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

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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.