Variability and timing of Glacial-Interglacial productivitiy in the polar South and North Pacific - Implications for global climate development (PROPAC)

南太平洋和北太平洋极地冰期-间冰期生产力的变化和时间 - 对全球气候发展的影响 (PROPAC)

• 批准号: 131256038
• 负责人: Dr. Rainer Gersonde
• 金额: --
• 依托单位: Alfred-Wegener-Institut (AWI) Helmholtz-Zentrum für Polar- und Meeresforschung
• 依托单位国家: 德国
• 项目类别: Infrastructure Priority Programmes
• 财政年份: 2009
• 资助国家: 德国
• 起止时间: 2008-12-31 至 2010-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/131256038?language=en
• 关键词: Variability; timing; Glacial; Interglacial; productivitiy

The polar South and North Pacific represent prominent “high nutrient-low chlorophyll” (HNLC) areas of the World Ocean where phytoplankton productivity is rather low in spite of high macro-nutrient concentrations. This pattern has been related to the scarcity of micronutrients (e.g. iron) in these areas. Thus, the Pacific HNLC areas represent potential regions for increased productivity and related carbon sequestration resulting in a reduction of atmospheric CO2 concentration during climate periods when micro-nutrient deposition is enhanced via eolian or oceanic input. Although this mechanism may play a crucial role in the climate development, little is known about past productivity changes in the polar Pacific. In consideration of this gap in knowledge, we propose to a) reconstruct the timing and magnitude of glacial/interglacial variability of biological productivity in the polar South and North Pacific and reveal E-W gradients in relation to dust sources, sea ice extent and ocean ventilation over the past two terminations; and b) synchronize and compare the records with Greenland and Antarctic ice core CO2 and dust records to estimate response/role of polar Pacific HNLC areas to/in glacial climate development. The reconstruction will rely on a combined paleobiological (diatoms/ dinoflagellates/radiolarians) and geochemical (15Ndiat) approach. Core material will be recovered during RV Sonne cruise SO-202 (INOPEX) to the polar North Pacific (7.7.-28.8.09) and RV Polarstern cruise ANT-XXVI/2 (2.12.09-3.2.10) to the polar South Pacific. PROPAC will provide new data and paleoenvironmental scenarios, which can be used to better understand mechanisms amplifying climate variability related to CO2 sequestration and model their impact on global scale. With this PROPAC will tackle a topic that has been highlighted by IPCC 2007 as a major challenge in climate research.

极地南太平洋和北太平洋代表了世界海洋中突出的“高营养低叶绿素”（HNLC）区域，尽管宏观营养盐浓度很高，但浮游植物生产力相当低。这种情况与这些地区缺乏微量营养素（如铁）有关。因此，太平洋HNLC地区代表了潜在的地区，提高生产力和相关的碳固存，从而减少大气中的CO2浓度在气候期间，当微营养沉积是通过风成或海洋输入增强。虽然这种机制可能在气候发展中起着至关重要的作用，但人们对极地太平洋过去的生产力变化知之甚少。考虑到这一知识上的差距，我们建议：（1）重建南北太平洋极地生物生产力的冰期/间冰期变化的时间和幅度，揭示东西向梯度与过去两个终端的尘源、海冰范围和海洋通风的关系;和B）同步并比较记录与格陵兰和南极冰芯CO2和灰尘记录，以估计极地太平洋HNLC区域对/在冰川气候发展中的响应/作用。重建将依靠结合古生物学（硅藻/甲藻/放射虫）和地球化学（15 Ndiat）的方法。核心材料将在RV索内号SO-202（INOPEX）巡航至极地北太平洋（7.7.- 2009年8月28日至2010年2月23日）和前往南太平洋极地的“极地号”考察船ANT-XXVI/2号巡航（2009年12月28日至2010年2月3日）。PROPAC将提供新的数据和古环境情景，可用于更好地了解与CO2固存有关的放大气候变异的机制，并模拟其在全球范围的影响。有了这个PROPAC将解决一个主题，已经强调了IPCC 2007年作为一个重大的挑战，在气候研究。