The relation between the number of sunspots and fluctuation in the trend of climatic components in Iran during recent decades

Document Type: Research Paper

Author

Department of Geography, Golestan University, Gorgan

Abstract

This analysis was conducted on 31 synoptic stations in Iran. Initially, the Mann-Kendall test was administered in order to analyse the trend of alterations of these two components over time and the results suggest that 16% of the stations show significant relationship with annual precipitation (positive and negative). More stations showed significant relationships between sunspots and minimum annual temperature (74.19%), maximum annual temperature (48.38%) and mean annual temperature (67.8%). The amounts of the above correlations include all of the significant trends, whether those that show inverse significant trends or those that demonstrate direct significant trends. On further investigating the relationship between variations in the number of sunspots and temperature, 5 temporal ranges were used. This analysis was conducted on raw data (without a moving average) and also data with a moving average of 5, 8, 11 and 22 year. The general conclusion drawn from different precipitation temporal ranges of data was that a significant amplification (reduction) for Iran’s stations with a frequency coefficient of 25.16% was observed. But when this relation is reversed, the frequency coefficient turned out to be 12.92. Likewise, for different components of temperature, the inverse relation between the number of sunspots and alterations of temperature possesses a higher frequency position among the stations. This value is 15.46 % for the minimum temperature, 16.12% for the maximum and 12.89% for the annual average temperature

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