Solar forcing of Florida Straits surface salinity during the early Holocene
Solar forcing of Florida Straits surface salinity during the early Holocene
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DOI：
10.1029/2012pa002284
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发表时间：
2012-09
期刊：
影响因子：
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通讯作者：
M. Schmidt;W. Weinlein;F. Marcantonio;J. Lynch‐Stieglitz
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文献类型：
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作者：
M. Schmidt;W. Weinlein;F. Marcantonio;J. Lynch‐Stieglitz
[1]以往的研究表明，海表盐度（SSS）在佛罗里达海峡，以及佛罗里达流传输与北大西洋气候的变化在过去的两千年共变。然而，很少有人知道更早的全新世水文变化在佛罗里达海峡。在这里，我们结合联合收割机镁/钙古温度计和稳定氧同位素测量的浮游有孔虫Globigerinoides ruber（白色品种），来自佛罗里达海峡沉积物岩心KNR 166 -2 JPC 51（24 � 24.70′ N，83 � 13.14′ W，198米深），以重建一个高分辨率（25年/样本）早中期全新世记录的海面温度和d 18 OSW（SSS的代理）的变化。去除全球d 18 OSW变化的影响，由于大陆冰体积的变化，我们发现，早全新世SSS富集与增加蒸发/降水比在佛罗里达海峡期间，减少太阳能强迫，增加冰筏碎片在北大西洋和发展更永久的厄尔尼诺现象在赤道太平洋东部的条件。当考虑到以前的高分辨率重建全新世热带大气环流变化，我们的研究结果提供的证据表明，在全新世早期太阳强迫的变化对全球热带水文循环产生了重大影响。
[1] Previous studies showed that sea surface salinity (SSS) in the Florida Straits as well as Florida Current transport covaried with changes in North Atlantic climate over the past two millennia. However, little is known about earlier Holocene hydrographic variability in the Florida Straits. Here, we combine Mg/Ca-paleothermometry and stable oxygen isotope measurements on the planktonic foraminifera Globigerinoides ruber (white variety) from Florida Straits sediment core KNR166–2 JPC 51 (24 � 24.70′ N, 83 � 13.14′ W, 198 m deep) to reconstruct a high-resolution (� 25 yr/sample) early to mid Holocene record of sea surface temperature and d 18 OSW (a proxy for SSS) variability. After removing the influence of global d 18 OSW change due to continental ice volume variability, we find that early Holocene SSS enrichments are associated with increased evaporation/precipitation ratios in the Florida Straits during periods of reduced solar forcing, increased ice rafted debris in the North Atlantic and the development of more permanent El Nino–like conditions in the eastern equatorial Pacific. When considered with previous high-resolution reconstructions of Holocene tropical atmospheric circulation changes, our results provide evidence that variations in solar forcing over the early Holocene had a significant impact on the global tropical hydrologic cycle.