Seasonal variation of N ₂ O flux at the water air interface and its influencing factors in the Inner Mongolia section of the Yellow River in 2023

This study collected 24 samples from 6 sampling points in Inner Mongolia in different seasons in 2023 to study and analyze the spatiotemporal variation of nitrous oxide (N2O) flux at the water air interface and its influencing factors. The research results show that the average N2O emission flux is 6.63 ± 11.86 mg·m−2·d−1, which is the overall source of N2O emissions. The main influencing factors are total phosphorus (TP) and water temperature (Tw). From a seasonal perspective, summer (July) is mainly affected by potential and temperature, autumn (September) is mainly affected by total suspended solids (TSS), and winter (November) is mainly affected by TP, which are the ‘sources’ of N2O emissions; Spring (April) is the ‘sink’ of N2O emissions. From a spatial distribution perspective, the N2O flux in Lao Niu Bay (LNW) is the highest, influenced by dissolved organic carbon (DOC); Next is Linhe (LH), which is affected by total nitrogen (TN); Next are Wuhai (WH) and Urad Front Banner (QQ); Tuo County (TX) has the lowest; Baotou (BT) takes second place and is affected by ammonia nitrogen (NH4+- N). The N2O flux of WH, QQ, and TX is not significantly correlated with environmental factors.