Modification of the chemical environment during Modification of the chemical environment during long-range transportlong-range transport
M. Auvray & I. BeyM. Auvray & I. Bey
GEOS-CHEM Meeting – April 2005
Swiss Federal Institute of Technology, Lausanne, Switzerland
Laboratoire de Modélisation de la Chimie Atmosphériquehttp://lmca.epfl.ch
Acknowledgements: C. Reeves (chemical terms), S. Turquety (biomass burning Acknowledgements: C. Reeves (chemical terms), S. Turquety (biomass burning emissions), ACSOE – EXPORT – ICARTT/ITOP teams, …emissions), ACSOE – EXPORT – ICARTT/ITOP teams, …
Scientific questions
1. How is the model capable to reproduce observed O3 production and loss rates (focus on the North Atlantic/Europe area) ?
2. To what extent long-range transport modify these chemical terms?
Perturbation of O3 chemical terms by long range transport
GEOS-CHEM version v7-01-02
Resolution 2° x 2.5°
EMEP emissions over Europe
One-year initialisation
Hemispherical Background Ozone produced from natural emissions of NOx and VOCs + CH4 + stratospheric ozone
North American contribution Ozone produced from anthropogenic emissions emitted over North America
European contribution Ozone produced from anthropogenic emissions emitted over Europe
Asian contribution Ozone produced from anthropogenic emissions emitted over Asia
Methodology
The Model
Definitions
Aircraft campaigns
European contributionAsian contributionN. American contribution
Hemispheric background
O3 budget over the ACSOE domain, April 1997
Comparison with key observed chemical species - ACSOE
ObservationsModel
N. Am. Europe
April
September
O3 (ppbv) CO (ppbv) NO (pptv) PAN (pptv) NOy (pptv)
Evaluation of O3 production and loss term with ACSOE, April 1997 - 1
GEOS-CHEM
Reeves et al.
Data from Reeves et al., JGR, 2002
Grid-box model constrained by measured in situ photolysis rate and observed concentrations of O3, H2O, CO, H2O2 and CH3OOH
NO + HO2 NO2 + OH NO + CH3O2 NO2 + CH3O O3 + OH O2 + HO2
O3 + HO2 2 O2 + OHO3 + hν 2 OHOH
GEOS-CHEM
Reeves et al.
Evaluation of individual reactions
Evaluation of O3 production and loss term with ACSOE, April 1997 - 2
Data from Reeves et al., JGR, 2002
Sensitivity of O3 chemical terms to ship emissions during ACSOE, April 1997
Simulation without ship emissions
Standard simulation
Data from Reeves et al., JGR, 2002
Comparison with key observed chemical species - EXPORT, July & August 2000
O3 budget over the EXPORT domain
European contributionAsian contribution
N. American contribution
Hemispheric background
O3 (ppbv) CO (ppbv) NO (pptv) NO2 (pptv) PAN (pptv) NOy (pptv)
ObservationsModel – EMEP
N. Am. EuropeModel – no EMEP
GEOS-CHEM
Reeves et al.
Evaluation of O3 production and loss term with EXPORT, July & August 2000
Data from Reeves et al., EXPORT-E2 Final Report, 2002
Zoom
2. Perturbation of the background environment over the North Atlantic ocean by North American plume
North American plume: boxes where CONAm > (median + st dev) CONAm
Background: boxes where CO < median CO
O3 Prod Loss [ppbv/day] O3 net Prod [ppbv/day]NAm Plume
DifferenceBackground
3. Seasonal variations of production and loss of O3 over the North Atlantic ocean
January April July October
O3 net Prod [ppbv/day]
O3 Prod Loss [ppbv/day]
NAm Plume
DifferenceBackground
Preliminary conclusion
ACSOE: O3 production is overestimated, specially < 4 km O3 loss is underestimated, specially < 3 km
Next step: Examine sensitivity of O3 production and loss rates
1. To different parameters: - relative humidity - J-value - heterogeneous reactions on aerosols
2. Using outputs from another 3D global model (MOZECH – collaboration with M. Schultz, MPI-Hamburg)
3. Use the ICARTT/ITOP data
EXPORT: O3 net production is overestimated in upper troposphere
DC8
P3
BAE 146
Falcon
O3 (ppbv) CO (ppbv) NO (pptv) NO2 (pptv) PAN (pptv) NOy (pptv)
ObservationsModel – S. Turquety Biomass burning emissions
Comparison ITOP/ICARTT obs. - GEOS-CHEM
Continuation of the ICARTT/ITOP projectFocus on long-range transport of aerosol: how does it impact Europe?Case-study: aerosol layer, seen by the DLR and by the lidar at Paris
(Courtesy: Hans Schlager)
DLR Falcon 23 July 04
HNO3 RH
O2 H2O
O2RCHO
NO
NO2
HO2
OH RO2
RO NO2
NO
hνO3
O2
Ohν
O3
O2
O
NO + HO2 NO2 + OH NO + CH3O2 NO2 + CH3O
PO3 = k1 [NO] [HO2] + k2 [NO] [CH3O2]
k1 k2
Production of O3
HO2
OH
O3
O2
hν
O1D
H2O
O3
O2
O3 + OH O2 + HO2 O3 + HO2 2 O2 + OH O3 + hν 2 OHOH
LO3 = k3 [O3] [OH] + k4 [O3] [HO2] + J [O3]
k3 k4 J
Destruction of O3
HNO3 RH
O2 H2O
O2RCHO
NO
NO2
HO2
OH RO2
RO NO2
NO
hνO3
O2
Ohν
O3
O2
O
NO + HO2 NO2 + OH NO + CH3O2 NO2 + CH3O
O3
O2
hν
O1D
H2O
O3
O2
O3 + OH O2 + HO2 O3 + HO2 2 O2 + OH O3 + hν 2 OHOH
Production and destruction of O3
Production and destruction of O3
HNO3 RH
O2 H2O
O2RCHO
HO2
OH RO2
RO NO2
NO
hνO3
O2
Ohν
O3
O2
O
NO + HO2 NO2 + OH NO + CH3O2 NO2 + CH3O
O3
O2
hν
O1D
H2O
O3
O2
O3 + OH O2 + HO2 O3 + HO2 2 O2 + OH O3 + hν 2 OHOH
CO
NOy
NO2
NO
PAN
+ NO2