Collaborative Research: Biological and physical controls on DMS production and emission during VOCALS

海洋-大气交换具有辐射活性的生物成因痕量气体二甲基硫化物(DMS)是大气硫酸盐气溶胶的主要来源：全球气候系统的关键要素。气候通过决定上层海洋的物理化学特征来影响这种交换，从而塑造海洋浮游生态系统和DMS的来源强度。更全面地了解海洋生态系统和气候之间的相互作用是一项令人兴奋的挑战，几乎还没有开始探索。在这项研究中，毕格罗海洋科学实验室和夏威夷大学马诺阿分校的研究人员将研究光照水平、海面温度、上升的营养物质和风对DMS的产生及其向大气排放的影响。爪子假说中的这些关键联系潜在地决定了这种物理-生物反馈是积极的还是消极的。PAR和UV的适度变化是增加还是减少DMS的产生和向大气的排放？这将在补充声乐项目的背景下进行研究，该项目研究CLAW的大气部分：二甲基硫氧化成硫酸盐气溶胶及其对云和地球S辐射收支的影响。评估这种生物反馈的大小和迹象具有重大的社会和科学意义。具体而言，这项研究将涉及东南太平洋水域的以下主题：(A)上升流对DMS产量和海气通量的生物地球化学影响在多大程度上延伸到近海；(B)较少的云量如何影响生物DMS的产量和Sw浓度；以及(C)Sw DMS浓度的空间梯度和通量控制因素(如风)如何影响DMS向大气的通量。在人声雷克斯的合成阶段，并与其他参与研究人员合作，最终目标将是确定生物反馈在控制东南太平洋辐射预算方面的意义。该项目将产生几个更广泛的影响。将支持1名博士后助理(Bigelow)和1名研究生(夏威夷)的培训。此外，Bigelow Pi将继续参与农村(当地)K-8项目，以及由岛屿研究所(罗克兰，缅因州)领导的NSF ITEST农村教育、管理和技术社区赠款管理咨询小组。夏威夷PI将在他的本科生和研究生水平的海洋学和大气化学课程中使用这些数据作为例子(用于习题集和测试题)。两名PI都将参加由雷克斯协调的声乐推广活动。

Ocean-atmosphere exchange of the radiatively active biogenic trace gas, dimethylsulfide (DMS), is a major source of atmospheric sulfate aerosols: a key element of the global climate system. Climate affects this exchange by determining the physical-chemical characteristics of the upper ocean, thus shaping the marine planktonic ecosystem and the source strength of DMS. Attaining a more complete understanding of the interactions between the marine ecosystem and climate is an exciting challenge, which has barely begun to be explored. In this study, researchers at the Bigelow Laboratory for Ocean Sciences and the University of Hawaii at Manoa will examine the impact of light levels, sea surface temperature, upwelled nutrients, and winds on the production of DMS and its emission to the atmosphere. These critical linkages in the CLAW Hypothesis potentially determine whether this physical-biological feedback will be positive or negative. Does a modest change in PAR and UV increase or decrease DMS production and emission to the atmosphere? This will be studied in the context of complementary VOCALS projects studying atmospheric portions of CLAW: the oxidation of DMS to sulfate aerosols and their impact on clouds and the Earth?s radiation budget. Evaluating the magnitude and sign of such biotic feedbacks is of major societal and scientific importance. Specifically, the research will address the following themes in the South East Pacific (SEP) waters: (a) how far does the biogeochemical impact of upwelling on DMS production and air-sea flux extend offshore, (b) how do fewer clouds affect biological DMS production and SW concentrations, and (c) How do spatial gradients of SW DMS concentration and flux-controlling factors (e.g., winds) affect DMS fluxes to the atmosphere. The ultimate goal, in the synthesis phase of VOCALS REx and in collaboration with other participating investigators, would be to determine the significance of biotic feedbacks in controlling the radiation budget of the Southeast Pacific. The project will have several broader impacts. Training of one postdoctoral associate (Bigelow) and one graduate student (Hawaii) will be supported. In addition, the Bigelow PI will continue her participation in rural (local) K-8 programs as well as in the Grant Management Advisory Panel for the NSF ITEST grant Communities for Rural Education, Stewardship, and Technology led by the Island Institute (Rockland, ME). The Hawaii PI will use this data as examples (for problem sets and test questions) in his undergraduate and graduate level oceanography and atmospheric chemistry classes. Both PIs will participate in the VOCALS REx-coordinated broader outreach activities.