The impact of COVID-19 lockdowns on surface urban heat island changes and air-quality improvements across 21 major cities in the Middle East.

Autor: El Kenawy AM; Department of Geography, Sultan Qaboos University, Al Khoud, Muscat, Oman; Department of Geography, Mansoura University, Mansoura, 35516, Egypt. Electronic address: kenawy@mans.edu.eg., Lopez-Moreno JI; Instituto Pirenaico de Ecología, Campus de Aula Dei, Avda. Montañana, 50059, Zaragoza, Spain., McCabe MF; Division of Biological and Environmental Sciences and Engineering, King Abdullah University of Science and Technology, Thuwal, Saudi Arabia., Domínguez-Castro F; Aragonese Agency for Research and Development Researcher (ARAID), Department of Geography, University of Zaragoza, Zaragoza, Spain., Peña-Angulo D; Instituto Pirenaico de Ecología, Campus de Aula Dei, Avda. Montañana, 50059, Zaragoza, Spain., Gaber IM; GIS specialist, Department of Geography, South Valley University, Qena branch, Qena, Egypt., Alqasemi AS; Geography and Urban Sustainability, College of Humanities & Social Science, UAEU, Al-Ain, United Arab Emirates., Al Kindi KM; Department of Geography, Sultan Qaboos University, Al Khoud, Muscat, Oman., Al-Awadhi T; Department of Geography, Sultan Qaboos University, Al Khoud, Muscat, Oman., Hereher ME; Department of Geography, Sultan Qaboos University, Al Khoud, Muscat, Oman; Department of Environmental Sciences, Faculty of Science, Damietta University, New Damietta, Egypt., Robaa SM; Department of Astronomy, Space Science and Meteorology, Faculty of Science, Cairo University, 12613, Egypt., Al Nasiri N; Department of Geography, Sultan Qaboos University, Al Khoud, Muscat, Oman., Vicente-Serrano SM; Instituto Pirenaico de Ecología, Campus de Aula Dei, Avda. Montañana, 50059, Zaragoza, Spain.
Jazyk: angličtina
Zdroj: Environmental pollution (Barking, Essex : 1987) [Environ Pollut] 2021 Nov 01; Vol. 288, pp. 117802. Date of Electronic Publication: 2021 Jul 16.
DOI: 10.1016/j.envpol.2021.117802
Abstrakt: This study investigates changes in air quality conditions during the restricted COVID-19 lockdown period in 2020 across 21 metropolitan areas in the Middle East and how these relate to surface urban heat island (SUHI) characteristics. Based on satellite observations of atmospheric gases from Sentinel-5, results indicate significant reductions in the levels of atmospheric pollutants, particularly nitrogen dioxide (NO 2 ), sulfur dioxide (SO 2 ), and carbon monoxide (CO). Air quality improved significantly during the middle phases of the lockdown (April and May), especially in small metropolitan cities like Amman, Beirut, and Jeddah, while it was less significant in "mega" cities like Cairo, Tehran, and Istanbul. For example, the concentrations of NO 2 in Amman, Beirut, and Jeddah decreased by -56.6%, -43.4%, and -32.3%, respectively, during April 2020, compared to April 2019. Rather, there was a small decrease in NO 2 levels in megacities like Tehran (-0.9%) and Cairo (-3.1%). Notably, during the lockdown period, there was a decrease in the mean intensity of nighttime SUHI, while the mean intensity of daytime SUHI experienced either an increase or a slight decrease across these locations. Together with the Gulf metropolitans (e.g. Kuwait, Dubai, and Muscat), the megacities (e.g. Tehran, Ankara, and Istanbul) exhibited anomalous increases in the intensity of daytime SUHI, which may exceed 2 °C. Statistical relationships were established to explore the association between changes in the mean intensity and the hotspot area in each metropolitan location during the lockdown. The findings indicate that the mean intensity of SUHI and the spatial extension of hotspot areas within each metropolitan had a statistically significant negative relationship, with Pearson's r values generally exceeding - 0.55, especially for daytime SUHI. This negative dependency was evident for both daytime and nighttime SUHI during all months of the lockdown. Our findings demonstrate that the decrease in primary pollutant levels during the lockdown contributed to the decrease in the intensity of nighttime SUHIs in the Middle East, especially in April and May. Changes in the characteristics of SUHIs during the lockdown period should be interpreted in the context of long-term climate change, rather than just the consequence of restrictive measures. This is simply because short-term air quality improvements were insufficient to generate meaningful changes in the region's urban climate.
(Copyright © 2021 Elsevier Ltd. All rights reserved.)
Databáze: MEDLINE
Externí odkaz: