Ocean–atmosphere gas exchange in the Arctic Ocean is sensitive to global warming because the decrease of sea‐ice covered area enhances the exchange. Melting sea ice affects the vertical transport of dissolved gases. Few reports of Arctic Ocean studies have described observations of dissolved N₂O or temporal variation of sea‐to‐atmosphere N₂O flux. Therefore, production mechanisms of this greenhouse gas and the stratospheric ozone depleting gas remain unclear. We measured dissolved N₂O and its isotopic signatures in the western Arctic shelf region of the Chukchi Sea and surrounding areas during September in 2014 and 2015. In the Chukchi Sea shelf, the N₂O concentration was slightly higher than the value expected under sea–air equilibrium in the surface water. It increased with depth to 23 nmol kg⁻¹ in 2014, although it showed a vertically homogeneous distribution in 2015. Isotopocule ratios of N₂O, which include ¹⁵N‐site preference in the N₂O molecule as well as elemental N and O isotope ratios, indicate that N₂O in the Chukchi Sea shelf is a mixture of N₂O produced in the bottom water and that of atmospheric origin. The isotopic signature of excess N₂O (δ¹⁵N^bulk = −3.6‰ to −1.4‰, δ¹⁸O = 61.5‰–63.0‰, SP = 38.7‰–49.0‰) suggests that it is produced by archeal or bacterial nitrification and that it is partly reduced by denitrification. Although further quantitative observations are necessary, the results confirmed that the western Arctic Ocean can act as a source of N₂O to the atmosphere when sea‐ice cover retreats and the pycnocline is weakened.

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一氧化二氮在北冰洋西部的分布及产生机理

北冰洋的海洋-大气气体交换对全球变暖敏感，因为海冰覆盖面积的减少促进了交换。海冰融化会影响溶解气体的垂直传输。很少有关于北冰洋研究的报告描述了溶解的N ₂ O或海洋到大气中N ₂ O通量随时间变化的观测结果。因此，这种温室气体和平流层臭氧消耗气体的产生机理仍然不清楚。我们测量了2014年和2015年9月在楚科奇海西部北极大陆架及其周围地区的溶解N ₂ O及其同位素特征。在楚科奇海大陆架，N ₂O的浓度略高于地表水中海气平衡下的预期值。它在2014年随深度增加而增加到23 nmol kg ^-1，尽管在2015年显示出垂直均匀的分布。N ₂ O的等容比，其中N ₂ O分子中的^15个N位点优先以及元素N和O同位素比率，表明ñ ₂楚科奇陆架O为N的混合物₂中的底部的水产生的O和，大气来源的。过量的N-的同位素签名₂ O（δ ¹⁵ Ñ^散装 = -3.6‰至-1.4‰，δ ¹⁸ O = 61.5‰-63.0‰，SP  = 38.7‰–49.0‰）表明它是由古细菌或细菌硝化作用产生的，并且通过反硝化作用而部分还原。尽管有必要进行进一步的定量观测，但结果证实，北冰洋可以在海冰覆盖撤退和比浓可可碱减弱时作为大气中N ₂ O的来源。