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

摘要：0125306作为陆架盆地倡议的一部分，这项研究将测量北冰洋楚科奇-博福特大陆架地区选定地点的沉积反硝化速率。该地区兼性厌氧细菌的整体反硝化作用是多种因素的作用，包括下伏沉积物的氧化状态、有机质输入的时空变化、底水硝酸盐浓度、沉积生物扰动和生物灌溉的速率以及水柱过程。北冰洋宽阔大陆架上的反硝化作用目前估计占全球海洋反硝化速率的很大一部分，此外还消耗了泛北极地区无机氮收支的很大一部分。该区域的反硝化作用可能会受到全球气候变化的影响，这些影响要么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水域流入模式的改变，要么是由于海冰分布的改变导致气候驱动的生态系统结构和功能的改变。为了更好地了解这一北极陆架盆地目前氮循环的可变性，调查人员将扩大以前在该地区进行的有限数量的反硝化速率测量，并将这些测量与一些促成环境驱动因素中的一个或多个联系起来。

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.