW（SEISAMW、SEPSAMW）密度处。宽阔的 SAMW 环极露头窗口上的形成主要来自较稠密的水，由不同的淡水增益驱动，并通过加热或冷却而增加或减少。然而，在 SEISAMW 和 SEPSAMW 源区，地层是由较轻的水形成，由不同的热损失驱动。
Subantarctic Mode Water (SAMW) is examined using the data-assimilating, eddy-permitting Southern Ocean State Estimate, for 2005 and 2006. Surface formation due to air-sea buoyancy flux is estimated using Walin analysis, and diapycnal mixing is diagnosed as the difference between surface formation and transport across 30 degrees S, accounting for volume change with time. Water in the density range 26.5 < sigma < 27.1 kg m(-3) that includes SAMW is exported northward in all three ocean sectors, with a net transport of (18.2, 17.1) Sv (1 Sv 10(6) m(3) s(-1); for years 2005, 2006); air-sea buoyancy fluxes form (13.2, 6.8) Sv, diapycnal mixing removes (-14.5, -12.6) Sv, and there is a volume loss of (-19.3, -22.9) Sv mostly occurring in the strongest SAMW formation locations. The most vigorous SAMW formation is in the Indian Ocean by air-sea buoyancy flux (9.4, 10.9) Sv, where it is partially destroyed by diapycnal mixing (-6.6, -3.1) Sv. There is strong export to the Pacific, where SAMW is destroyed both by air-sea buoyancy flux (-1.1, -4.6) Sv and diapycnal mixing (-5.6, -8.4) Sv. In the South Atlantic, SAMW is formed by air-sea buoyancy flux (5.0, 0.5) Sv and is destroyed by diapycnal mixing (-2.3, -1.1) Sv. Peaks in air-sea flux formation occur at the Southeast Indian and Southeast Pacific SAMWs (SEISAMWs, SEPSAMWs) densities. Formation over the broad SAMW circumpolar outcrop windows is largely from denser water, driven by differential freshwater gain, augmented or decreased by heating or cooling. In the SEISAMW and SEPSAMW source regions, however, formation is from lighter water, driven by differential heat loss.