Western Arctic Shelf-Basin Interactions - SBI: Collaborative Proposal: Denitrification and Sediment Nutrient Dynamics in the Chukchi and Beaufort Seas

摘要：0125306该研究将测量在楚科奇-波弗特大陆架地区的北冰洋选定地点的沉积反硝化速率，作为陆架盆地倡议（SBI）的一部分。 在这一地区的兼性厌氧细菌的整体反硝化作用是一个功能的几个因素，包括底层沉积物的氧化状态，有机物输入的时空变化，底层水硝酸盐浓度，沉积物的生物扰动和生物灌溉以及水柱过程的速率。目前估计，沿着广北冰洋大陆架的反硝化作用是全球海洋反硝化速率的重要组成部分，另外还负责消耗泛北冰洋无机氮预算的很大一部分。这一区域的反硝化作用可能会受到全球气候变化的影响，这是由于环流模式的改变，例如通过白令海峡的高营养太平洋沃茨流入模式的改变，或者由于海冰分布的改变而导致生态系统结构和功能的气候变化。为了更好地了解目前北极陆架盆地氮循环的变化，研究人员将扩展以前在该地区进行的有限数量的反硝化速率测量，并将这些测量与一个或多个环境驱动因素联系起来。

ABSTRACTOCE: 0125306The study will measure sedimentary denitrification rates at selected sites in the Chukchi-Beaufort continental shelf regions of the Artic Ocean as part of the Shelf Basin Initiative (SBI). Overall denitrification by facultative anaerobic bacteria in this region is a function of several factors including the oxygenation state of underlying sediments, spatial and temporal variation in organic matter inputs, bottom water nitrate concentrations, and the rates of sedimentary bioturbation and bioirrigation as well as water column processes. Denitrification along the wide Artic shelves is currently estimated to be a significant portion of the global oceanic denitrification rate and additionally responsible for consuming a significant fraction of the pan-Artic inorganic nitrogen budget. Denitrification in this region will likely be subject to the impact of global climate change brought about by either altered circulation patterns, such as changing inflow patterns of high nutrient Pacific waters through the Bering Straits, or climate driven changes in ecosystem structure and function resulting from altered sea-ice distributions. In order to better understand the present variability of nitrogen cycling in this Arctic shelf basin, the investigators will extend a limited number of denitrification rate measurements previously made in the region, and relate these to one or more of a number of contributing environmental drivers.