Monitoring seasonal variation and anomaly trend of daytime and nighttime land surface temperature using MODIS sensor in Shiraz, Iran

Abstract

Abstract A major environmental problem in large cities and metropolitan areas is the increase in land surface temperatures (LST) caused mainly by heat islands in these areas. The LST anomaly plays an important role in climate studies, agriculture, and water resource management. This study aimed to investigate the seasonal changes and anomaly trends of daytime and nighttime LST in the Shiraz urban area. For the period 2001-2021, the LST anomaly was studied using the Terra satellite's MODIS sensor both day and night. The results revealed that the daytime temperature was positive in all seasons, with a minimum and maximum daytime temperature of 13.15°C in winter and 27.28°C in summer. In terms of location, LST was highest during the day in the central areas and in the summer season, with a temperature range of 38.44°C to 47.27°C. At night, LST does not reach a negative value at any time of the year. With a long-term average temperature of 8.09°C, the winter season in Shiraz had the lowest annual temperature, while the summer season showed the highest at 24.74°C. The maximum Z-score of the Mann-Kendall test indicated that the anomalies increased significantly in the high altitude areas such as the northeastern and northern regions of Shiraz city, changing from 0.5°C to 2.36°C. The anomaly trend of LST in this region averaged 0.84°C with a minimum of -1.29°C.