Phytoplankton Organic Carbon and Sulfur Cycling at the Marginal Ice Edge Zone

边缘冰缘区浮游植物有机碳和硫循环

• 批准号: 9200436
• 负责人: Maria Vernet
• 金额: $ 31.87万
• 依托单位: University of California-San Diego
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1992
• 资助国家: 美国
• 起止时间: 1992-03-15 至 1996-02-29
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9200436&HistoricalAwards=false
• 关键词: Phytoplankton; Organic; Carbon; Sulfur; Cycling

Arctic phytoplankton may act as a sink for carbon dioxide (CO2) and a major producer of dimethylsulfide (DMS). Maximum effects are expected in the marginal ice zone where phytoplankton blooms extend from May to September as the ice recedes northwards. These productive waters can cover more than half the area of arctic shelf seas, such as the Barents Sea, in any one growth period. One of the main components of the phytoplankton at the marginal ice zone is Phaeocystis pouchetii which, in its colonial form, is a high producer of DMS. This species is known to excrete a high proportion of newly fixed carbon as high molecular weight polymers in order to form the colony. Later, it sinks in mass in the latter stages of the bloom when nitrate becomes limiting. Diatoms, such as Thalassiosira gravida, may dominate the bloom at the ice edge late in the summer and may also precede the P. pouchetii bloom in early spring (i.e. Chaetoceros socialis). The different patterns of dissolved organic carbon formation and cell sedimentation between P. pouchetii and diatoms need to be included in productivity models for an understanding of the production and sink of CO2 and DMS in arctic shelf areas. The objectives of this field and laboratory study, in collaboration with Norwegian scientists, are to: (1) to determine the quantitative differences between P. pouchetii and diatoms blooms in the ice edge with respect to primary production, proportion of carbon fixed that is extracellular, DMS production, and sedimentation of particulate carbon and sulfur to depth: (2) to determine which are the main environmental variables that favor each type of bloom using a 10-year time series from the Barents Sea; and (3) to estimate a 10-year time series of DMS production and CO2 uptake by combining the existing time series with carbon and sulfur budgets of the ice edge blooms. This research will provide a first approximation to the seasonal and interannual variability of the phytoplankton contribution to the carbon and sulfur cycle during the ice edge bloom in arctic shelf areas.

北极浮游植物可以充当二氧化碳（CO2）的水槽和二甲基硫化物（DMS）的主要生产国。 随着冰层向北逐渐消退，浮游植物浮游的边际冰区预计将产生最大的影响。 这些生产的水域可以在任何一个生长时期内覆盖北极货架海的一半以上。 边缘冰区的浮游植物的主要成分之一是Phaeocystis pouchetii，其殖民形式是DM的高生产商。 已知该物种将高比例的新固定碳排泄为高分子量聚合物，以形成菌落。 后来，当硝酸盐限制时，它在盛开阶段的质量中沉入质量。 硅藻（例如Thalassiosira gravida）可能在夏季晚些时候在冰上的盛开占主导地位，也可能在早春P. pouchetii Bloom（即Chaetoceros Socialis）之前占据主导地位。 生产力模型中需要包括溶解有机碳形成的不同模式以及P. pouchetii和硅藻之间的细胞沉积，以了解北极货架区域中二氧化碳和DMS的生产和下沉。 该领域和实验室研究的目标与挪威科学家合作，要：（1）确定P. pochetii和P. pouchetii和硅藻之间在冰块中相对于初级生产中的硅质膨胀的定量差异，固定的碳固定的比例，固定的碳外，DMS的产生和阳离子的变化，以确定含有颗粒的碳和硫磺的变量，以确定均具有颗粒状的碳和sulfur：（2），这些变体是有利于碳纤维和sulfur carbor和sulfur dept的：（2）。来自巴伦支海的10年时间序列； （3）通过将现有时间序列与冰边缘开花的碳和硫预算相结合，以估算DMS生产和二氧化碳吸收的10年时间序列。 这项研究将为北极架子地区的冰边绽放期间浮游植物对碳和硫循环的季节性和年际变异性提供第一个近似值。