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J. Jiang et al.
5.1 Introduction
The BVOC (biogenic volatile organic compounds) emissions have a significant influence on atmospheric reactions leading to formation of secondary pollutants such as
ozone and secondary particles in many areas, especially in summer. In many intercomparison studies, modelers share the same anthropogenic emissions, but the biogenic emissions usually differ [3], making the comparison of results from different
models difficult. Since the uncertainties in BVOC emission estimates are very high
[8, 9], it is important to know the range of variability in simulated pollutant concentrations while using different BVOC emissions. In this study, we investigated the
effects of using two different BVOC emission models on ozone as well as inorganic
and organic particles in Europe during summer and winter periods in 2011.
5.2 Methods
We simulated the European air quality in 2011 using the regional air quality model
CAMx (Comprehensive Air quality Model with extensions, v6.30, www.camx.
com) and the meteorological model WRF-ARW (Weather Research and Forecasting
Model, v3.7.1; [10]. Our model domain covered Europe with a horizontal resolution
of 0.25° × 0.125° and there were fourteen terrain-following layers. The gas-phase
mechanism was CB6r2 [5]. We used the fine/coarse option to calculate the concentrations of fine particles (PM 2.5 ) and the VBS scheme for organic aerosols. Initial and
boundary conditions were obtained from the global model MOZART [6]. Anthropogenic emissions were based on the TNO-MACC-III inventory [7]. Two different
biogenic emission models were used in this study to estimate BVOC emissions (isoprene, monoterpenes and sesquiterpenes) as well as NO emissions from soil. The
first model was the PSI-model which was first developed by Andreani-Aksoyoglu
and Keller [1] and updated later by Oderbolz et al. [8]. It calculates BVOC emissions
using temperature and photosynthetically active radiation (PAR) from WRF, land
cover data from USGS and the vegetation inventory GlobCover (http://due.esrin.esa.
int/page_globcover.php). The second model was the widely used MEGAN v2.1 [4]
that covers 147 individual compounds within 19 categories. MEGAN also used the
same meteorological data from WRF. The land use data was the Community Land
Model version 4 (CLM4) and the leaf area index (LAI) was used to simulate changes
of vegetation during the year. The ozone and organic aerosol (OA) concentrations
calculated in two simulations using PSI-model and MEGAN, respectively, were
compared with ACSM/AMS (Aerosol Chemical Speciation Monitor/Aerosol Mass
Spectrometer) measurements at 8 European sites. Modelled ozone concentrations
were compared with measurements at 537 rural AIRBASE (European Air Quality
Database v7) stations.
J. Jiang et al.
5.1 Introduction
The BVOC (biogenic volatile organic compounds) emissions have a significant influence on atmospheric reactions leading to formation of secondary pollutants such as
ozone and secondary particles in many areas, especially in summer. In many intercomparison studies, modelers share the same anthropogenic emissions, but the biogenic emissions usually differ [3], making the comparison of results from different
models difficult. Since the uncertainties in BVOC emission estimates are very high
[8, 9], it is important to know the range of variability in simulated pollutant concentrations while using different BVOC emissions. In this study, we investigated the
effects of using two different BVOC emission models on ozone as well as inorganic
and organic particles in Europe during summer and winter periods in 2011.
5.2 Methods
We simulated the European air quality in 2011 using the regional air quality model
CAMx (Comprehensive Air quality Model with extensions, v6.30, www.camx.
com) and the meteorological model WRF-ARW (Weather Research and Forecasting
Model, v3.7.1; [10]. Our model domain covered Europe with a horizontal resolution
of 0.25° × 0.125° and there were fourteen terrain-following layers. The gas-phase
mechanism was CB6r2 [5]. We used the fine/coarse option to calculate the concentrations of fine particles (PM 2.5 ) and the VBS scheme for organic aerosols. Initial and
boundary conditions were obtained from the global model MOZART [6]. Anthropogenic emissions were based on the TNO-MACC-III inventory [7]. Two different
biogenic emission models were used in this study to estimate BVOC emissions (isoprene, monoterpenes and sesquiterpenes) as well as NO emissions from soil. The
first model was the PSI-model which was first developed by Andreani-Aksoyoglu
and Keller [1] and updated later by Oderbolz et al. [8]. It calculates BVOC emissions
using temperature and photosynthetically active radiation (PAR) from WRF, land
cover data from USGS and the vegetation inventory GlobCover (http://due.esrin.esa.
int/page_globcover.php). The second model was the widely used MEGAN v2.1 [4]
that covers 147 individual compounds within 19 categories. MEGAN also used the
same meteorological data from WRF. The land use data was the Community Land
Model version 4 (CLM4) and the leaf area index (LAI) was used to simulate changes
of vegetation during the year. The ozone and organic aerosol (OA) concentrations
calculated in two simulations using PSI-model and MEGAN, respectively, were
compared with ACSM/AMS (Aerosol Chemical Speciation Monitor/Aerosol Mass
Spectrometer) measurements at 8 European sites. Modelled ozone concentrations
were compared with measurements at 537 rural AIRBASE (European Air Quality
Database v7) stations.