Methane bursts during spring thaw in the permafrost region of Northeast China

Spring thaw in permafrost regions is associated with episodic bursts in atmospheric methane concentration. In this study, these methane bursts were investigated across different permafrost types in Northeast China. MODIS data and Sentinel-5P methane observations were used to derive the thaw onset date and methane burst timing, respectively. Results showed that methane bursts exhibited distinct spatial and interannual variability. Methane burst date was delayed with increasing permafrost stability, and median burst dates occurred in early to mid-April in unstable permafrost, late April to early May in semi-stable permafrost and stable permafrost. Meanwhile, methane bursts generally occurred within 15 days after thaw onset. There was a consistent positive relationship between thaw onset date and methane burst date across all years, with regression slopes of 0.78–1.07. Notably, the median lag tended to shorten from 15 to 22 days in 2020 to 11 days in 2024, suggesting an increasingly rapid temporal response of methane bursts to spring thaw over the study period.