Climate factors influencing springtime dust activities over Northern East Asia in 2021 and 2023

In the springs of 2021 and 2023, northern East Asia experienced intense dust activities resulting in significant environmental and ecological impacts. This study explores the climate factors responsible for these strong dust activities in both springs. Results show that the anomalous surface warming during the late winter and early spring and the anomalous dry surface soil moisture in the spring are the underlying surface factors contributing to the occurrence of intense dust activities in these two years. Furthermore, we find that the anomalous wave patterns over the Eurasian continent are dynamic factors driving the initiation of dust activities in these two springs. The intensified north-south pressure gradient in Gobi Desert (GD) associated with the wave patterns significantly increases near-surface wind speeds, favoring the occurrence of dust activities. The sea surface temperature (SST) anomalies in the North Atlantic and tropical eastern Pacific can significantly influence the wind speed anomalies in northern East Asia, thereby impacting dust activities. In 2021, the increase in wind speed in the GD was influenced by both the warm SST anomalies in the North Atlantic and the cold SST anomalies in the tropical eastern Pacific. Nevertheless, in 2023, the predominant influence came from the exceptionally strong warming in the North Atlantic, offsetting the opposing effect of warm SST anomalies in the tropical eastern Pacific. Sensitivity experiments confirm the important role of the SST anomalies in the North Atlantic and tropical eastern Pacific on the dust activities in GD. These findings play an insight into understanding of the mechanisms behind the recent variations in dust activities in northern East Asia.