691 / 2024-09-19 08:38:09
The role Arctic Ocean play in global N2O budget
nitrous oxide,Arctic Ocean
Session 3 - The nitrogen cycle towards a sustainable ocean: from microbes to global biogeochemistry
Abstract Accepted
Contribution of N2O by the Arctic Ocean to global N2O budget was once neglected since it was covered by sea ice, which acts as a barrier to inhibit the exchange of N2O between the ocean and the atmosphere. With progressing of global warming, fast retreat of sea ice expose more surface water area of the Arctic Ocean to atmosphere, probably enhance the air sea exchange of N2O. Taking advantage of the Chinese National Arctic Research Expeditions and MOSAiC expeditions, together with data from other studies, the distribution pattern of N2O in the Arctic Ocean were studied, the result shows that: the continental shelves of the Chukchi Sea, Siberian Sea and Arctic Northwest Passage are generally act as source of N2O; whereas in the open ocean, the West Arctic Ocean is influenced by the Pacific water inflow from the Bering Strait, carrying the relative old and N2O enrich water, into the Arctic Ocean. However, being suppressed by stratification, this region does not show obvious source or sink characteristics; whereas in the Eastern Arctic Ocean, the Northward intruding water mass shows characteristics of N2O undersaturation since decreasing of water temperature increase its N2O solubility. However, there are also study suggested that oxygenated denitrification may be a possible mechanism to lead to this N2O undersaturation. In a word, the Arctic open water may act as a weak sink as whole for N2O, whereas the continental shelves may act as a source. Further studies are needed to address their mechanism and to predict the future tend of this N2O source and sink characteristics.