Variations in tropical west Pacific climate and its role in glacial-interglacial cycles

热带西太平洋气候变化及其在冰期-间冰期循环中的作用

• 批准号: 46919636
• 负责人: Professorin Dr. Anna Nele Meckler
• 金额: --
• 依托单位: Institutt for geovitenskap
• 依托单位国家: 德国
• 项目类别: Research Fellowships
• 财政年份: 2007
• 资助国家: 德国
• 起止时间: 2006-12-31 至 2010-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/46919636?language=en
• 关键词: Variations; tropical; west; Pacific; climate

The tropical oceans are a major source of heat and moisture for the high latitudes, making them a key player in the global climate system. Under modern climate conditions, strong inter-annual variability in tropical climate related to El Niño-Southern Oscillation has been observed, which affects climate in the surrounding land masses and also worldwide. While this phenomenon has been well studied for the present-day, the behavior of tropical climate on longer timescales and its role during large global climate shifts is not yet well understood. In the proposed study, we will use stalagmites from Borneo as archives to assess past changes in precipitation and temperature in the tropical west Pacific, covering several glacial-interglacial cycles. Variations in the hydrological cycle will be reconstructed from changes in the oxygen isotopic composition of calcite. As stalagmites allow continuous reconstructions at very high resolution, the proposed work should yield a paleoclimate record that permits assessing not only changes in the mean state but also in the variability of climate. Furthermore, precise age control through U-series dating will allow examining the relative timing of changes in tropical climate in comparison to higher latitudes. In addition to the well-established oxygen isotope approach, we propose to apply two new methods to the stalagmites, namely NanoSIMS for ultra-high resolution measurements of elemental (and potentially isotopic) ratios and a recently proposed paleothermometer based on carbonate isotopologues. The proposed study will therefore both contribute a valuable paleoclimate record and expand the toolbox of paleoclimatologists.

热带海洋是高纬度的主要热和水分来源，使它们成为全球气候系统的关键参与者。在现代气候条件下，已经观察到与厄尔尼诺南部振荡相关的热带气候的强烈年际变化，这会影响周围土地群体和全球范围内的气候。尽管这种现象在当今已经很好地研究了，但热带气候在更长的时间标准及其在全球气候变化中的作用尚未得到充分了解。在拟议的研究中，我们将使用来自婆罗洲的石匠作为档案，以评估热带西太平洋的降水和温度的过去变化，涵盖了几个冰川间 - 冰川循环。水文循环的变化将从钙的氧同位素组成的变化中重建。由于水生条允许在非常高分辨率的情况下进行连续重建，因此拟议的工作应产生古气候记录，该记录允许评估平均状态的变化，而且允许在气候变化中进行变化。此外，与较高的纬度相比，通过U系列日期控制的精度年龄控制将允许检查热带气候变化的相对时机。除了完善的氧同位素方法外，我们还建议将两种新方法应用于静态，即纳米菌对元素（和潜在同位素）比的超高分辨率测量以及最近提出的基于碳酸盐同位素同位素的元素比率计。因此，拟议的研究将构成有价值的古气候记录，并扩大古气候学家的工具箱。