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In this research, the effect of two indicators OMI and RMM of Maden Julian fluctuation on the frequency of dust storms in Abadan, Ahvaz, Bostan, Bandar Mahshahr, Dezful, Ramhormoz and Masjed Soleyman located in Khuzestan province during six months (April to September) of the statistical period (1987 - 2021) was reviewed. Pearson's correlation coefficients between dust data and indicators were investigated and its results were calculated in the form of income zoning maps and the frequency percentage of each indicator for positive and negative phases. The results of the research findings indicate that there is a direct and significant relationship between the positive and negative phases of both indicators with dust, except for Dezful station in the positive phase of OMI and the negative phase of RMM and the highest correlation coefficient for Bandar Mahshahr and Dezful station is between -0.7-20.77 is in the positive phase of the RMM index. The relationship between the Madden Julian Oscillation and dust showed that between 51 and 59 percent of dust storms occurred in the negative phase of the OMI index and 40 to 49 percent in its positive phase. In the RMM index, 56 to 63 percent of dust storms occur in its negative phase and 37 to 50 percent in its positive phase. In fact, the negative phase of the RMM index has a higher percentage of dust storms than the negative phase of the OMI index. According to the results of the Monte Carlo test, the displacement of the positive and negative phases of the RMM index significantly leads to the occurrence of dust storms for most of the stations in Khuzestan province. Tracking the paths of dust entering Khuzestan province with the HYSPLIT model shows the movement of particles from Iraq, Arabia and the eastern parts of Syria towards the studied area. 

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Today, fine dust and dust storms have become one of the important issues and problems of Iran and other regions of the world. This study is conducted to identify synoptic patterns of the dust storms in Ardabil Province (Iran) and monitor the origin and pathway of its places. The studied period is 34 years (1979-2013). The data used in this work are from synoptic stations of Ardabil province and the NASA’s upper atmosphere database. To achieve the goals of the study, the Environment to Circulation, Hierarchical Clustering Methods, and HYSPLIT model were used. According to the results, three patterns of geopotential height at 500 hPa levels were identified. Pattern No. 1 and 2 are almost similar to each other and represent the occurrence of a deep trough that formed from Central Europe and extended to the middle of the Red Sea. Based on these patterns, the study area is located in the East of this trough. The third pattern represents the occurrence of cut-of-low pressure blocking over the Black Sea and adjacent areas and placement of Ardabil province in the East trough of the formed blocking. The origin of dust in patterns 1 and 2 is the Eastern regions of Iraq and West of Iran while in pattern 3 is at 500 hPa level of the central areas of Iraq and at pressure levels of 850 and 1000 hPa of the central regions of Syria.
Keywords: Dust storm, Pattern extraction, synoptic analyses, HYSPLIT model, Ardabil province

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The aim of this study was to identify the epicenter and co-occurrence factors of dust storm wave from 1 to 3 November 2017 in Kermanshah. To investigate the synoptic conditions of the causes of this phenomenon, from the European Central Center (ESMWF) mid-term weather forecast data set with a resolution of 0.125 degrees of arc including, geopotential height, omega, sea level pressure, orbital and meridional components, humidity. The Lagrangian method of HYSPLIT model was used to orient the source of dust particles. in this study, dust storm WRF-chem was simulated using a paired numerical weather forecasting model. Finally, through the processing of MODIS satellite images, its scope was determined. Examination of HYSPLIT tracking maps shows that two general paths for dust transfer to the area can be identified. 1- The northwest-southeast route, which passes through dust cores formed in the deserts of Iraq and Syria, transports dust to the western half of Iran. 2- Southwest to west of Iran and Kermanshah, which is the main source of dust on November 2 and 3, The source of the particles is Kuwait, northern Saudi Arabia and part of Iraq. The spatial distribution of the dust interpreted by the MODIS sensor images is consistent with the spatial distribution of the dust concentration simulated by the WRF-chem model.