This study analyzes six frontal dust storms in the Middle East during the cold period (October–March), aiming to examine the atmospheric circulation patterns and force dynamics that triggered the fronts and the associated (pre- or post-frontal) dust storms. Cold troughs mostly located over Turkey, Syria and north Iraq played a major role in the front propagation at the surface, while cyclonic conditions and strong winds facilitated the dust storms. The presence of an upper-atmosphere (300 hPa) sub-tropical jet stream traversing from Egypt to Iran constitutes also a dynamic force accompanying the frontal dust storms. Moderate-Resolution Imaging Spectroradiometer (MODIS) and Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation (CALIPSO) observations are used to monitor the spatial and vertical extent of the dust storms, while model (Weather Research and Forecasting model coupled with Chemistry (WRF-Chem), Copernicus Atmospheric Monitoring Service (CAMS), Regional Climate Model-4 (RegCM4)) simulations are also analyzed. The WRF-Chem outputs were in better agreement with the MODIS observations compared to those of CAMS and RegCM4. The fronts were identified by WRF-Chem simulations via gradients in the potential temperature and sudden changes of wind direction in vertical cross-sections. Overall, the uncertainties in the simulations and the remarkable differences between the model outputs indicate that modelling of dust storms in the Middle East is really challenging due to the complex terrain, incorrect representation of the dust sources and soil/surface characteristics, and uncertainties in simulating the wind speed/direction and meteorological dynamics. Given the potential threat by dust storms, more attention should be directed to the dust model development in this region.

中文翻译：

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中东地区六次沙尘暴的大气动力学和数值模拟

这项研究分析了寒冷时期（10月至3月）在中东发生的六次额头沙尘暴，旨在研究触发前缘和相关（额前或额后）沙尘暴的大气环流模式和动力变化。主要位于土耳其，叙利亚和伊拉克北部上空的冷槽在地表锋传播方面起着重要作用，而旋风条件和强风促进了沙尘暴。从埃及流向伊朗的高大气层（300 hPa）亚热带急流也构成了伴随额尘暴的动力。中分辨率成像光谱仪（MODIS）和云气激光雷达和红外探路者卫星观测（CALIPSO）观测用于监测沙尘暴的空间和垂直范围，同时分析了模型（天气研究与天气预报模型与化学（WRF-Chem），哥白尼大气监测服务（CAMS），区域气候模型4（RegCM4））的仿真。与CAMS和RegCM4相比，WRF-Chem的输出与MODIS的观测结果更好地吻合。通过WRF-Chem模拟，通过潜在温度的梯度和垂直截面中风向的突然变化来识别锋面。总体而言，模拟中的不确定性和模型输出之间的显着差异表明，由于地形复杂，尘埃来源和土壤/表面特征的不正确表示以及模拟中的不确定性，中东沙尘暴的建模确实具有挑战性风速/方向和气象动态。