University of Isfahan Geography and Environmental Planning 2008-5362 36 3 2025 09 23 Identifying the Synoptic Patterns Generating Dust Storms in the Ardabil Plain and Their Local Origin Identifying the Synoptic Patterns Generating Dust Storms in the Ardabil Plain and Their Local Origin 157 184 29976 10.22108/gep.2025.143518.1691 FA Bromand Salahi Professor, Department of Physical Geography, Faculty of Social Sciences, University of Mohaghegh Ardabili, Ardabil, Iran Mahmoud Behrouzi Ph.D. in Climatology, Marine Science Institute, Kish International Campus, University of Tehran, Tehran, Iran. Mahnaz Saber Postdoctoral Researcher of Climatology, Department of Physical Geography, Faculty of Social Sciences, University of Mohaghegh Ardabili, Ardabil, Iran Journal Article 2024 11 27 Abstract This study analyzed wind direction and speed data from 2000 to 2018 to identify the high winds responsible for dust events in the Ardabil Plain. To uncover the atmospheric patterns leading to dust formation, sea level pressure maps were constructed for dusty days and dust trajectories were tracked using the HYSPLIT model. The atmospheric Dust Column Mass Density (DCMD) and Aerosol Optical Depth (AOD) were employed to determine dust column concentration in the Ardabil Plain. The findings highlighted the significant influence of surface pressure systems, which contributed to dust storms by inducing instability in the region. The analysis indicated that local sources heavily influenced the frequency of summer dust storms. Tracking dust particles and analyzing synoptic patterns demonstrated that dust predominantly entered the Ardabil Plain from Iraq and Syria, as well as border areas between Iran and Iraq. The substantial pressure gradient generated by the arrival of unstable systems exacerbated local gusts, resulting in the formation of extensive dust masses in the Ardabil Plain. Notably, the maximum dust column density and optical depth recorded in July reached 0.43 kg/m² and 0.5, respectively. Keywords: AOD Index, Ardabil Plain, Dust, HYSPLIT model, Sea Level Pressure. Introduction Dust storms are a significant environmental hazard in arid and semi-arid regions, particularly during the warmer months of late spring and early summer. These storms have far-reaching consequences for public health, natural resources, economy, and agriculture. Various factors contribute to dust generation, including changes in wind intensity driven by pressure gradients, Coriolis force, poor vegetation cover, drought, conflicts, soil texture and composition, channelized winds, and synoptic patterns associated with strong winds. The interplay between climate change and human activities, including settlement patterns, has exacerbated soil degradation, wind erosion, desertification, and deterioration of soil properties, thereby intensifying dust storms. In Ardabil, industrial and mining activities have adversely affected the photosynthesis cycle, disrupted road traffic, and negatively impacted human and livestock health, placing additional strain on the healthcare system and incurring significant costs. Consequently, this study aimed to identify and analyze the factors contributing to dust formation and the atmospheric patterns responsible for dust events during warmer months in the Ardabil Plain. Materials & Methods This research utilized a combination of synoptic, statistical, satellite, and modeling approaches. To analyze dust occurrence patterns during warm months over a 19-year period (2000-2018), data were extracted and examined through an environmental lens focused on circulation. The HYSPLIT model was employed to track dust pathways in the region. The principal component reduction method was applied to identify the dust generation patterns in the Ardabil Plain for each warm month. Factor analysis was then utilized to determine the key variables influencing atmospheric circulation patterns and dust storms. Additionally, to assess the role of local sources in the occurrence of dust storms, land use changes were analyzed using the Support Vector Machine (SVM) algorithm, along with atmospheric Dust Column Mass Density (DCMD) and Aerosol Optical Depth (AOD) derived from reanalyzed MERRA data. Finally, a stepwise multivariate linear regression model was employed to estimate atmospheric dust concentration and develop a dust model for the Ardabil Plain. Research Findings Monthly analysis of dust-generating patterns in the Ardabil Plain revealed that local sources significantly contributed to the occurrence of dust storms in the study area. While dust particle tracking and synoptic pattern investigations indicated that dust primarily entered the Ardabil Plain from Iraq, Syria, and areas along the Iran-Iraq border, the large pressure gradients and shear forces created by the intrusion of unstable systems intensified local winds in the region. In the agricultural lands east of Ardabil City—specifically, approximately 3.6 kilometers from the city center and near the southern edge of Ardabil Airport and Ardabil Industrial Park No. 2—there were areas devoid of vegetation. During the dry season, the loose surface soils in these regions became destabilized due to moisture deficiency. As strong winds intensified, soil particles were lifted from the ground and transported westward towards Ardabil City, resulting in local dust storms that adversely impacted the environmental ecosystem and human health. Additionally, Ardabil Industrial Park No. 2 situated 11 kilometers east of the city near the airport and a prominent dust source contributed to increased air pollution. The activities of factories in this industrial zone released dust particles into the atmosphere, which further elevated the concentration of air pollutants when combined with mineral dust from the dust center. Discussion of Results & Conclusion The results of monitoring land use changes in the Ardabil Plain indicated that local sources significantly contributed to the occurrence of dust storms in the region. Over the past 20 years (2000-2019), the percentage of dry surface soils—identified as the primary sources of dust—had increased, while vegetation cover had diminished. This decline in vegetation had notably contributed to the rising frequency of dust storms. Vegetation played a critical role in absorbing surface moisture and retaining it on the soil, which in turn enhanced soil stability and raised the wind shear threshold speed required to mobilize surface soil particles. Consequently, stable soil conditions helped mitigate dust storms. The findings of this study revealed a reduction in vegetation cover, which had led to decreased surface soil moisture and disrupted soil balance. This instability ultimately lowered the wind shear threshold speed, making the surface soil more susceptible to being