Surface ozone climatology of South Eastern Brazil and the impact of biomass burning events

Abstract

In the austral spring, biomass fires affect a vast area of South America each year. We combined in situ ozone (O3) data, measured in the states of São Paulo and Paraná, Brazil, in the period 2014-2017, with aerosol optical depth, co-pollutants (NOx, PM2.5 and PM10) and air backtrajectories to identify sources, transport and geographical patterns in the air pollution data. We applied cluster analysis to hourly O3 data and split the investigation area of approximately 290,000 km 2 into five groups with similar features in terms of diurnal, weekly, monthly and seasonal O3 concentrations. All groups presented a peak in September and October, associated with the fire activities and enhanced photochemistry. The highest mean O3 concentrations were measured inland whilst, besides having lower concentrations, the coastal group was also associated with the smallest diurnal and seasonal variations. The latter was attributed to lower photochemical activity due to frequently occurring overcast weather situation. The mean annual regional contribution of O3 over the area was 61 g/m 3 , with large seasonal and intersite variabilities (from 35 to 84 g/m 3). The long-range transport of smoke contributed with between 23 and 41% of the total O3 during the pollution events. A pollution outbreak in September 2015 caused many-fold increases in O3, PM2.5 and PM10 across the investigation area, which exceeded the World Health Organisation recommendations. We show that the regional transport of particulates and gas due to biomass burning overlays the local emissions in already highly polluted cities. Such an effect can outweigh local measures to curb anthropogenic air pollution in cities.

COVID-19 lockdown and its impact on tropospheric NO2 concentrations over India using satellite-based data

“…In comparison to atmospheric particles, the relatively lower NO 2 reduction could be due to household emissions, including biomass burning ( Targino et al., 2013 , 2019 ; Sidhu et al., 2017 ; Chowdhury et al., 2018 ), because this remained active in India during the lockdown. Correspondingly, NO 2 has a short lifetime and a high dispersion rate in the atmosphere during the summer ( Val Martin et al., 2008 ).…”

How mobility restrictions policy and atmospheric conditions impacted air quality in the State of São Paulo during the COVID-19 outbreak

“…These aspects are relevant to have a realistic assessment of how much the mobility restrictions imposed by the COVID-19 impacted the region's air quality. Another aspect of great relevance is the long-range transport of pollutants from fires in central South America and the Amazon region ( Martins et al, 2018 ; Targino et al, 2019 ). In this sense, the automatic air quality stations were grouped according to the economic vocation of the regions where they are located, as shown in Fig.…”

“…Studies carried out during the pandemic in other regions demonstrate the impact of meteorological variables on air quality, showing that it is impossible to assess changes in pollutant concentrations in a dissociated manner ( Hörmann et al, 2020 ; Ordóñez et al, 2020 ; Petetin et al, 2020 ). Furthermore, in Brazil, an important factor that cannot be neglected are the fires outbreaks, which affect different regions of the country, changing the level of pollutant concentrations, even in large centers ( Lopes et al, 2012 ; Martins et al, 2018 ; Pereira et al, 2011 ; Targino et al, 2019 ). In MASP, favorable conditions for the dispersion of pollutants were found before (February 25 - March 23) and during the partial quarantine (March 24 - April 20), which indicates that the observed reductions in pollutants, during the first weeks of the COVID-19 outbreak, were not determined by changes in the atmospheric conditions ( Nakada and Urban, 2020 ).…”

Airborne PM2.5 and the Emergence of 10 SARS-CoV-2 Variants The Multifaceted Influence of an Airborne Pollutant on Viral Natural Selection determining SARS-CoV-2 Evolution - An Environmental Wake-up Call or an Ecological Fallacy?

“…Combustion of biomass produces increased quantities of low-lying pollution exacerbated in part, to the South Atlantic subtropical high pressure system. Transported over considerable distances from wildfires, this pollution further contributes to poor air quality and smog in Sao Paulo (Targino et al 2019).…”