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Tropical Climate Dynamics during the past Glacial/Interglacial Cycle in (sub)annual resolution (Cariaco Basin and Mexican Lakes)

过去冰川/间冰期循环期间的热带气候动态（次）年度分辨率（卡里亚科盆地和墨西哥湖）

基本信息

批准号：
12857089
负责人：
Professor Dr. Gerald Haug
金额：
--
依托单位：
Department of Earth Sciences
依托单位国家：
德国
项目类别：
Infrastructure Priority Programmes
财政年份：
2005
资助国家：
德国
起止时间：
2004-12-31 至 2007-12-31
项目状态：
已结题

来源：
https://gepris.dfg.de/gepris/projekt/12857089?language=en
关键词：
Tropical Climate Dynamics during past

项目摘要

The position of the Intertropical Convergence Zone (ITCZ) and the intensity of the Hadley circulation force tropical climate variability in Central America. Our proposed study locations sit within the area of seasonal change of the ITCZ position that determines the hydrological cycle and rainfall distribution in Mesoamerica. They range from the Cariaco Basin (off N Venezuela) across Yucatan and Central Mexico to the Pazific coast. We propose to obtain paleoclimate data from those marine and terrestrial sites located across gradients of precipitation. The reconstruction of tropical climate and ITCZ dynamics on a high-frequency scale (El-Nino-Southern Oscillation - ENSO, North Atlantic Oscillation - NAO) is pivitol to understand the role of the Tropics in global climate change. Therefore, we propose to obtain data in ultra-high time resolution from laminated sequences. We will apply a combination of laminae-based studies, non-destructive, continuous bulk sediment measurements (e.g. uXRF) and varve microfacies analyses. These data, together with radionuclide dates (14-C, 137-Cs, 210-Pb) and tephrochronology, form the basis for a robust, varve-based chronology. Our data has the potential to provide a new history of mean-state, frequency, and amplitude of ENSO, and to disentangle the interplay between high versus low latitude forcing of ITCZ dynamics in the region during the past Glacial/Interglacial cycle (the Cariaco Basin) and focused on the past 1000 yr (the Mexican lakes). We will discuss our paleoclimate data in light of the societal development in west Central Mexico and Yucatan.

热带辐合带（ITCZ）的位置和Hadley环流的强度对中美洲热带气候变率的影响。我们建议的研究地点位于ITCZ位置的季节变化区域内，该区域决定了中美洲的水文循环和降雨分布。它们的分布范围从卡里亚科盆地（委内瑞拉北部）穿过尤卡坦半岛和墨西哥中部到太平洋海岸。我们建议从跨越降水梯度的海洋和陆地站点获取古气候数据。在高频尺度（厄尔尼诺-南方涛动- ENSO，北大西洋涛动- NAO）上重建热带气候和ITCZ动力学是理解热带在全球气候变化中的作用的关键。因此，我们建议从层合序列中获得超高时间分辨率的数据。我们将结合层叠研究、非破坏性、连续的大块沉积物测量（如uXRF）和各种微相分析。这些数据，连同放射性核素年代（14-C、137- c、210-Pb）和温度年代学，构成了一个可靠的、基于变量的年代学基础。我们的数据有可能提供ENSO平均状态、频率和振幅的新历史，并解开过去冰期/间冰期（卡里亚科盆地）和过去1000年（墨西哥湖泊）期间该地区ITCZ动力学的高纬与低纬强迫之间的相互作用。我们将根据墨西哥中西部和尤卡坦半岛的社会发展来讨论我们的古气候数据。