An analysis of urban heat island based on the temperature inversion across the atmospheric boundary layer in Mashhad, Iran (2018–2022)

• Published in: Spatial information research (Online) 2024, 32(5), 140, pp.607-622
• Main Authors: Mansouri Daneshvar, Mohammad Reza, Khatami, Rayeheh, Ebrahimi, Majid
• Format: Article
• Language: English
• Subjects: Database Management; Earth and Environmental Science; Geographical Information Systems/Cartography; Geography; Remote Sensing/Photogrammetry; 공학일반
• ISSN: 2366-3286; 2366-3294
• DOI: 10.1007/s41324-024-00585-x

This paper aimed to investigate the inversion characteristics of Mashhad City (Iran) in different time scales during 2018–2022. Results revealed a total set of 1318 diurnal inversions out of 1826 days (264 days per year). About 46% of total events belonged to the strong or severe inversion classes. Annually, the severe class of inversion events has increased from 2018 (15% of annual events) to 2022 (32% of annual events). The mean temperature [mean height] of the base and top levels of inversions was estimated equal to 11.39 and 15.25 °C [28 m and 225 m above ground level], respectively. The correlation test revealed the significant and negative relationships between the total frequency of inversion events [inversion intensity index] and wind speed with R values from − 0.635 to -0.910 [-0.426 to -0.926] for all time scales. This strong result confirmed that the temperature inversion occurred in the study area when the wind speed was calm or very slight (without prevailing winds). Also, the intensive inversions represented an evident synoptic system of the atmosphere (i.e., indicating a broad-scale sinking motion, negative temperature, and negative zonal wind at the level 1000-hPa) associated with the local triggering of urban heat island (UHI) effect.