Analysis and estimation of gaseous air pollutant emissions emitted into the atmosphere during Manavgat and Milas wildfire episodes using remote sensing data and ground measurements

Abstract

In this study, the concentration levels of CO, NO₂, CH₂O, SO₂, and O₃ gases emitted during the two biggest wildfire episodes observed in Manavgat and Milas, Türkiye in 2021 were analyzed and spatio-temporal gas concentrations were estimated. Using the remote sensing imagery from Sentinel-5P satellite, a daily based time-series data analysis was performed over the Google Earth Engine platform (GEEp) and the gas emission levels (mol/m²) during the wildfires were obtained. The processed time-series data has been associated with the measurements from ground-stations of Türkiye National Air Quality Monitoring Network, allowing unit conversion to gas concentration unit in μg/m³. Based on predicted gas concentrations, statistical performance measurements were calculated with actual ground-station measurements. According to the spatio-temporal gas concentrations, the highest levels of CO gas emissions were detected on July 29^th in Manavgat 5492.63 ± 325.12 μg/m³ and on August 5^th in Milas 1071.14 ± 230.41 μg/m³. During the wildfire episodes NO₂ concentration has reached to 383.52 ± 19.31 μg/m³ in Manavgat and 34.76 ± 8.20 μg/m³ in Milas. The O₃ levels during the wildfires were estimated as 5.54 ± 16.09 μg/m³ in Manavgat and 41.22 ± 2.07 μg/m³ in Milas. The average SO₂ concentration was 71.49 ± 4.2 μg/m³ in Manavgat and 165.35 ± 6.51 μg/m³ in Milas. Also, the average CH₂O concentration was estimated as 12.83 ± 5.07 μg/m³ in Manavgat and 17.91 ± 4.41 μg/m³ in Milas. R² values were between 0.67 and 0.84. Generally, IA values were higher than 0.70. The statistical results showed that our approach was reasonably successful in the prediction of the spatio-temporal wildfire gas emissions and can be applied to such scenarios.