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

北冰洋的快速变形为我们提供了一项自然实验，必须利用这一实验来揭示多种环境应激源对海洋初级生产力(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、营养物质和温度)的反应以及随之而来的气候反馈(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)量化强烈影响PP的氮循环生物步骤，以及(3)调查与营养负荷和淡水输送有关的北极/次北极连通性。要实现这些目标，将需要每年进行一次船基探险，以进行过程研究、空间调查和为自主观测站(系泊)提供服务。预计阿蒙森号每年夏天将在北极至少呆上3-4个月，以覆盖不同的时间序列地点。该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)、模拟原地条件或气候驱动扰动的实验孵化(初级生产，N循环的步骤)，并分离形成水华的浮游植物，以便随后评估它们的生长动态和对温度、养分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带着船回来，但他们必须以其他方式飞进和飞出船(将人员留在船上超过一次轮换既不富有成效，也不可取)。去阿蒙森的往返票价是每人3000美元。要求《北方补编》支持这些费用。产生的新知识将使加拿大管理者、政策制定者和行业能够更好地评估、预测和适应不断变化的冰川及其对生态系统健康和服务的影响。加拿大人获得的其他好处包括更好地了解海洋生态系统和远北大西洋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。

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.