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

Additional slides

Emissions in GEOS-CHEM – NOx in July

Basic inventory EMEP inventory

1998-2000

Emissions in GEOS-CHEM – CO in July

Basic inventory EMEP inventory

1998-2000

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

Evaluation of O3: a case study – ACSOE, 14th of September 1997

Auvray and Bey, 2005

DC8

P3

BAE 146

Falcon

Location of the ICARTT/ITOP campaigns