lifted by localized gusts, resulting in airborne dust that manifested as dust storms. Moreover, the regression analysis identified the role of relative humidity in estimating atmospheric dust column concentration in the Ardabil Plain. It was demonstrated that the concentration model could effectively predict dust levels based on AOD and relative humidity variables. Abstract This study analyzed wind direction and speed data from 2000 to 2018 to identify the high winds responsible for dust events in the Ardabil Plain. To uncover the atmospheric patterns leading to dust formation, sea level pressure maps were constructed for dusty days and dust trajectories were tracked using the HYSPLIT model. The atmospheric Dust Column Mass Density (DCMD) and Aerosol Optical Depth (AOD) were employed to determine dust column concentration in the Ardabil Plain. The findings highlighted the significant influence of surface pressure systems, which contributed to dust storms by inducing instability in the region. The analysis indicated that local sources heavily influenced the frequency of summer dust storms. Tracking dust particles and analyzing synoptic patterns demonstrated that dust predominantly entered the Ardabil Plain from Iraq and Syria, as well as border areas between Iran and Iraq. The substantial pressure gradient generated by the arrival of unstable systems exacerbated local gusts, resulting in the formation of extensive dust masses in the Ardabil Plain. Notably, the maximum dust column density and optical depth recorded in July reached 0.43 kg/m² and 0.5, respectively. Keywords: AOD Index, Ardabil Plain, Dust, HYSPLIT model, Sea Level Pressure. Introduction Dust storms are a significant environmental hazard in arid and semi-arid regions, particularly during the warmer months of late spring and early summer. These storms have far-reaching consequences for public health, natural resources, economy, and agriculture. Various factors contribute to dust generation, including changes in wind intensity driven by pressure gradients, Coriolis force, poor vegetation cover, drought, conflicts, soil texture and composition, channelized winds, and synoptic patterns associated with strong winds. The interplay between climate change and human activities, including settlement patterns, has exacerbated soil degradation, wind erosion, desertification, and deterioration of soil properties, thereby intensifying dust storms. In Ardabil, industrial and mining activities have adversely affected the photosynthesis cycle, disrupted road traffic, and negatively impacted human and livestock health, placing additional strain on the healthcare system and incurring significant costs. Consequently, this study aimed to identify and analyze the factors contributing to dust formation and the atmospheric patterns responsible for dust events during warmer months in the Ardabil Plain. Materials & Methods This research utilized a combination of synoptic, statistical, satellite, and modeling approaches. To analyze dust occurrence patterns during warm months over a 19-year period (2000-2018), data were extracted and examined through an environmental lens focused on circulation. The HYSPLIT model was employed to track dust pathways in the region. The principal component reduction method was applied to identify the dust generation patterns in the Ardabil Plain for each warm month. Factor analysis was then utilized to determine the key variables influencing atmospheric circulation patterns and dust storms. Additionally, to assess the role of local sources in the occurrence of dust storms, land use changes were analyzed using the Support Vector Machine (SVM) algorithm, along with atmospheric Dust Column Mass Density (DCMD) and Aerosol Optical Depth (AOD) derived from reanalyzed MERRA data. Finally, a stepwise multivariate linear regression model was employed to estimate atmospheric dust concentration and develop a dust model for the Ardabil Plain. Research Findings Monthly analysis of dust-generating patterns in the Ardabil Plain revealed that local sources significantly contributed to the occurrence of dust storms in the study area. While dust particle tracking and synoptic pattern investigations indicated that dust primarily entered the Ardabil Plain from Iraq, Syria, and areas along the Iran-Iraq border, the large pressure gradients and shear forces created by the intrusion of unstable systems intensified local winds in the region. In the agricultural lands east of Ardabil City—specifically, approximately 3.6 kilometers from the city center and near the southern edge of Ardabil Airport and Ardabil Industrial Park No. 2—there were areas devoid of vegetation. During the dry season, the loose surface soils in these regions became destabilized due to moisture deficiency. As strong winds intensified, soil particles were lifted from the ground and transported westward towards Ardabil City, resulting in local dust storms that adversely impacted the environmental ecosystem and human health. Additionally, Ardabil Industrial Park No. 2 situated 11 kilometers east of the city near the airport and a prominent dust source contributed to increased air pollution. The activities of factories in this industrial zone released dust particles into the atmosphere, which further elevated the concentration of air pollutants when combined with mineral dust from the dust center. Discussion of Results & Conclusion The results of monitoring land use changes in the Ardabil Plain indicated that local sources significantly contributed to the occurrence of dust storms in the region. Over the past 20 years (2000-2019), the percentage of dry surface soils—identified as the primary sources of dust—had increased, while vegetation cover had diminished. This decline in vegetation had notably contributed to the rising frequency of dust storms. Vegetation played a critical role in absorbing surface moisture and retaining it on the soil, which in turn enhanced soil stability and raised the wind shear threshold speed required to mobilize surface soil particles. Consequently, stable soil conditions helped mitigate dust storms. The findings of this study revealed a reduction in vegetation cover, which had led to decreased surface soil moisture and disrupted soil balance. This instability ultimately lowered the wind shear threshold speed, making the surface soil more susceptible to being lifted by localized gusts, resulting in airborne dust that manifested as dust storms. Moreover, the regression analysis identified the role of relative humidity in estimating atmospheric dust column concentration in the Ardabil Plain. It was demonstrated that the concentration model could effectively predict dust levels based on AOD and relative humidity variables.

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