Investigation of inversion characteristics in atmospheric boundary layer: a case study of Tehran, Iran

Abstract

Atmospheric stability originated from temperature inversion is a main challenge in the metropolitan areas especially during the cold seasons. This study aims to investigate temperature inversion characteristics of atmospheric boundary layer in Tehran within 2010-2014. Some parameters such as height, layer thickness, air pressure and temperature difference between base and top of inversion layer were studied in order to detect radiation and subsidence inversions. The results showed that among total 1138 days with inversion events about 1015 and 123 days were classified as radiation and subsidence inversions, respectively. According to an empirical equation, daily inversion intensity was categorized from weak to severe. The most inversions occurred in summer while, the least happened in spring. However, the most severe intensity values were recorded in autumn with 58 days, while the weakest values were recorded in spring with 170 days. Height of the base level of the inversion layer in all autumn seasons is in lowest distance from Earth surface. Hence, environmental impact of the inversion events in autumn is more intense in Tehran.

Surface-based nocturnal air temperature inversions in southern Poland and their influence on PM10 and PM2.5 concentrations in Upper Silesia

“…For example, the frequency of nocturnal inversions in Athens was lower than that in Sosnowiec, reaching 44% (Katsoulis 1988). In Tehran, Iran, the annual frequency of boundary layer inversions in 2010-1014 was 62%, ranging from 54% in winter to 73% in summer (Tavousi and Abadi 2016). In the Bergen valley in Norway at night during winter in 2012/2013, SBTIs accounted for more than 60% of all measurements (Wolf et al 2014).…”

“…The boundary layer structure was also researched based on radiosonde observations (Seidel et al 2010;Wang and Wang 2014). Based on data from radiosondes, detailed studies on inversion climatology were carried out for Łeba (northern Poland) on the Baltic coast (Czarnecka et al 2019), Germany (Gutsche 1983), Prague in the Czech Republic (Stryhal et al 2017), Athens in Greece (Katsoulis 1988;Prezerakos 1998;Kassomenos and Koletsis 2005), Oman (Abdul-Wahab et al 2004), Teheran in Iran (Tavousi and Abadi 2016), China (Li et al 2019) and the Arctic (Kahl 1990;Bradley et al 1992;Serreze et al 1992;Bourne et al 2010;Malingowski et al 2014). Palarz et al (2018) investigated the climatology of SBTIs in Europe based on reanalysis.…”

Relationships between Vertical Temperature Gradients and PM10 Concentrations during Selected Weather Conditions in Upper Silesia (Southern Poland)

“…The highest probability of the longest and strongest SBI in SON (not in DJF) results from the lower wind speed and cloudiness in that season in the GZM area compared to that in DJF. In Teheran, the strongest SBI also occurs in SON [79].…”

“…The above literature overview revealed that both SBI and air pollution depend on meteorological conditions; however, a complex study of co-occurring phenomena (SBI and AQ) under the background weather conditions described by selected meteorological elements has not been studied based on long-term vertical measurements (25 years) in an urban environment. The vast majority of studies have used data from short-term experiments, ranging from several months to 5 years e.g., [77][78][79][80], or from weather stations located at the ground surface but at various altitudes e.g., [1,53,57]. Complex studies counting a set of meteorological elements and their impacts on SBI and air pollution are rare [39,56,81].…”