资源环境科技发展态势分析平台

Wind erosion raises mineral dusts from dry and semidry lands and produces dust storms. Such dust masses have created numerous health and economic problems for the residents of southern, southwestern, and central parts of Iran. The main sources, movement, spread, and settlement of dust masses can be determined by solving the governing equations for aerosol transmission. Such information will be certainly useful in managerial decision-making. In this study, the dust event in Tehran on 20-22 February 2016 was studied using numerical model, Moderate Resolution Imaging Spectroradiometer satellite data, and data of ground-based stations. A comparison between the numerical results and in situ measurements as well as satellite data confirmed that present modeling can predict dust mass formation and its development toward Tehran. However, the values of dust concentration and aerosol optical depth were underpredicted with regard to in situ measurements and satellite data, respectively. The results indicated that a low-pressure system was formed in the central Iran on 19-20 February, which led to atmosphere instability, an increase in wind speed, and an increase in the planetary boundary layer height up to a height of 5km. On the other hand, this low-pressure system led to the transportation of dust mass created in the eastern Syria and central Iraq from the southwestern borders and cities like Ahwaz to the central parts of Iran such as Tehran. The study of the radiative forcing indicated that due to the absorption and scattering of radiation flux by aerosols, the atmosphere became stable and the height of the boundary layer decreased.