Changes in the Ventilation of the Oxygen Minimum Zone of the Tropical North Atlantic
Changes in the Ventilation of the Oxygen Minimum Zone of the Tropical North Atlantic
复制标题
热带北大西洋最低氧区通风的变化
DOI：
10.1175/2010jpo4301.1
复制
发表时间：
2010
影响因子：
3.5
通讯作者：
Schmid
中科院分区：
文献类型：
--
作者：
Brandt;Hormann;Körtzinger;Visbeck;Krahmann;Stramma;Lumpkin;Schmid
利用1999-2008年期间在西经28.5°至23°之间进行的18次考察航次的海洋学资料以及1972-85年期间的历史数据，研究了热带北大西洋氧气最小区(OMZ)的通风变化。在大气层中心区400m深度处，在两个周期之间发现了非常显著的氧减少，约为15μ/kg−1。在同一时间间隔内，氧最低时的盐度增加了约0.1。在OMZ中心以上，中心水层内，氧气也减少，但盐度变化不大，甚至下降。局部氧-盐度关系中的离散度从前期到后期逐渐减小，表明由于中尺度涡旋和/或纬向急流作用于背景梯度而减少了丝状化。结果表明，在OMZ深度范围内观测到的几厘米/秒的纬向交替纬向急流对OMZ的通风有贡献。OMZ通风的概念性模式被用来证实纬向急流强度的变化影响OMZ中的平均氧水平的假设。根据该模型，纬向急流的减弱与观测到的水文证据基本一致，这与平均氧水平的降低有关，这可能对观测到的北大西洋OMZ的脱氧有显著贡献。
Changes in the ventilation of the oxygen minimum zone (OMZ) of the tropical North Atlantic are studied using oceanographic data from 18 research cruises carried out between 28.5° and 23°W during 1999–2008 as well as historical data referring to the period 1972–85. In the core of the OMZ at about 400-m depth, a highly significant oxygen decrease of about 15μmol kg−1is found between the two periods. During the same time interval, the salinity at the oxygen minimum increased by about 0.1. Above the core of the OMZ, within the central water layer, oxygen decreased too, but salinity changed only slightly or even decreased. The scatter in the local oxygen–salinity relations decreased from the earlier to the later period suggesting a reduced filamentation due to mesoscale eddies and/or zonal jets acting on the background gradients. Here it is suggested that latitudinally alternating zonal jets with observed amplitudes of a few centimeters per second in the depth range of the OMZ contribute to the ventilation of the OMZ. A conceptual model of the ventilation of the OMZ is used to corroborate the hypothesis that changes in the strength of zonal jets affect mean oxygen levels in the OMZ. According to the model, a weakening of zonal jets, which is in general agreement with observed hydrographic evidences, is associated with a reduction of the mean oxygen levels that could significantly contribute to the observed deoxygenation of the North Atlantic OMZ.
登录
查看更多内容
DOI：
--
发表时间：
1992
期刊：
影响因子：
--
作者：
M. Tsuchiya;L. Talley;M. Mccartney
通讯作者：
M. Mccartney
北大西洋东部副热带环流俯冲水的细观到大尺度结构
DOI：
--
发表时间：
1998
期刊：
影响因子：
--
作者：
T. Joyce;J. Luyten;A. Kubryakov;F. Bahr;Julie S. Pallant
通讯作者：
Julie S. Pallant
影响因子：
--
作者：
Brandt;V. Hormann;B. Bourles;J. Fischer;F. Schott;L. Stramma;M. Dengler
通讯作者：
M. Dengler
北大西洋佛得角群岛南部和东部的最低氧气区
影响因子：
--
作者：
Stramma;P. Brandt;J. Schafstall;F. Schott;J. Fischer;A. Körtzinger
通讯作者：
A. Körtzinger
影响因子：
5.2
作者：
P Brandt;F. Schott;C. Provost;A. Kartavtseff;Verena Hormann;B. Bourlès;J. Fischer
通讯作者：
P Brandt;F. Schott;C. Provost;A. Kartavtseff;Verena Hormann;B. Bourlès;J. Fischer