Nitrogen cycling and physical forcing of primary production in the Arctic Ocean

北冰洋初级生产的氮循环和物理强迫

• 批准号: 331401-2011
• 负责人: Tremblay, JeanÉric
• 金额: $ 1.09万
• 依托单位: Université Laval
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Northern Research Supplement
• 财政年份: 2014
• 资助国家: 加拿大
• 起止时间: 2014-01-01 至 2015-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=549257
• 关键词: Nitrogen; cycling; physical; forcing; primary

The rapid metamorphosis of Arctic seas hands us a natural experiment that must be tapped to unravel the effects of multiple environmental stressors on marine primary production (PP) and biogeochemical fluxes. The response of PP to natural and anthropogenic forcing (ice cover, light, nutrients & temperature) and the ensuing feedbacks on climate (e.g. release or capture of greenhouse gases) are subject to large uncertainties and debate. Research objectives for the next 5 years are to (1) elucidate the physical drivers of PP, (2) quantify biological steps of the nitrogen cycle that strongly affect PP, and (3) investigate Arctic/sub-Arctic connectivity with respect to nutrient loading and freshwater deliveries. Meeting these objectives will require annual, ship-based expeditions to perform process studies, spatial surveys and service autonomous observatories (moorings). The Amundsen is expected to spend at least 3-4 months in the Arctic each summer to cover the various time-series locations. This plan requires that different students, research staff and myself fly to the Arctic, often repeatedly, to perform core measurements (nutrients, chlorophyll), experimental incubations (primary production, steps of the N cycle) that simulate in situ conditions or climate-driven perturbations, and isolate bloom-forming phytoplankton for subsequent assessments of their growth dynamics and tolerances to temperature, nutrient supply and light regimes. While people can initially board the ship in Québec city or come back with it at the end of the field season, they must otherwise be flown in and out of the ship (It is neither productive nor desirable to leave personnel on the ship for more than a rotation in a row). The cost of one round trip to the Amundsen is $3000 per person. The Northern supplement is requested to support these costs. The new knowledge generated should empower Canadian managers, policy makers and industry with better means to evaluate, anticipate and adapt to the changing icescape and its impacts on ecosystem health and services. Other benefits to Canadians include a better grasp of marine ecosystems and crucial linkages between the far north and the coastal Atlantic Ocean, as well as training of the next generation of polar oceanographers.

北极海洋的快速变态为我们提供了一个自然实验，必须利用这个实验来揭示多种环境压力对海洋初级生产力（PP）和海洋地球化学通量的影响。PP对自然和人为强迫（冰盖，光照，营养和温度）的响应以及随后对气候的反馈（例如温室气体的释放或捕获）受到很大的不确定性和争议。未来5年的研究目标是（1）阐明PP的物理驱动因素，（2）量化氮循环中强烈影响PP的生物步骤，（3）调查北极/亚北极地区营养负荷和淡水输送的连通性。实现这些目标将需要每年进行船基考察，以进行过程研究、空间调查和服务自主观测站（系泊设备）。阿蒙森号预计每年夏天在北极至少停留3-4个月，以覆盖不同的时间序列位置。该计划要求不同的学生，研究人员和我自己飞往北极，经常重复，进行核心测量（营养素，叶绿素），实验孵化（初级生产，N循环的步骤），模拟原位条件或气候驱动的扰动，并隔离形成水华的浮游植物，用于随后评估其生长动力学和对温度，营养供应和光照制度的耐受性。虽然人们最初可以在魁北克市登船，或者在野外季节结束时回来，但他们必须乘坐飞机进出船只（将人员留在船上超过一排轮换既没有生产力，也不可取）。往返阿蒙森的费用是每人3000美元。要求提供北方补充款以支付这些费用。所产生的新知识应使加拿大管理人员、决策者和工业界能够更好地评估、预测和适应不断变化的冰盖及其对生态系统健康和服务的影响。对加拿大人的其他好处包括更好地掌握海洋生态系统和远北与沿海大西洋之间的重要联系，以及培训下一代极地海洋学家。