Analysis of soil depth temperature changes in Iran according to classification of atmospheric circulation patterns

Abstract

The purpose of this study was to investigate the relationship between atmospheric circulation patterns and soil depth temperature changes in Iran. To verify the correlation between atmospheric circulation patterns and soil temperature changes in the country, ten synoptic stations in the geographical range of Iran representing different climates were selected for research and analysis of data. To extract the circulation patterns by cluster analysis using Ward linkage method, nine circular clusters were identified and extracted. Among the patterns, five patterns were identified during the cold season, two patterns during the warm period, and two patterns during the transition period. Soil temperature data were first deseasonalized and changes (increase and decrease) due to the presence of warm and cold season were removed. The results of the correlation analysis between soil temperature changes in the nine-dimensional or nonuple patterns showed that there was no significant correlation between the mentioned patterns and temperature changes in the studied stations in models No. 1 and No. 2. The results of correlation analysis also showed that there was significant correlation between circulation patterns and soil temperature changes in seven other circulation patterns. The results of correlation analysis also showed that among patterns of circulation, patterns 7, 4, and 9 had the most impact on soil temperature changes in the country.