Contribution of forest fire emissions to atmospheric pollution in Greece

Forest fires are a major contributor of atmospheric gaseous and particulate pollutants. With respect to forest fires, Greece faces one of Europe’s most severe problems during summer. To create a forest fire emissions inventory, a database which holds data for forest fires in Greece during the period 1997–2003 was established in this study and a methodology for the quantification of both gaseous and particulate matter emissions from forest fires was developed. The contribution of forest fire pollutant emissions to the total anthropogenic and natural emissions in Greece has been estimated in detail for a specific period during July 2000 when widespread forest fires occurred in the Greek mainland. The mesoscale air quality modeling system UAM-AERO was used to quantify the contribution of forest fire emissions to the air pollution levels in Greece, and it was calculated that the forest fire emissions were the largest contributors to the air pollution problem in regions tens of kilometers away from the fire source during this period. The wildfire emissions were calculated to cause an increase in the average PM10 concentration, organic aerosol mass, and gaseous concentration of several pollutants, among them CO, NOx, and NH3. An average contribution of 50% to the PM10 concentration over the region around the burnt area and downwind of the fire source (approximately 500 km) is calculated with a maximum of 80%, whereas, for CO, the average contribution was 50% during this period. The theoretical calculations were compared with in situ observations of smoke aerosols captured by a backscatter lidar system over the Greater Athens Basin as well as with surface observations of NO2 and O3 and the calculated concentrations were in better agreement with observations when forest fire emissions were included in the model calculations.