Characteristics and impacts of dust events under the background of Northeast China Cold Vortex (NCCV)

The characteristics and potential influence of dust events under the background of Northeast China Cold Vortex (NCCV) have rarely been investigated. Based on meteorological observational data and ERA5 reanalysis data from 2015 to 2023, we examined the spatiotemporal and environmental characteristics of dust events under NCCV and non-NCCV conditions and explored the potential impacts of the NCCV on dust events. The results indicate that dust days in Northeast China exhibited a trend of first decreasing and then increasing during the study period, and severe dust events mainly occurred in central Inner Mongolia, a key dust source region in China. Dust days associated with the NCCV accounted for 32.7% of the total dust days, and their station-frequency ratio reached 43.7%. Dust events were predominantly concentrated in the southwest quadrant of the NCCV periphery (60.1%), mostly within a range of 1.0–2.6 times the NCCV radius. This distribution pattern can be attributed to the strong baroclinity often related to the low-level shear lines and dry ambient conditions in this region. Moreover, strong downward momentum transfer and weakly stable stratification within the planetary boundary layer under NCCV conditions also facilitated the formation of dust events. This study reveals the important impacts of the NCCV on dust events, thereby providing a scientific basis for further understanding the formation mechanisms of such events.