Nitrous oxide (N2O) is an important greenhouse gas, which is 300 times more effective per unit weight as a greenhouse gas than CO2 , affecting global climate changes. The ocean hypoxic zones are important sources of N2O, and their N2O output account for half of the net output of marine N2O. Under the background of the expansion of the ocean hypoxic zone induced by rising global temperature and seawater eutrophication, the N2O output may break a new record, accelerating the process of global warming. This article systematically summarized the source-sink processes and distributions of marine N2O and relative microbiology mechanism in various ocean hypoxic zones, including the open ocean minimum oxygen zone (OMZ), the hypoxic zone of continental shelf, estuary and coastal sea, as well as the anaerobic basin. The paper pointed out that the flux and dynamic data of N2O in coastal hypoxic zones induced by anthropogenic activities was more scarce compared with the open ocean hypoxic zones. Moreover, most studies only focused on N2O production process and neglect the consumption process, and were lack of understanding of the regulatory mechanism, which may lead to deviations in the estimation of ocean N2O revenue and expenditure contributions. The comprehensive approach of combining molecular ecology with geochemistry should be a powerful tool for exploring the source and sink, dynamic characteristic and regulation mechanism of N2O in the ocean hypoxic zone in the future.
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