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2年的计划，以确定以前确定的机制的重要性，这些机制可能在沉积到海洋之前和之后控制大气铁的形态。将对以前收集的海洋气溶胶样本（南大西洋，2005年;赤道太平洋，2006年）在二甲基硫醚和异戊二烯氧化产物存在的情况下进行光化学实验，因为这些化合物在实验室模拟中已显示出增加铁的生物利用率。通过优化低浓度的基本化学成分的分析能力，本研究的结果将提供进一步的证据来支持或反驳浮游植物本身是反馈循环中的关键主角的假设，以操纵气溶胶颗粒中铁的形式，以实现其最佳代谢用途。沉积在海洋中的地壳气溶胶颗粒是稀有微量营养元素铁的重要来源，限制了偏远开阔海洋中浮游植物的生长。反过来，浮游植物通过占地球光合作用吸收CO2的一半以及排放气候强迫气体（如DMS和一氧化二氮（N2 O））来调节全球气候。然而，公海气溶胶铁输送的系统学以及控制浮游植物铁生物利用率的化学仍然不明确，因此禁止对浮游植物如何影响全球气候进行任何定量分析。这项工作将由本科生和硕士进行。利用现有的和新的仪器，在中央华盛顿大学（CWU）的学生，其中后者将显着提高PI的实验室的能力，调查铁在大气中，海洋的背景。参与这项研究的学生将在现场和实验室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，为当前和未来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，包括全球变暖及其反馈机制的调节，将是本研究计划的一个组成部分。