Abstract
Abstract. Biogenic volatile organic compound (BVOC) emissions are one of the essential inputs for chemical transport models (CTMs), but their estimates are associated with large uncertainties, leading to significant influence on air quality modelling. This study aims to investigate the effects of using different BVOC emission models on the performance of a CTM in simulating secondary pollutants, i.e. ozone, organic, and inorganic aerosols. European air quality was simulated for the year 2011 by the regional air quality model Comprehensive Air Quality Model with Extensions (CAMx) version 6.3, using BVOC emissions calculated by two emission models: the Paul Scherrer Institute (PSI) model and the Model of Emissions of Gases and Aerosol from Nature (MEGAN) version 2.1. Comparison of isoprene and monoterpene emissions from both models showed large differences in their general amounts, as well as their spatial distribution in both summer and winter. MEGAN produced more isoprene emissions by a factor of 3 while the PSI model generated 3 times the monoterpene emissions in summer, while there was negligible difference (∼4 %) in sesquiterpene emissions associated with the two models. Despite the large differences in isoprene emissions (i.e. 3-fold), the resulting impact in predicted summertime ozone proved to be minor (<10 %; MEGAN O3 was higher than PSI O3 by ∼7 ppb). Comparisons with measurements from the European air quality database (AirBase) indicated that PSI emissions might improve the model performance at low ozone concentrations but worsen performance at high ozone levels (>60 ppb). A much larger effect of the different BVOC emissions was found for the secondary organic aerosol (SOA) concentrations. The higher monoterpene emissions (a factor of ∼3) by the PSI model led to higher SOA by ∼110 % on average in summer, compared to MEGAN, and lead to better agreement between modelled and measured organic aerosol (OA): the mean bias between modelled and measured OA at nine measurement stations using Aerodyne aerosol chemical speciation monitors (ACSMs) or Aerodyne aerosol mass spectrometers (AMSs) was reduced by 21 %–83 % at rural or remote stations. Effects on inorganic aerosols (particulate nitrate, sulfate, and ammonia) were relatively small (<15 %).
Highlights
Biogenic volatile organic compounds (BVOCs) from the terrestrial biosphere play an important role in atmospheric chemistry
European air quality in the year 2011 was simulated by the regional air quality model Comprehensive Air Quality Model with Extensions (CAMx) using two biogenic volatile organic compound (BVOC) emission models: MEGAN and Paul Scherrer Institute (PSI) model
The model results were evaluated by O3 measurements from the European air quality database (AirBase v7), as well as the aerosol measurements at nine aerosol chemical speciation monitors (ACSMs)/aerosol mass spectrometers (AMSs) stations
Summary
Biogenic volatile organic compounds (BVOCs) from the terrestrial biosphere play an important role in atmospheric chemistry. They affect production of ozone (Calfapietra et al, 2013; Curci et al, 2009) and the formation process of secondary inorganic aerosol (SIA) (Aksoyoglu et al, 2017) and are the largest source of secondary organic aerosol (SOA). Curci et al (2009) compared effects of two different biogenic emission inventories, one based on Guenther et al (1995) and one based on Steinbrecher et al (2009), on ozone in Europe for 4 years (1997, 2000, 2001, 2003). Understanding the potential influence of biogenic emissions on European air quality is of great importance, especially under the continuously reduced anthropogenic emissions since the early 1990s
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
