Analysis of the emission inventories and model-ready emission datasets of Europe and North America for phase 2 of the AQMEII project

This paper highlights the development of the emission inventories and emission processing for Europe (EU) and North America (NA) in the second phase of the Air Quality Model Evaluation International Initiative (AQMEII) project. The main purpose of the second phase of the AQMEII project is to understand the importance of coupled meteorological-chemical models in our understanding of the feedback of chemistry on the meteorology. A second purpose of the second phase of the AQMEII project is to explore the differences between EU and NA in a dynamic evaluation of two modeling years (2006 and 2010). The first phase of AQMEII also considered the modeling year 2006. Comparing the two AQMEII phases, for the EU domain, there were substantial decreases in CO (−19%), NH3 (−11%), and SO2 (−12%) emissions between the phase 2 and phase 1 emissions used for 2006. For the NA domain, there were decreases in CO (−10%), non-methane hydrocarbons (−5%), PM2.5 (−8%), PM10 (−18%), SO2 (−12%), with an increase of 4% in NOx. For the 2010 modeling year, 2009 emissions were used as a proxy for 2010 emissions in the EU domain. Between 2006 and 2009, considerable emission reductions were achieved for 17 EU countries, Norway and Switzerland as well as EU-Non-Member States, for all emitted species aside from NH3, which remained almost stable. Non-EU countries showed little change in emissions levels, though this may be a result of poor data quality. Shipping emissions decreased for PM and SO2 due to Sulfur Emission Control Areas on the North Sea and the Baltic Sea, while increasing for other species. Overall for the EU domain between 2006 and 2009, estimated NOx emissions decreased by 10%, SO2 by 18%, CO by 12%, PM2.5 by 5%, PM10 by 6%, NMVOC by 11%, and NH3 by 1%. Between the 2006 and 2010 modeling years, estimated US NOx emissions decreased by 17%, SO2 by 29%, CO by 21%, PM2.5 by 12%, PM10 by 7%, NMHC by 4% and NH3 by 2% while Canadian and Mexican emissions were assumed to remain constant. These changes in US emissions, however, only reflect changes in sectors for which we had year-specific information. In terms of natural emissions, climatic differences between 2006 and 2010 caused the European emissions of isoprene to peak earlier in the year 2006 than in 2010, and overall achieved higher levels in 2010. Biogenic emissions in North America increased in the east and decreased in the west between 2006 and 2010, due to regional temperature differences between the years from natural variation in solar radiation reaching the ground.