The Black Carbon Cycle: Budget and Fluxes of Black Carbon in South Atlantic Sediments

黑碳循环：南大西洋沉积物中黑碳的预算和通量

• 批准号: 0851044
• 负责人: Rainer Lohmann
• 金额: $ 39.25万
• 依托单位: University of Rhode Island
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-07-01 至 2013-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0851044&HistoricalAwards=false
• 关键词: Black; Carbon; Cycle; Budget; Fluxes

This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5).In this study, researchers at the University of Rhode Island will attempt to determine the origin and fluxes of black carbon (BC) in marine sediments from the South Atlantic. Black carbon in the atmosphere is a key driver of global climate change; it is second only to CO2 in its contribution to global warming. The proposed work is thus relevant and timely for our understanding of the carbon cycle, a key component of our ability to forecast climate and its change. The major sources of BC on the global scale are fossil fuel and biomass burning, which are both prominent in Africa and South America. Hence, it is proposed to account for soot BC, char and charcoal residing in sediments from the South Atlantic by combining thermal, chemical and petrographic isolation methods.This project has three main hypotheses: (1) Soot BC constitutes a significant fraction of the total organic carbon in deep sea sediments of the South Atlantic, and dominates total BC in those sediments; (2) Biomass burning is the dominant source of the soot BC present in deep sea sediments of the South Atlantic; and (3) For the South Atlantic, atmospheric deposition of soot BC is as important as riverine inputs.This study represents a first attempt to account for BC sinks on an Ocean scale. It thus holds promise to make a major step forward towards being able to mass balance sources and sinks of BC. Previous studies suggest that BC reaches the oceans predominantly from riverine sources. In the case of the South Atlantic, the research team hypothesizes that atmospheric transport and deposition is at least as important. The proposed research will compare different BC determination procedures for deep sea sediments, thereby improving our understanding of the different constituents of the BC cycle. Similarly, organic marker molecules are often used for source apportionment. This study will explore if this still holds true for deep sea sediment samples, as preliminary data found discrepancies arising from molecular marker analysis and isotopic analysis. Lastly, accounting for soot BC in deep sea sediments will also aid in identifying more of the uncharacterized sedimentary OC . Broader Impacts: The results of this work are expected to aid atmospheric and earth system science modelers in refining their atmospheric and oceanic transport models for BC, including its relation to global climate change. The project will enhance infrastructure for research and education by establishing research collaboration between URI and international partners at the University of Bremen, the MPI for Meteorology, Hamburg, and the University of Tuebingen.

该奖项是根据2009年美国复苏和再投资法案（公法111-5）资助的。在这项研究中，罗德岛大学的研究人员将试图确定南大西洋海洋沉积物中黑碳（BC）的来源和通量。大气中的黑碳是全球气候变化的关键驱动因素；它对全球变暖的影响仅次于二氧化碳。因此，拟议的工作对我们理解碳循环是相关和及时的，碳循环是我们预测气候及其变化能力的关键组成部分。在全球范围内，二氧化碳的主要来源是化石燃料和生物质燃烧，这在非洲和南美洲都很突出。因此，本文建议采用热、化学和岩相分离相结合的方法来解释南大西洋沉积物中存在的煤烟BC、木炭和木炭。本研究提出了三个主要假设：(1)南大西洋深海沉积物中碳灰BC占总有机碳的很大一部分，并在深海沉积物中占主导地位；(2)生物质燃烧是南大西洋深海沉积物中煤烟BC的主要来源；(3)在南大西洋，大气沉积的碳烟BC与河流输入的碳烟BC同样重要。这项研究代表了首次尝试在海洋尺度上解释BC汇。因此，它有望朝着能够实现碳源和碳汇的质量平衡迈出重要的一步。先前的研究表明，BC主要从河流源头进入海洋。以南大西洋为例，研究小组假设大气运输和沉积至少同样重要。该研究将比较深海沉积物中不同的BC测定方法，从而提高我们对BC循环不同成分的理解。同样，有机标记分子也经常被用于来源分配。这项研究将探索这是否仍然适用于深海沉积物样本，因为初步数据发现分子标记分析和同位素分析存在差异。最后，计算深海沉积物中的煤烟BC也将有助于识别更多未表征的沉积OC。更广泛的影响：这项工作的结果有望帮助大气和地球系统科学建模者改进其BC的大气和海洋运输模型，包括其与全球气候变化的关系。该项目将通过建立URI与不来梅大学、汉堡MPI气象学和图宾根大学的国际合作伙伴之间的研究合作，加强研究和教育的基础设施。