Changing Concentrations of Methyl Halides, Nonmethane Hydrocarbons, Organic Sulfur Species, and Alkyl Nitrates in Response to Iron Fertilization during SOFeX

浮游植物和其他微生物在海洋中生产和消耗挥发性有机碳(VOC)物种，包括甲基卤化物、非甲烷烃(NMHC)、烷基硝酸盐和二甲基硫化物(DMS)，对平流层臭氧和全球气候产生影响。在铁(Fe)的富集实验中，首次从表层海水和低层大气中采集了几种VOCs。南大洋铁实验(SOFEX)是在2002年1月至2月期间进行的，研究人员包括Revelle、Melville和北极星号考察船。为了观察铁肥对南大洋两个高营养、低叶绿素(HNLC)区海洋生物和固碳程度的影响，进行了一系列的化学、物理和生物测量。以前的铁浓缩实验表明，初级生产力受到某些HNLC区微量铁的限制。在SOFEX期间，两个地区被施肥，一个在南极极锋的北部，另一个在南极极锋的南部。大约四分之一的海洋表层水是HNLC，可能是铁有限的。这一地区的大部分位于南大洋，这使得该地区有望通过铁肥封存额外的海洋碳来减缓全球变暖。到目前为止，新墨西哥州矿业与技术研究所的研究人员已经完成了来自SOFEX的420个海水样本的VOC分析。在该项目的支持下，他们将完成剩余98%的分析，以便2700个单独色谱图上代表每种化合物的每个峰都可以进行肉眼检查，归一化到标准，并校正平衡仪中的不平衡。美国和其他国家政府正在寻求缓解全球变暖的解决方案。一些建议涉及气候工程，如铁肥。审慎规定，在进行任何大规模的海洋铁肥之前，必须评估其对海洋生产与气候有关的化合物(如挥发性有机化合物)的影响。SOFEX实地研究的VOC结果将更好地向政策制定者和社会通报海洋生物圈和大气之间的耦合。为了更充分地了解拟议的大规模铁肥/碳封存的气候后果，这方面的知识是必不可少的。

ABSTRACTOCE-0327198Marine production and consumption of volatile organic carbon (VOC) species, including methyl halides, nonmethane hydrocarbons (NMHCs), alkyl nitrates, and dimethyl sulfide (DMS), by phytoplankton and other microorganisms have an impact on stratospheric ozone and global climate. Several VOCs were sampled from surface ocean water and the lower atmosphere for the first time during an iron (Fe) enrichment experiment. The Southern Ocean Iron Experiment (SOFeX) was conducted between January-February 2002, and involved the research vessels Revelle, Melville, and Polar Star. An extensive suite of chemical, physical, and biological measurements were made in order to observe the effects of iron fertilization on marine organisms and the extent of carbon sequestration in two high nutrient, low chlorophyll (HNLC) regions in the Southern Ocean. Previous iron enrichment experiments indicate that primary productivity is limited by trace amounts of iron in certain HNLC regions. During SOFeX, two areas were fertilized, one north of the Antarctic Polar Front and the other south of the front. Roughly one quarter of the ocean.s surface waters are HNLC and may be iron limited. Much of this area is in the Southern Ocean, making this region promising for reducing global warming by sequestering additional oceanic carbon by iron fertilization.To date, researchers at the New Mexico Institute of Mining and Technology have completed VOC analyses of 420 seawater samples from SOFeX. With support from this project, they will complete the remaining 98% of the analysis, so that each peak representing each compound on 2700 individual chromatograms can be visually checked, normalized to the standards, and corrected for disequilibria in the equilibrator. The U.S. and other governments are seeking solutions to mitigate global warming. Some proposals involve climate engineering such as iron fertilization. Prudence dictates that before any large-scale oceanic iron fertilization takes place, its impact on the marine production of climatically relevant compounds such as VOCs must be assessed. VOC results from the SOFeX field study will better inform policy makers and society on the coupling between the marine biosphere and the atmosphere. This knowledge is imperative in order to more fully understand the climatic ramifications of proposed large-scale iron fertilization/carbon sequestration.