氧化亚氮（N2O）是引起全球变暖的主要温室气体之一，是破坏大气臭氧的重要痕量气体。研究表明海洋排放N2O量约占全球来源的1/4。然而，北冰洋由于长年的海冰覆盖被认为对海洋来源N2O的贡献可以忽略。近年来，全球变暖已引起了夏季北极海冰快速融化的明显季节性变化。根据我们在北极首次观测到季节性融冰过程显示出的海洋N2O不饱和现象，本研究提出假设：北冰洋季节性的融冰过程将是导致西北冰洋表层海水不饱和现象的主要驱动机制并可由此推动西北冰洋向N2O汇的新格局转化。本研究的实施将通过参加中国“雪龙”号破冰船的北冰洋航次，采用自主研发的N2O走航观测系统，集成稳定同位素分析技术，引进走航水同位素测量等高新技术，对西北冰洋海区进行观测，应用端元混合、湍流扩散等模式对假设进行验证，分析快速融冰情境下的西北冰洋N2O源汇格局，同时结合遥感反演等技术手段评估该情景下西北冰洋在全球N2O收支中的贡献。

N2O is one of the most important ozone depleting green house gases. Ocean is significant source, which contributes about 1/4 of the global N2O budget. However, the contribution of Arctic Ocean to global N2O budget is neglected due to sea ice covering its surface. Fast retreat of sea ice during summer in the Arctic Ocean is a sign of global warming which are concerned recently. We observed N2O undersaturation in the Western Arctic Ocean in during the sea ice melting process. A hypothesis is put forward: sea ice melting is the driven mechanism that leads to this N2O undersaturation phenomenon in the Western Arctic Ocean, and will turn the Arctic Ocean into a N2O sink. This study will take advantage of the “R/V Xuelong” to study the N2O in Western Arctic Ocean, utilizing self develop N2O underway observation system, isotopic analysis system, and the 18O isotope system, coupling with the endmember model, eddy diffusion model to test the hypothesis, to reveal the impact of fast sea ice melting on N2O source-sink characteristics, meanwhile using the data obtained from remote sensing technique to evaluate contribution of Western Arctic Ocean to the global oceanic N2O budget.