Spatiotemporal variability of nitrous oxide emissions from the river-estuary continuum of Yangtze River

River-estuary continuums typically receive substantial nitrogen loads from densely populated catchments. However, the spatiotemporal pattern and the influencing factors of N₂O emissions from these regions remain unclear. In this study, we investigated the N₂O flux along the river-estuary continuum of the Yangtze River and identified the key factors driving N₂O emissions. The results showed consistently supersaturated dissolved N₂O concentrations in surface water and a minor N₂O source to the atmosphere with 20.5 ± 1.8 μmol/m²/d and 11.5 ± 7.4 μmol/m²/d in the wet season and dry season, respectively. Statistical analysis showed that sediment nitrate content and denitrification potential rates were the primary drivers of N₂O emissions. The ratio of dissolved organic carbon to nitrate concentration in the water column was another critical factor associated with N₂O emissions. Our results indicated that N₂O emission in the river-estuary continuum of the Yangtze River is expected to decrease by restricting nitrogen input. These findings broaden the understandings of river N₂O dynamics and provide a fresh insight into the potential for region-specific emissions reduction.