Stronger winds increase the sand-dust storm risk in northern China

The biggest sand-dust storm from Mongolia in the past decade swept across northern China on March 15, 2021. Before this sudden outbreak, the number of sand-dust storms in northern China had been decreasing for 50 years. Wind and sand resources are the two key elements for sand-dust storms to occur. With an abrupt shift to a drier and hotter climate in the past 20 years over inner East Asia providing more sand resources and an increasing wind speed trend, the sand-dust storm in 2021 may herald the beginning of an era with more sand-dust storms. To answer whether increasing wind speed will significantly influence the sand-dust storm frequency, this study analyzed the relationship between the annual average wind speed and sand-dust storm days in northern China and Mongolia, finding that they have a high correlation (R = 0.94) in northern China and a moderate correlation (R = 0.41) in Mongolia. We further found that the wind speed during sand-dust storms also decreased, which further supports that the decrease of sand-dust storm frequency is mainly reasoned from the decrease of wind speed. Therefore, as the wind speed increases, the sandstorm frequency can increase as well, which has been seen clearly in Mongolia but may be just beginning in China.