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

摘要：作为陆架盆地计划（SBI）的一部分，该研究将测量北冰洋楚科奇-波弗特大陆架区域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几个因素的函数，包括下垫沉积物的氧化状态、有机质输入的时空变化、底水硝酸盐浓度、沉积生物扰动速率、生物灌溉速率以及水柱过程。据目前估计，沿广阔的北极大陆架的反硝化作用占全球海洋反硝化速率的很大一部分，而且还消耗了泛北极无机氮预算的很大一部分。该地区的反硝化可能会受到全球气候变化的影响，这可能是由于环流模式的改变，例如通过白令海峡改变高营养太平洋水域的流入模式，或者由于海冰分布的改变而导致气候驱动的生态系统结构和功能的变化。为了更好地了解目前北极陆架盆地氮循环的可变性，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促成环境驱动因素联系起来。

ABSTRACTOCE: 0125275The 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.