Frequency Distribution Analysis of Land Surface Temperature (LST) over Iran Using Remote Sensing Observations from Aqua MODIS

Environmental changes such as ablation of ice and snow, drying of lakes, deforestation, desertification and urbanization may affect the thermal properties of the land surface, and hence, it affects the land surface temperature (LST). MODIS LST data, make it possible to investigate the variations in the frequency distribution of LST. In this research, 16 years of MODIS\Aqua LST data (2002-2022) have been analyzed using principal component analysis. This study shows that the frequency distribution of LST in Iran depends to a great extent on altitude and then depends on the terrain surface features. Lakes, river systems, sand dunes, deserts, woodlands, forests and metropolitan areas are among the terrain surface features that affect the frequency distribution of LST. Hence, analysis of the frequency distribution of LST may be considered as a tool for identifying the geographical boundaries of these terrain features. Additionally, it could be a robust tool for tracking the changes in the boundaries of such geographical phenomena over time. Frequency analysis of LST in Iran reveals many natural and anthropogenic environmental changes. For example, the analysis shows that the drying out of Zayanderud downstream and Urmia Lake is related to man-made changes in the upstream. The comparison of the interdecadal of LST shows that the frequency of LST has increased in some temperature categories and decreased in some other temperature categories. In general, the frequency shift of LST both during the day and at night has been toward higher temperatures.