The new open Flexible Emission Inventory for Greece and the Greater Athens Area (FEI-GREGAA): Account of pollutant sources and their importance from 2006 to 2012

• The new open flexible emission inventory for Greece and Athens (FEI-GREGAA) from 2006 to 2012 was constructed.
• FEI-GREGAA can be updated with available data, can be used for the study of emission scenarios and emission factors.
• National emissions of CO, NOx, SO2, VOCs-NMVOCs have dropped from 2006 to 2012, except PM following the European trends.
• The main anthropogenic activities affecting the air quality of Athens are road transport, navigation and small combustion.
• The economic crisis has lead to the slowing down of industrial activity and intensive biomass burning for heating.

Photochemical and particulate pollution problems persist in Athens as they do in various European cities, despite measures taken. Although, for many cities, organized and updated pollutant emissions databases exist, as well as infrastructure for the support of policy implementation, this is not the case for Greece and Athens. So far abstract efforts to create inventories from temporal and spatial annual low resolution data have not lead to the creation of a useful database. The objective of this study was to construct an emission inventory in order to examine the emission trends in Greece and the Greater Athens Area for the period 2006–2012 on a spatial scale of 6 × 6 km2 and 2 × 2 km2, respectively and on a temporal scale of 1 h. Emissions were calculated from stationary combustion sources, transportation (road, navigation and aviation), agriculture and industry obtained from official national and European sources. Moreover, new emission factors were calculated for road transport and aviation. The final database named F.E.I. – GREGAA (Flexible Emission Inventory for GREece and the GAA) is open-structured so as to receive data updates, new pollutants, various emission scenarios and/or different emission factors and be transformed for any grid spacing. Its main purpose is to be used in applications with photochemical models to contribute to the investigation on the type of sources and activities that lead to the configuration of air quality. Results showed a decreasing trend in CO, NOx and VOCs-NMVOCs emissions and an increasing trend from 2011 onwards in PM10 emissions. Road transport and small combustion contribute most to CO emissions, road transport and navigation to NOx and small combustion and industries to PM10. The onset of the economic crisis can be seen from the reduction of emissions from industry and the increase of biomass burning for heating purposes.