Estimates of oceanic emissions of nitrous oxide (N₂O) are surrounded by a considerable degree of uncertainty, particularly regarding the contribution of productive shelf regions, where assessments are based on limited observations. In this paper, we have applied a coupled hydrodynamic‐biogeochemical model resolving N₂O dynamics to estimate N₂O emissions within the northwest European continental shelf. Based on 10‐year average distributions (2006–2015), dominant seasonal patterns of N₂O air‐sea exchange were identified. Within the southwest region of the shelf and deep parts of the North Sea, emissions are highest during winter. Peak emissions during late autumn are typical for the northwest part of the shelf and central North Sea, while in the western English Channel, Irish Sea and western North Sea peak outflux shifts toward early autumn. Within these regions, most N₂O production occurs below the seasonal pycnocline, and duration and intensity of stratification defines the timing and rate of its subsequent release to the atmosphere. In contrast, within the southeast North Sea and most of the coastal areas, lack of stratification allows the excess N₂O to outgas as soon as it is produced, driven by ammonium availability, resulting in peak emissions in summer. We estimate that N₂O emissions from the northwest European shelf contribute 0.02224 Tg N to the atmosphere annually, that is, between 3.3–6.8% of total emissions from European shelves and estuaries.

中文翻译：

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模拟西北欧洲大陆架上一氧化二氮排放的季节性和控制

一氧化二氮（N ₂ O）的海洋排放量估计值存在很大程度的不确定性，尤其是在生产性架子地区的贡献方面，其中的评估是基于有限的观察结果。在本文中，我们应用了解决N ₂ O动力学的水动力-生物地球化学耦合模型来估算西北欧洲大陆架内的N ₂ O排放。根据十年平均分布（2006-2015年），N _2的主要季节格局确认了海空交换。在大陆架的西南地区和北海深处，冬季的排放量最高。秋季的峰值排放在架子的西北部和北海中部是典型的，而在英吉利海峡西部，爱尔兰海和北海西部的峰值流出量则向秋季初转移。在这些区域内，大多数N ₂ O产生发生在季节性比诺可林以下，并且分层的持续时间和强度决定了其随后释放到大气中的时间和速率。相反，在北海东南部和大部分沿海地区，由于缺乏分层，因此多余的N ₂O的产生，是由于铵的可利用性，使其一生产就立即脱气，导致夏季排放达到峰值。我们估计，欧洲西北陆架的N ₂ O排放量每年向大气中贡献0.02224 Tg N，即占欧洲陆架和河口总排放量的3.3–6.8％。