Early Pleistocene formation of the asymmetric east-west pattern of upper water structure in the equatorial Pacific Ocean
Early Pleistocene formation of the asymmetric east-west pattern of upper water structure in the equatorial Pacific Ocean
复制标题
赤道太平洋早更新世东西向不对称上层海水结构格局的形成
DOI：
10.1007/s11434-011-4547-3
复制
发表时间：
2011-06
期刊：
影响因子：
--
通讯作者：
Jin HaiYan
中科院分区：
文献类型：
--
作者：
Jian ZhiMin;Guo JianQing;Cheng XinRong;Jin HaiYan
对大洋钻探计划（ODP）807号站点A孔上部43 m的表层和次表层生活的浮游有孔虫进行了稳定氧和碳同位素分析。通过与赤道东太平洋ODP 851站的资料对比，重建了2.5Ma以来赤道太平洋上层沃茨的古海洋学变化。在1.6- 1.4Ma期间，赤道西太平洋和赤道东太平洋的表层和次表层沃茨的氧同位素发生了显著变化，进一步证实了当时形成的不对称的东西向（E-W）格局。这一特征与现代赤道太平洋的纬向温度梯度（西高东低）和上层水结构不对称（西深东浅）相似。次表层水δ 18 O的纬向梯度变化大于表层水δ 18 O的纬向梯度变化，表明赤道太平洋非对称东西向分布型的形成与赤道东太平洋温跃层变浅和次表层水温显著降低有很大关系。此外，自1.6Ma以来，赤道太平洋表层和次表层沃茨的碳同位素差异明显减小，其长期偏心周期从400 ka变化到1.500 ka，反映了海洋碳库的重组。这可能是由于当时南大洋的深水重组及其对热带太平洋（特别是次表层水）的影响增强所致。我们的研究表明，热带海洋在全球气候变化中起着重要作用。
Surface- and subsurface-dwelling planktonic foraminifera from the upper 43 m of Hole A at the Ocean Drilling Program (ODP) Site 807, which was recovered from the western Pacific warm pool during ODP Leg 130, were analyzed for stable oxygen and carbon isotopes. By comparing these results with data from ODP Site 851 in the eastern equatorial Pacific, this study has reconstructed the paleoceanographic changes in upper ocean waters in the equatorial Pacific since 2.5 Ma. During the period from 1.6–1.4 Ma, the oxygen isotopes of surface and subsurface waters were found to markedly change in the western and eastern equatorial Pacific, further confirming the final formation of the well-defined asymmetric east-west (E-W) pattern at that time. This feature was similar to the zonal temperature gradient (sea surface temperature is higher in the west and lower in the east) and the asymmetric upper water structure (thermocline depth is deeper in the west and shallower in the east) in the modern equatorial Pacific. The zonal gradient change of subsurface waterδ18O was greater than that of surface waterδ18O, indicating that the formation of the asymmetric E-W pattern in the equatorial Pacific should be much more related to the shoaled thermocline and markedly decreased subsurface water temperature in the eastern equatorial Pacific. Moreover, since ∼1.6 Ma, the carbon isotopic differences between surface and subsurface waters clearly decreased in the equatorial Pacific, and their long-term eccentricity periods changed from 400 ka to ∼500 ka, reflecting the reorganization of the ocean carbon reservoir. This probably resulted from the deep water reorganization in the Southern Ocean at that time and its enhanced influence on the tropical Pacific (especially subsurface water). Our study demonstrates that the tropical ocean plays an important role in global climate change.
登录
查看更多内容
影响因子：
--
作者：
Jun Tian;Pinxian Wang;Ronghua Chen;Xinrong Cheng
通讯作者：
Jun Tian;Pinxian Wang;Ronghua Chen;Xinrong Cheng
影响因子：
56.9
作者：
M. Wara;A. Ravelo;M. Delaney
通讯作者：
M. Wara;A. Ravelo;M. Delaney
影响因子：
5.3
作者：
Jian, ZM;Wang, PX;Cheng, XR
通讯作者：
Cheng, XR
影响因子：
5.3
作者：
Jian Xu;A. Holbourn;W. Kuhnt;Z. Jian;H. Kawamura
通讯作者：
Jian Xu;A. Holbourn;W. Kuhnt;Z. Jian;H. Kawamura
影响因子：
--
作者：
Pinxian Wang;Jun Tian;Xinrong Cheng;Chuanlian Liu;Jian Xu
通讯作者：
Pinxian Wang;Jun Tian;Xinrong Cheng;Chuanlian Liu;Jian Xu