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: 2012
• 资助国家: 加拿大
• 起止时间: 2012-01-01 至 2013-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=515078
• 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.

北极海域的快速蜕变为我们提供了一个必须利用的自然实验，以揭示多种环境压力因素对海洋初级生产（PP）和生物地球化学通量的影响。PP对自然和人为强迫（冰盖、光照、养分和温度）的响应以及随后对气候的反馈（如温室气体的释放或捕获）存在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)研究北极/亚北极在养分负荷和淡水输送方面的连通性。要实现这些目标，需要每年进行一次船上考察，以进行过程研究、空间调查和服务自主观测站（系泊）。阿蒙森号预计每年夏天将在北极停留至少3-4个月，以覆盖不同的时间序列地点。这个计划要求不同的学生，研究人员和我经常反复飞往北极，进行核心测量（营养物质，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，并分离开花形成的浮游植物，以便随后评估它们的生长动态和对温度，营养供应和光照制度的耐受性。虽然人们最初可以在qu忧郁市登船，或者在野外季节结束时带着船回来，但他们必须乘飞机进出船（将人员留在船上连续超过一轮轮换是既不高效也不可取的）。到阿蒙森号往返一次的费用是每人3000美元。请北方补编支助这些费用。由此产生的新知识应使加拿大的管理人员、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逃逸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大西洋沿岸之间的关键联系，以及培训下一代极地海洋学家。