在过去的175万年里,西太平洋温暖池的海面温度稳定
Thibault de Garidel-Thoron1, Yair Rosenthal, Franck Bassinot
1Institute of Marine and Coastal Sciences-Rutgers University, 71 Dudley Road, New Brunswick, New Jersey 08901, USA. garidel@marine.rutgers.edu
Nature
|January 22, 2005
概括
全球冷却可能无法解释普莱斯托纪中期气候过渡. 西太平洋温暖池中的海面温度保持稳定,这挑战了二氧化碳减少假设,并表明赤道太平洋温度对比度增加.
科学领域:
- 古气候学 古气候学
- 海洋学 海洋学 海洋学
- 海洋地质学海洋地质学
背景情况:
- 大约85万年前的普世中期气候过渡标志着冰川周期周期从41000年转变为10万年.
- 这种转变与全球冷却有关,可能是大气中二氧化碳 (CO2) 减少所导致的.
- 这种冷却的证据主要观察到赤道东部海洋上游地区,使热带温暖的游泳池研究较少.
研究的目的:
- 为了调查平纪期间西太平洋温暖池中的海面温度 (SST) 稳定性.
- 挑战目前普遍存在的假设,即大气中二氧化碳度下降是普莱斯托时代中期气候转变的主要驱动因素.
- 探索影响冰川周期变化的替代机制.
主要方法:
- 在过去的175万年中,重建了高分辨率的SST记录.
- 在浮游生物中利用氧同位素和Mg/Ca比率分析.
- 专注于来自西太平洋温暖池的沉积物核心.
主要成果:
- 来自西太平洋热水池的SST记录显示,在整个普莱斯托纪时期,SST的稳定性显著.
- 这种稳定性意味着热带净辐射预算的长期变化最小.
- 与东方赤道地区的发现相反,表明气候应对措施的区域差异.
结论:
- 这项研究挑战了一个假设,即大气二氧化碳的逐渐减少是85万年前后更长的冰川周期的主要触发因素.
- 结果表明,整个赤道太平洋的温度梯度增加.
- 这种放大温度对比可能显著影响了普莱斯托纪中期的气候过渡.
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