RUI: Do Dimethyl Sulfide (DMS) and Isoprene Control Iron Bioavailability in Marine Aerosols?

RUI：二甲硫醚 (DMS) 和异戊二烯能否控制海洋气溶胶中铁的生物利用度？

• 批准号: 0839851
• 负责人: Anne Johansen
• 金额: $ 13.55万
• 依托单位: Central Washington University
• 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: 2009-01-01 至 2012-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0839851&HistoricalAwards=false
• 关键词: RUI; Do; Dimethyl; Sulfide; DMS

The Principal Investigator (PI) plans a 2-year program to determine the significance of previously identified mechanisms that may control atmospheric iron speciation before and after deposition into the ocean. Photochemical experiments will be carried out on previously collected marine aerosol samples (South Atlantic Ocean, 2005; Equatorial Pacific Ocean, 2006) in the presence of dimethyl sulfide (DMS) and isoprene oxidation products, as these compounds have been shown to increase iron bioavailability in laboratory simulations. By optimizing analytical capabilities for low concentrations of essential chemical constituents, results from this study will provide further evidence to support or refute the hypothesis that phytoplankton themselves are key protagonists in a feedback cycle to manipulate the form of iron in aerosol particles for their optimal metabolic use. Crustal aerosol particles deposited at sea constitute a significant source of scarce micronutrient iron that limits phytoplankton growth in remote open oceans. Phytoplankton, in turn, modulate global climate by accounting for half the earth's photosynthetic absorption of CO2, as well as by emission of climate forcing gases, such as DMS and nitrous oxide (N2O). The systematics of open-ocean aerosol iron delivery as well as the chemistry that controls iron bioavailability to phytoplankton, however, remains ill defined thus prohibiting any quantitative analysis of how phytoplankton affect global climate. The work will be carried out by undergraduate and M.S. students at Central Washington University (CWU) with existing and new instrumentation, the latter of which will significantly increase the capacity of the PI's lab to investigate iron in the atmosphere-ocean context. Students involved in this research will obtain valuable hands-on experience in the field and the laboratory, and will interact with scientists from diverse research areas and countries, preparing them for the intricate nature of present and future scientific challenges. Outreach activities specifically designed for K-12 students that include global warming and its regulation by feedback mechanisms will be an integral part of this research program.

首席研究员（PI）计划进行一项为期两年的计划，以确定可能控制沉积到海洋之前和之后可能控制大气铁物种形成的机制的重要性。光化学实验将在先前收集的海洋气溶胶样品上进行（南大西洋，2005年；赤道太平洋，2006年），在存在二甲基硫化物（DMS）和异戊二烯氧化产物的情况下，因为这些化合物已显示出这些化合物的增加实验室模拟。通过优化低浓度必需化学成分的分析能力，这项研究的结果将提供进一步的证据，以支持或反驳浮游植物本身是反馈周期中的关键主角，以操纵气溶胶颗粒中的铁的形式，以实现其最佳代谢使用。沉积在海上的地壳气溶胶颗粒构成了稀有的微量营养铁的重要来源，该铁限制了偏远开放海洋中浮游植物的生长。反过来，浮游植物通过考虑地球的光合作用吸收CO2的一半以及通过排放气候强迫气体（例如DMS和一二氮（N2O））来调节全球气候。然而，开放海洋气溶胶铁输送的系统学以及控制浮游植物的铁生物利用度的化学物质仍未定义，因此禁止对浮游植物如何影响全球气候的任何定量分析。这项工作将由本科生和硕士华盛顿中央大学（CWU）的学生现有和新仪器，后者将大大提高PI实验室在大气环境中调查铁的能力。参与这项研究的学生将在该领域和实验室中获得宝贵的实践经验，并将与来自不同研究领域和国家的科学家进行互动，为他们做好准备，以为当前和未来的科学挑战的复杂性做好准备。专门为K-12学生设计的外展活动，包括全球变暖及其通过反馈机制的监管将是该研究计划不可或缺的一部分。