A measurement-driven cross-sectional method to assess the dynamics and flux of dust transport

During dust storms, dust particles are transported within a few kilometers above the ground. However, the dynamics and flux of dust transport at these altitudes are not fully understood. In this study, we employed a synergistic wind-particle profiling system in southern China to gather detailed vertical data on both aerosol characteristics and atmospheric dynamics during an unusually severe dust storm that transported from northern to southern China in April 2025. A measurement-driven cross-sectional method was developed to investigate the vertical distribution characteristics of transport dynamics and southward flux of dust, and to assess total amount of dust transported across the country. An intense spring cold front, combined with high dust emissions from the Gobi Desert, drove this southward transport. During the lower-level transport period, dust was primarily transported below 1.5 km, with a maximum southward flux density of 4.9 ± 2.9 g/m² at 775 m. The higher-level transport period exhibited a bimodal flux pattern. Additionally, the west-east distribution of dust concentration followed a Gaussian distribution. The total dust flux transported to southern China during the entire event was approximately 2.48 × 105 tons. Our cross-sectional approach supports quantitative investigations of the transport dynamics of various atmospheric components above the ground.