1. CHIMERE - Volatility Basis Set approach
18/05/10
Modeling of Organic Aerosol during the MEGAPOLI Summer Campaign in the Paris Region
CHIMERE - Volatility Basis Set approach
Q.J.Zhang (1)*, M.Beekmann (1), L. Poulain (2), A. Held (2), A. Wiedensohler (2), H. Herrmann (2), K. Kamilli (2), P. de Carlo (3), M. Crippa (3), R. Chirico (3), M. Heringa (3), Claudia Mohr (3), A. Prevot (3), U. Baltensperger (3), E. Freney (4), A. Schwarzenboeck (4), K. Sellegri (4), J.M. Pichon (4), L. Gomes (5), B. Bessagnet (6), S. Pandis (7), A. Hodzic(8)‏
(1) Laboratoire Interuniversitaire des Systèmes Atmosphériques (LISA), Université Paris Est et 7, CNRS, Créteil, France
(2) Institute for Troposphärenforschung, Leipzig, Germany,
(3) Paul Scherrer Institut, Villingen, Switzerland,
(4) Laboratoire de Météorologie Physique, Clermont-Ferrand, France
(5) Centre National de Recherche Météorologique, Toulouse, France
(6) Institut National de l'EnviRonnement industriel et des rISques, Verneuil en Halatte, France
(7) Foundation for Research and Technology, Hellas, University of Patras, Greece
(8) National Center for Atmospheric Research, USA.
* Also Aria technologies
2010/05/03
EGU, Vienna
Modeling of OA during MEGAPOLI Summer Campaign in Paris
Modeling of OA during MEGAPOLI Summer Campaign in Paris 1 1

2. 18/05/10
Context & Objective
SOA (Secondary Organic Aerosol): under-estimated in Chemistry Transport Models
Volkamer et al., GRL, 2006
Comparison Model / Measurement, 05/ /2007 LHVP , (urban MEGAPOLI site)
Observed SOA (J. Sciare, LSCE)‏
Simulated SOA (classic)‏
Simulated anthropogenic SOA (classic)‏
MEGAPOLI Paris Campaign: Quantify primary and secondary sources of organic aerosols, in urban and in plume
Objective: Improve simulation of SOA in CHIMERE (regional CTM)‏
Volatility Basis Set approach (VBS) )‏
Robinson et al., 2007
Lane et al. 2008
Compare with MEGAPOLI measurements
Modeling of OA during MEGAPOLI Summer Campaign in Paris

3. SOA scheme in CHIMERE Classic scheme in CHIMERE
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SOA scheme in CHIMERE
Classic scheme in CHIMERE
OH, O3, NO3
α∑SVOC (Surrogated Semi-volatile
VOC species with distinct volatilities)‏
VOC precursors
(Pun et Seigneur,2006, Bessagnet et al. 2008)‏
Phase transfer
Aerosol
VBS « Volatility Basis-Set » approach
VOC precursors
n ∑ SVOC with defined volatility bins OH
(Robinson et al., 2007, Lane et al. 2008, Murphy and Pandis. 2009)‏
Modeling of OA during MEGAPOLI Summer Campaign in Paris

4. VBS approach main features
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VBS approach main features
Classic POA emission
partitioning of POA (SVOC) emissions
additional IVOC emissions
Normalized emission factor with respect to classic POA emission
Chemical aging
Robinson et al., 2007,
Murphy et Pandis. 2009
∆Hv (kJ mol-1)‏
C* (µg m-3) at 298K
Saturation concentration
Semivolatile-SOA (S-SOA)‏
Modeling of OA during MEGAPOLI Summer Campaign in Paris
Modeling of OA during MEGAPOLI Summer Campaign in Paris 4 4

5. Model configuration CHIMERE Gocart/LMDz GFS/MM5 domain Resolution
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Model configuration
Gocart/LMDz
Meteorology
GFS/MM5
domain Resolution
CONT °× 0.5°
GN km ×9km
CHIMERE
Gas phase mechanism, 50 species,120 reactions
MELCHIOR2
Inorganic mechanism
(Nenes et al., 1998)‏
ISORROPIA
Two-product method /
VBS approach
SOA Scheme
EMEP
Anthropogenic
MEGAN
Biogenic
Emissions
Modeling of OA during MEGAPOLI Summer Campaign in Paris
Modeling of OA during MEGAPOLI Summer Campaign in Paris 5 5

6. Simulations with classic scheme (POA non-volatile)‏
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Simulations with classic scheme (POA non-volatile)‏
Simulations with VBS
Total SOA=Oxygenated OA
Partitioning of POA emissions (SVOC) + additional IVOC
Lumped VOC according to SAPRC
 4 volatility bins
Biogenic SOA (BSOA)‏
VBS
Classic
Semivolatile-SOA
Anthropogenic SOA
Chemical aging
(Lane et al. 2008)‏
(Robinson et al., 2007, Murphy and Pandis. 2009)‏
(Pun and Seigneur, 2006;
Bessagnet al. 2008)‏
Modeling of OA during MEGAPOLI Summer Campaign in Paris

