Decline of surface temperature and salinity in the western tropical Pacific Ocean in the Holocene epoch
Decline of surface temperature and salinity in the western tropical Pacific Ocean in the Holocene epoch
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DOI：
10.1038/nature02903
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发表时间：
2004-09
期刊：
影响因子：
64.8
通讯作者：
L. Stott;K. Cannariato;R. Thunell;G. Haug;A. Koutavas;S. Lund
中科院分区：
文献类型：
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作者：
L. Stott;K. Cannariato;R. Thunell;G. Haug;A. Koutavas;S. Lund
在今天的气候中，热带太平洋西部的地表水盐度很低，向盆地东部增加。热带太平洋表层水的盐度被认为是由大气对流、降水、蒸发和海洋动力学共同控制的，在年际时间尺度上，显著的变化与厄尔尼诺/南方涛动循环有关。然而，对于海洋-大气耦合系统在几个世纪到几千年的时间尺度上的可变性，人们知之甚少。本文结合从热带太平洋西部三个沉积物柱样中提取的有孔虫的氧同位素和镁/钙数据，重建了该地区全新世的海面温度和盐度。我们发现，在过去的10,000∼年中，海面温度下降了0.5 °C，而海面盐度下降了∼1.5个实际盐度单位。我们的数据表明，太平洋盆地作为一个整体已经逐渐变得不那么咸了，或者赤道上目前的盐度梯度是相对较新的。
In the present-day climate, surface water salinities are low in the western tropical Pacific Ocean and increase towards the eastern part of the basin. The salinity of surface waters in the tropical Pacific Ocean is thought to be controlled by a combination of atmospheric convection, precipitation, evaporation and ocean dynamics, and on interannual timescales significant variability is associated with the El Niño/Southern Oscillation cycles. However, little is known about the variability of the coupled ocean–atmosphere system on timescales of centuries to millennia. Here we combine oxygen isotope and Mg/Ca data from foraminifers retrieved from three sediment cores in the western tropical Pacific Ocean to reconstruct Holocene sea surface temperatures and salinities in the region. We find a decrease in sea surface temperatures of ∼0.5 °C over the past 10,000 yr, whereas sea surface salinities decreased by ∼1.5 practical salinity units. Our data imply either that the Pacific basin as a whole has become progressively less salty or that the present salinity gradient along the Equator has developed relatively recently.