Data from: Continental margin sediments underlying the NE Pacific oxygen minimum zone are a source of nitrous oxide to the water column

This study was conducted in the NE Pacific Ocean, on the outer continental shelf and upper continental margin off south-central Vancouver Island, Canada. We collected replicate sediment cores at 200, 475 and 850 m depth. Sampling stations were chosen to cover the in situ bottom water dissolved oxygen gradient, ranging from the well-oxygenated outer shelf at 200 m to the oxygen minimum zone core at 850 m. We used a microsensor approach to measure porewater N2O and O2 vertical distributions in initial and incubated cores from each sampling location. We incubated 3 cores from each location using the collected bottom water and kept them under near-in situ dissolved O2 and temperature conditions in the ship-board cold room for 24-36 hours to reestablish steady-state conditions prior to sediment profiling and subsequent modelling. N2O production and consumption rates and O2 consumption rates were estimated from measured concentration profiles using mathematical modelling.本研究于加拿大温哥华岛中南部外陆架及陆架上部边缘的东北太平洋海域开展。我们在200米、475米及850米水深采集了多组重复沉积物岩芯。采样站位的布设覆盖了原位底层水溶解氧梯度区间，涵盖200米水深处富氧外陆架至850米水深处的氧最小值区（oxygen minimum zone）核心区域。我们采用微传感器法，对各采样站位的初始岩芯与培养岩芯，测定了孔隙水中N₂O与O₂的垂直分布特征。我们利用现场采集的底层水对每个站位的3块岩芯开展培养实验，将其置于船舱冷柜中，维持接近原位的溶解氧浓度与温度条件，培养24~36小时以重建稳态，随后开展沉积物剖面分析及后续数值建模。我们基于实测浓度剖面，结合数学模型估算了N₂O的产生、消耗速率及O₂的消耗速率。