The potential impact of the eruption of huge volcanoes of the twentieth century on the temperature change of selected stations in Iran

Volcanic activity can cause climate fluctuations by disrupting the entry of sunlight. In this study, the effect of major volcanic activities in the world on temperature changes in Iran has been investigated. To achieve this, first 16 meteorological stations with long-term statistics in Iran were selected and a long-term temperature series was received from the Meteorological Organization. Then, VEI and DVI indexes were used to select major volcanoes and six major volcanoes were selected. SEA and multiple linear regression techniques were used to investigate the effect of major volcanic activity on temperature in Iran. The results showed that after major volcanic eruptions, the effects of decreasing temperature can be observed with time delays of zero, one and two years, and the greatest intensity of temperature decrease was observed in the first year after the occurrence of the volcano. Comparison of the three variables of mean temperature, minimum mean temperature and maximum mean temperature showed that volcanic activity has the greatest decreasing effect on the mean maximum temperature. The results of the study to separate the seasons also showed that in winter the intensity of the decreasing effect occurs more, but in summer the decreasing effect of volcanoes lasts longer. Finally, the findings of this study show that on average, in the year of the occurrence of major volcanoes, a decrease of -67.0 degrees Celsius, in the first year after the eruption, the rate of decrease of -1 degrees Celsius and in a two-year delay, the average decrease. Temperature -0.47 degrees Celsius has been observed. Therefore, it can be confirmed that the eruption of major volcanoes has affected the temperature of Iran and has caused a decrease in temperature in Iran.