7. AMS measurements Aerodyne aerosol Mass spectrometer (AMS)‏
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AMS measurements
Paris
Aerodyne aerosol Mass spectrometer (AMS)‏
 Organic Aerosol (OA)‏
LHVP: by IFT (urban site)‏
Preliminary simplified PMF (Positive Matrix) Factorization (Poor man’s PMF)‏
 Hydrocarbon-like Organic Aerosol (HOA)‏
 Biomass Burning Organic Aerosol (BBOA)‏
HOA+BBOA  Primary Organic Aerosol (POA)‏
 Oxygenated Organic Aerosol (OOA)‏
OOA  S-SOA+ASOA+BSOA
SIRTA: upwind of Paris agglomeration, by PSI (suburban site)
Flight: by LaMP
OA –LaMP (µg/m3)‏
Modeling of OA during MEGAPOLI Summer Campaign in Paris

8. Simulation results (LHVP-Urban site) vs. ground based AMS measurements
18/05/10
Paris
Simulation results (LHVP-Urban site)
vs. ground based AMS measurements
HOA/BBOA AMS Poor man’s PMF
POA Model-Classic
HOA Model-VBS
µg/m3
In VBS, POA SVOC+IVOC gas phase  reduce POA (aerosol)‏
OOA AMS Poor man’s PMF
SOA Model -Classic
OOA Model -VBS
µg/m3
Continental
Local
Modeling of OA during MEGAPOLI Summer Campaign in Paris

9. OA (LHVP-Urban site) Continental
18/05/10
OA (LHVP-Urban site)
Continental
Classic  over-estimate peaks, close at background concentration
µg/m3
VBS  close at peaks, underestimate background concentration
µg/m3
S-SOA_VBS
S-SOA+BSOA
POA+BSOA
Modeling of OA during MEGAPOLI Summer Campaign in Paris

10. Simulation results (SIRTA-Suburban site)
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Paris
Simulation results (SIRTA-Suburban site)
vs. ground based AMS measurements
OA AMS
OA Model -Classic
OA Model -VBS 20
µg/m3 16
Upwind  underestimated 12 8 4
July 01
July 02
July 03
July 04
July 05
July 06
July 07
July 08
July 09
July 10
July 11
July 12
July 13
July 14
July 15
July 16
July 17
July 18
July 19
July 20
July 21
July 22
Downwind
µg/m3
S-SOA_VBS
Mostly BSOA
Continental
Modeling of OA during MEGAPOLI Summer Campaign in Paris

11. Regional influence on OOA plume
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Regional influence on OOA plume
Anthropogenic
Biogenic
Local
Modeling of OA during MEGAPOLI Summer Campaign in Paris

12. Background concentration
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Local formation of OA vs. measurements on flight
Flight 32
Measurement
µg/m3
100KM
Measurement OA
Ox=O3+NO2
µg/m3
ppb
Model VBS
µg/m3
Background concentration
Model-VBS
Modeling of OA during MEGAPOLI Summer Campaign in Paris

13. 18/05/10
Conclusion
The “Volatility Basis Set” VBS approach has been implemented into a regional CTM (CHIMERE) and evaluated with measurements from the MEGAPOLI Paris summer campaign
Urban / suburban sites
The VBS approach avoids an overestimation of urban HOA
OOA peaks with strong continental influx, and a local peak with strong simulated anthropogenic aerosol are better simulated by VBS
=> important contribution from S-SOA vs. ASOA
Underestimation of OOA peaks with simulated BSOA origin,
underestimation of background concentrations.
Plume evolution (for one flight with strong OA formation in plume):
VBS under-estimates background OA levels;
slope of OA / Ox plot is OK within a factor of two
OUTLOOK :
Sensitivity tests under way (yields, chemical aging speed, POA emissions and volatility)
Redo evaluation with full data set , including winter campaign
Modeling of OA during MEGAPOLI Summer Campaign in Paris
Modeling of OA during MEGAPOLI Summer Campaign in Paris 13 13

14. 18/05/10
Acknowledgement
The research leading to these results has received funding from the European Community's Seventh Framework Programme FP/ MEGAPOLI under grant agreement n° The MEGAPOLI campaign has received additional support by French ANR and LEFE/CHAT programs, and by the Ile de France SEPPE program.
IFT, PSI and LaMP teams are thanked for providing AMS measurement data.
Modeling of OA during MEGAPOLI Summer Campaign in Paris