Investigating the Contribution of Biogenic Emissions to the Formation of Secondary Pollutants in Portugal
This work aims to quantify the contribution of biogenic emissions to air quality levels of secondary pollutants in distinct areas of a study region taking into account the relevance of different processes, such as transport, deposition, and chemistry. In this sense the air quality model CAMx, with its source apportionment and process analysis tools, has been applied to Portugal, aiming to assess ozone (O3) and secondary organic aerosol (SOA) levels during a summer month for three biogenic emission scenarios, which were defined considering the variability of emission factors. Results for secondary gases and particulate pollutants have been explored in terms of source and process contributions. The quantitative analysis showed that biogenic emissions contribute up to 90 % of SOA predictions. The uncertainty in isoprene emission factors may affect the concentration of SOA by ±30 % in average; however, because the O3 production is NOx limited at the studied areas biogenic emissions scenarios did not affect O3 concentration levels, which varied only ±1 % in average.
KeywordsEmission Factor Source Apportionment Reference Scenario Secondary Organic Aerosol Chemical Transport Model
The Portuguese Foundation for Science and Technology (FCT) is acknowledged for the financial support of the project EMOSAT (PTDC/CTE-ATM/103253/2008, FCOMP-01-0124-FEDER-009305), post doc grants of J. Ferreira (SFRH/BPD/40620/2007) and H. Martins (SFRH/BPD/66874/2009).
- 2.ENVIRON (2011) User’s guide to the comprehensive air quality model with extensions (CAMx) version 5.40 (September, 2011). http://www.camx.com