Glacial water mass geometry and the distribution of δ13C of ΣCO2 in the western Atlantic Ocean -: art. no. PA1017
Glacial water mass geometry and the distribution of δ13C of ΣCO2 in the western Atlantic Ocean -: art. no. PA1017
复制标题
DOI：
10.1029/2004pa001021
复制
发表时间：
2005-03-18
期刊：
影响因子：
--
通讯作者：
Oppo, DW
中科院分区：
文献类型：
--
作者：
Curry, WB;Oppo, DW
从巴西边缘的25个新活塞岩心、重力岩心和多岩心中获得了底栖有孔虫类群Cibicidoides和Planulina的氧和碳同位素数据。岩芯跨越水深约400至3000米，并与该区域的主要水团相交。这些新数据填补了南大西洋的一个关键空白，并为更新Duplessy等人（1988年）的经典冰川西大西洋三角洲C-13样带提供了动力。Sigma CO2的δ C-13的分布需要在大西洋冰川中存在三个不同的水团：浅（类似于1000 m），南部水源水团，端元d（13）C值约为0.3- 0.5%VPDB，（类似于1500 m），北方源水团，端元值约为1.5%（0），（> 2000米），南部水源的端元值小于-0.2%，可能低至南大洋南大西洋部分观测到的-0.9%（0）值（Ninnemann和Charles，2002年）。水团的起源是由底栖有孔虫三角洲O-18的纬向梯度支持的。深水三角洲C-13的冰川部分的修订文件的位置和梯度之间的这些端员中间和深水群众。在强垂直混合存在下的大性质梯度只能通过强翻转环流来维持。
Oxygen and carbon isotopic data were produced on the benthic foraminiferal taxa Cibicidoides and Planulina from 25 new piston cores, gravity cores, and multicores from the Brazil margin. The cores span water depths from about 400 to 3000 m and intersect the major water masses in this region. These new data fill a critical gap in the South Atlantic Ocean and provide the motivation for updating the classic glacial western Atlantic delta C-13 transect of Duplessy et al. ( 1988). The distribution of delta C-13 of Sigma CO2 requires the presence of three distinct water masses in the glacial Atlantic Ocean: a shallow (similar to 1000 m), southern source water mass with an end-member d(13)C value of about 0.3-0.5% VPDB, a middepth (similar to 1500 m), northern source water mass with an end-member value of about 1.5%(0) and a deep (> 2000 m), southern source water with an end-member value of less than -0.2%, and perhaps as low as the -0.9%(0) values observed in the South Atlantic sector of the Southern Ocean (Ninnemann and Charles, 2002). The origins of the water masses are supported by the meridional gradients in benthic foraminiferal delta O-18. A revised glacial section of deep water delta C-13 documents the positions and gradients among these end-member intermediate and deep water masses. The large property gradients in the presence of strong vertical mixing can only be maintained by a vigorous overturning circulation.