University of Sistan and Baluchestan Journal of Natural Environmental Hazards 2676-4377 15 48 2026 06 22 Synoptic Examination of Thunderstorm-Inducing Atmospheric Patterns and Their Temporal Association with Sunspot Activity across Three Recent Climatic Cycles (1986–2018) in Southwestern Iran Synoptic Examination of Thunderstorm-Inducing Atmospheric Patterns and Their Temporal Association with Sunspot Activity across Three Recent Climatic Cycles (1986–2018) in Southwestern Iran 143 166 9590 10.22111/jneh.2025.51935.2113 FA Hassan Lashkari Professor of Climatology, Department of Physical Geography, Faculty of Earth Sciences, University of Shahid Beheshti, Tehran, Iran 0000-0002-6007-7275 Mohammad Naji PhD Candidate in Climatology, Department of Physical Geography, Faculty of Earth Sciences, University of Shahid Beheshti, Tehran, Iran Zainab Mohammadi Postdoctoral Synoptic climatology. Department of Physical Geography, Faculty of Earth Sciences, Shahid Beheshti University, Tehran, Iran Alireza Fadaei Bash Master of Science in Climatology, Department of Physical Geography, Faculty of Earth Sciences, University of Shahid Beheshti, Tehran, Iran Journal Article 2025 05 06 Thunderstorms, due to their dynamic and thermodynamic characteristics, can both replenish water resources and cause substantial infrastructural and human losses. This study aims to identify the synoptic patterns influencing thunderstorms in southwestern Iran, where convection is the dominant precipitation mechanism. Given that the statistical period under investigation coincides with the three most recent solar cycles, special attention was paid to variations in thunderstorm occurrence across different phases of each cycle, as well as inter-cycle differences. In this regard, the frequency of thunderstorms during the last three solar cycles and their relationship with sunspot activity were examined, and 178 events were analyzed using factor analysis and qualitative interpretation of synoptic charts. The results indicate that thunderstorm frequency undergoes significant fluctuations during solar cycles, with the changes being more pronounced in years corresponding to peak sunspot activity. For instance, in 1990, despite recording 2,296 sunspots, the number of documented thunderstorms in the region dropped to 24 events. During these periods, combined Sudan–Mediterranean systems had the greatest influence on thunderstorm development, whereas independent Sudanese, Mediterranean, and monsoonal systems played a more limited role. In the combined Sudan–Mediterranean pattern, due to the merging of ridges from the African and migratory anticyclones, the Sudan low-pressure system shifts further eastward, in contrast to the general pattern in which it travels eastward from the western Arabian Peninsula. In this pattern, after passing over the southern Red Sea via the Bab-el-Mandeb Strait, it enters the Arabian Peninsula. When the low-pressure core is positioned between Riyadh and the southern Persian Gulf, thunderstorms intensify due to substantial moisture advection from the southern seas. At mid-tropospheric levels, the Mediterranean trough exhibits a marked southward extension, and a cut-off low with a strong southward displacement settles over southern Iraq. Thunderstorms, due to their dynamic and thermodynamic characteristics, can both replenish water resources and cause substantial infrastructural and human losses. This study aims to identify the synoptic patterns influencing thunderstorms in southwestern Iran, where convection is the dominant precipitation mechanism. Given that the statistical period under investigation coincides with the three most recent solar cycles, special attention was paid to variations in thunderstorm occurrence across different phases of each cycle, as well as inter-cycle differences. In this regard, the frequency of thunderstorms during the last three solar cycles and their relationship with sunspot activity were examined, and 178 events were analyzed using factor analysis and qualitative interpretation of synoptic charts. The results indicate that thunderstorm frequency undergoes significant fluctuations during solar cycles, with the changes being more pronounced in years corresponding to peak sunspot activity. For instance, in 1990, despite recording 2,296 sunspots, the number of documented thunderstorms in the region dropped to 24 events. During these periods, combined Sudan–Mediterranean systems had the greatest influence on thunderstorm development, whereas independent Sudanese, Mediterranean, and monsoonal systems played a more limited role. In the combined Sudan–Mediterranean pattern, due to the merging of ridges from the African and migratory anticyclones, the Sudan low-pressure system shifts further eastward, in contrast to the general pattern in which it travels eastward from the western Arabian Peninsula. In this pattern, after passing over the southern Red Sea via the Bab-el-Mandeb Strait, it enters the Arabian Peninsula. When the low-pressure core is positioned between Riyadh and the southern Persian Gulf, thunderstorms intensify due to substantial moisture advection from the southern seas. At mid-tropospheric levels, the Mediterranean trough exhibits a marked southward extension, and a cut-off low with a strong southward displacement settles over southern Iraq. https://jneh.usb.ac.ir/article_9590_7d83f37c03a97a00d491210f393d2762.pdf