Akademik Veri Yönetim Sistemi
Air Quality Conference 2020 - Science and Application, Thessaloniki, Yunanistan, 18 - 22 Mayıs 2020, ss.157
Summary
A big wildfire happened in Izmir the summer of 2019 and a large forest area was destroyed. In addition to its deforestation impacts, this forest fire caused air pollution due to combustion of natural vegetation. This study aims to model the atmospheric transport of smoke released from this fire. For this purpose, a long-range atmospheric dispersion model, FLEXPART, was used. The new ECMWF dataset - ERA-5 was used as the meteorological input. The area influenced from the fire was detected from satellite data for defining the source term of the model. The analysis of satellite images also demonstrated that atmospheric transport of the smoke from the wildfire travelled towards south-west direction and effected mostly the Greek islands in the Aegean Sea. The model results were compared with data from air quality monitoring stations in Greece and in Turkey to assess the performance of the model. Introduction Wildfires cause various environmental problems such as air pollution, carbon releases and soil erosion. Pollutants that originate from forest fires are mostly smoke, NO2 and CO, which influence air quality along the flow path of the event in the atmosphere. These parameters are dispersed, transported and transformed with various atmospheric mechanisms. A wildfire in Izmir, Turkey happened in August 2019 and destroyed more than 5000 ha of forest. The fire was one of the biggest wildfires of Turkey in recent years. Satellite images demonstrated that smokes from the fire moved predominantly towards south-western direction towards the Aegean Sea and Greece, which was opposite to the city centre. Thus, the air pollution effects of the fire did not mostly influence the metropolitan centre of the City of Izmir but rather effected sparsely populated areas of the coastline and the Greek Islands. Based on this premise, this study focussed on predicting the air pollution impacts of this wildfire and demonstrate the influence of the source term on the simulated results using atmospheric dispersion modeling.
Methodology and Results
A long-ranged atmospheric dispersion model, FLEXPART, was used to simulate the atmospheric dispersion of pollutants released from Izmir Wildfire in 2019. FLEXPART is a commonly used Lagrangian particle dispersion model for the transport of atmospheric pollutants. It is also used to simulate the pollutants originating from forest fires. NO2 and CO are selected as the two characteristic species to investigate the impact of the wildfire. Release rates of NO2 and CO were defined from satellite data assisted emission factors available from the literature. Further, the newly released high resolution ERA5 dataset of ECMWF was used as meteorological input. Alternative source term definitions were made to better characterize the emissions released from the fire. The simulation results were then compared with air quality monitoring data along the downwind direction of the fire. The results revealed a fairly long-ranged transport of the contaminants as wet deposition mechanism was not available during the time of the fire.
Conclusions
The simulation of air pollutants originating from forest fires provides
valuable information on the extend and magnitude of the contamination
within short and long ranged vicinity of the event. Comparative
simulations also reveal the influence of the source terms on the
dispersion and deposition patterns of air pollutants along the downwind
direction of the fire.