Surface and Tropospheric Column Observations of Combustion Tracers During the 2021 Wildfire Crisis in the Central Mediterranean: Insights from the WMO/Gaw Station of Lamezia Terme in Calabria, Southern Italy

The central Mediterranean and nearby regions were affected by extreme wildfires during summer 2021. During the crisis, Türkiye, Greece, Italy and other countries faced numerous challenges ranging from the near complete destruction of landscapes to human losses, and high outputs in emissions which compromised local air quality. In the Mediterranean basin, atmospheric monitoring stations perform continuous measurements of chemical and meteorological parameters meant to track and evaluate greenhouse gas and pollutant emissions in the area. In the case of wildfires, CO (carbon monoxide) and formaldehyde (HCHO) are effective tracers and the integration of satellite data on tropospheric column densities with surface measurements can provide additional insights on the transport of air masses originating from wildfires. At the Lamezia Terme (code: LMT) World Meteorological Organization – Global Atmosphere Watch (WMO/GAW) observation site in Calabria, Southern Italy, a new multiparameter approach combining different methodologies has been used to expand the knowledge the summer 2021 crisis. A previous study focused on wildfires affecting specifically the Aspromonte massif area in Calabria itself: in this study, the integration of surface concentrations, tropospheric columns, and backtrajectories has allowed to pinpoint additional contributions from other southern Italian regions, north Africa and Greece. CO data were available for both surface and column assessments, while HCHO data were only available through satellite. In order to correlate the observed peaks with wildfire phenomena, surface BC (black carbon) was also analyzed. The analysis, which focused on July and August 2021 data, pinpointed case studies highlighting distinct sources of combustion processes during the wildfire crisis of that year. Although wildfires have certain local effects in terms of biomass loss and direct damage to both the environment and human infrastructures, their broad impact on air quality also requires monitoring via the integration of multiple methodologies and the cross-analysis of satellite and surface data.