在“西北暖湿化”的背景下，甘肃省沙尘天气呈现出显著的区域性特征，东风型沙尘天气的形成机制及传输特征研究相对缺乏。本文基于常规气象观测资料、ERA5再分析资料及卫星遥感资料，并利用GDAS气象数据驱动 HYSPLIT后向轨迹模式进行模拟，对比分析了甘肃省春季三次区域性东风型沙尘天气的气候背景、环流形势、热动力物理量特征及传输特征。研究表明：（1）东风型沙尘气候背景与西风型沙尘无显著差异；扬沙发生前气温较历史同期偏高约2 ℃，沙尘暴偏高4~6 ℃，且降水距平百分率较历史同期偏少五成及以上的地区更易出现沙尘天气。（2）与西风型沙尘“西高东低”环流形势及锋区动量下传机制不同，东风型沙尘的形成与 500 hPa 高空槽偏北、地面“北高南低”（冷高压与南疆或青海东部热低压配合）的形势密切相关，冷锋位置偏北，系统东移时冷锋底部掠过甘肃北部，受冷锋后部及冷高压底部偏东大风影响，从而引发沙尘。（3）在热动力物理量特征方面，东风型沙尘与 850 hPa 上小于-4×10-5 K·s-1的冷平流、700 hPa以下大于 0. 4 Pa·s-1的正垂直速度区及中低层大于 100 m2·s-2的正水平螺旋度区有较好的对应关系，与前人所得西风型沙尘天气对应负垂直速度区、负水平螺旋度区的研究成果存在差异。（4）沙源传输方面，东风型沙尘以外源输送为主，其中扬沙天气的远距离沙源贡献大于周边沙源，沙尘暴天气则主要依赖本地荒漠及附近沙漠（如巴丹吉林沙漠、腾格里沙漠）的起沙。

Against the backdrop of the ongoing“warm-wet transition”in Northwest China，dust events in Gansu Province have exhibited distinct regional characteristics. However，the formation mechanisms and transport pat‐ terns specific to easterly dust events remain inadequately studied. This study presents a comparative analysis of three representative spring easterly dust events in Gansu，integrating conventional meteorological observations， ERA5 reanalysis data，satellite remote sensing products，and HYSPLIT backward trajectory modeling driven by GDAS meteorological fields. We systematically examined the climatic preconditions，synoptic circulations，ther‐ modynamic and dynamic parameters，and transport characteristics. The principal findings are as follows： （1）The climatic preconditions for easterly dust events show no significant divergence from those of west-events. Prior to blowing dust events，near-surface temperatures were approximately 2 ℃ above the multi-year climato‐ logical mean，whereas preceding dust storms，anomalies reached 4~6 ℃. Regions with a precipitation deficit of 50% or lower relative to the historical mean were particularly prone to dust activation.（2）In contrast to the typi‐ cal“west-high，east-low”pressure pattern and frontal subsidence mechanism associated with west-events，east‐ erly dust events are governed by a northward-displaced 500 hPa trough and a surface“north-high，south-low” pressure configuration. ，resulting from the interaction between a cold anticyclone and a thermal low situated over southern Xinjiang or eastern Qinghai. As the system propagates eastward，the anomalously positioned cold front sweeps across northern Gansu，inducing dust outbreaks driven by easterly gales behind the cold front and along the high-pressure periphery.（3）Thermodynamic and Dynamic Features，easterly dust events are character‐ ized by strong cold air advection at 850 hPa（exceeding -4×10-5 K·s-1），positive vertical velocity greater than 0. 4 Pa·s-1 below 700 hPa，and positive horizontal helicity values surpassing 100 m2·s-2 in the middle and lower tropo‐ sphere. These signatures stand in clear contrast to those of westerly dust events，which are typically associated with negative vertical velocity and negative horizontal helicity.（4）In terms of dust sources and transport，easter‐ ly dust events are predominantly driven by external transport. During blowing dust events，remote sources con‐ tribute more significantly than proximal ones. Conversely，dust storms are mainly fueled by local deserts and ad‐ jacent arid regions，such as the Badain Jaran Desert and the Tengger Desert.