The GEOS-CHEM Simulation of Trace Gases over China

Li ZHANG and Hong LIAO

Institute of Atmospheric PhysicsChinese Academy of Sciences

April 24, 2008

Global Chemical Transport ModelGlobal Chemical Transport ModelGEOS-ChemGEOS-Chem

Trace GasesTrace GasesNOx, SO2, CO, O3, etc.NOx, SO2, CO, O3, etc.

Concentrations and DistributionsConcentrations and Distributionsover Chinaover China

SimulatesSimulates

InvestigateInvestigate

Contents

The GEOS-Chem Global Chemical Transport ModelThe GEOS-Chem Global Chemical Transport Model

GEOSAssimilatedMet Fields

Gas-phase Chemistry

O3-NOx-CO-CH4-NMHC

Tropospheric Aerosols

Gas-phase species

Heterogeneous reactions

http://www-as.harvard.edu/chemistry/trop/geos/

Sulfate/nitrate/ammoniumBC/POA/SOA

Sea saltMineral dust

Stratospheric Ozone input

Anthropogenic

Biogenic

Anthropogenic

Nature

Temperature

Temperature

Wind, etc.

Wind, etc.

Alternation of actinic flux

Abbreviation Met Field Type Color

G3 CH GEOS–3 China Nested Grid — 1 x 1 resolution  

G3 NA GEOS–3 North America Nested Grid — 1 x 1 resolution  

G3 2x25 GEOS–3 Global Grid — 2 x 2.5 resolution  

G3 4x5 GEOS–3 Global Grid — 4 x 5 resolution  

G4 raw GEOS–4 Global Grid — 1 x 1.25 (native) resolution  

G4 2x25 GEOS–4 Global Grid — 2 x 2.5 resolution  

G4 4x5 GEOS–4 Global Grid — 4 x 5 resolution  

G5 CH GEOS–5 China Nested Grid — 0.5 x 0.667 resolution  

G5 NA GEOS–5 North America Nested Grid — 0.5 x 0.667 resolution

 

G5 2x25 GEOS–5 Global Grid — 2 x 2.5 resolution  

G5 4x5 GEOS–5 Global Grid — 4 x 5 resolution  

Data period: 1985-2008Data period: 1985-2008

GEOS Met Data

GEOS-3 Met fields

GEOS-3 Met fields

Simulation of Ozone (O3)

The GEOS-Chem model has a very detailed simulation of gas-phase chemistry, accounting for the formation of O3 from NOx and non-methane hydrocarbon (VOCs).

Species Present-Day

2000

NOx, Tg N yr-1    

   Fossil fuel combustion 20

   Biomass burning 11

   Soil (natural) 3.9

   Soil (fertilizer) 0.5

   Lightning 3.5

   Aircraft 0.5

   Stratosphere 0.1

   Total 40

CO, Tg CO yr-1  

   Fossil fuel combustion 390

   Wood fuel combustion 130

   Biomass burning 510

   Total 1030

Emissions of Ozone Precursors

Species Present-Day 2000

Isoprene, Tg C yr-1    

   Vegetation 550

Ethane, Tg C yr-1    

   Industrial 6.2

   Biomass burning 2.4

   Total 8.6

Propane, Tg C yr-1  

   Industral 6.7

≥C4 alkanes, Tg C yr-1  

   Industrial 30.1

≥C3 alkenes, Tg C yr-1  

   Industrial 10

   Biogenic sources 16

   Biomass burning 12

   Total 38

Acetone, Tg C yr-1  

   Biomass burning 9

   Biogenic sources 14

   Total 23

Emissions of Ozone Precursors (cont.)Emissions of Ozone Precursors (cont.)

1) DMS + OH 0.75 SO2 + 0.25 MSA

2) DMS + OH SO2

3) DMS + NO3 HNO3 + SO2

4) SO2 + OH +M H2SO4 + M

Gaseous Reactions Related to SO2

In the gas-phase, DMS (dimethyl sulfate) emitted from the oceans is oxidized by OH in day-time and by NO3 in night-time, generating SO2. And then SO2 from anthropogenic and natural sources reacts with OH to form sulfate in the gas-phase

Oxidation by O3 is very sensitive to cloud pH: Higher pH leads to more sulfate formation

SOSO2 2 is oxidized by is oxidized by HH22OO22 and O and O3 3 to form sulfate in cloudsto form sulfate in clouds

Aqueous Reactions Related to SO2

Anthropogenic 59.24 Aircraft 0.07 Biomass burning 1.22 Biofuel 0.27 Volcanic 5.48 Ship 4.23 DMS 14.01 Total 84.52

Global SO2 Emission Inventories

(TgS yr-1)

Annual emissions of anthropogenic SO2 over Asia(tonnes/year/0.5°cell)

David Streets 2006 Emission Inventory

Annual emissions of anthropogenic CO over Asia(tonnes/year/0.5°cell)

David Streets 2006 Emission Inventory

Annual emissions of anthropogenic NOx over Asia(tonnes/year/0.5°cell)

David Streets 2006 Emission Inventory

UnitUnit: ppbv: ppbv

Surface-layer Mixing Ratios of O3 (ppbv)

JANJAN JULJUL

Unit: DUUnit: DU

Tropospheric Column Burdens of O3 (DU)

JANJAN JULJUL

UnitUnit: pptv: pptv

JANJAN JULJUL

Surface-layer Mixing Ratios of SO2 (pptv)

Unit: 10Unit: 101515 molecules cm-2 molecules cm-2

JANJAN JULJUL

Tropospheric Column Burdens of SO2 Unit: 10Unit: 101515 molecules cm-2 molecules cm-2

UnitUnit: pptv: pptv

JANJAN JULJUL

Surface-layer Mixing Ratios of NOx (pptv)

Unit: 10Unit: 101515 molecules cm-2 molecules cm-2

JANJAN JULJUL

Tropospheric Column Burdens of NOx Unit: 10Unit: 101515 molecules cm-2 molecules cm-2

Research Plan

Jan-Dec, 2008: Simulation of regional trace gases (such as NOx, SO2, O3, CO, etc.) Simulation of regional trace gases (such as NOx, SO2, O3, CO, etc.)

using GEOS-Chem.using GEOS-Chem. Submission of the med-term progress report in Submission of the med-term progress report in

December 2008.December 2008.

Jan-Dec, 2009: Comparison of model results with satellite retrievals. Submission ofComparison of model results with satellite retrievals. Submission of

the final progress report in December 2009.the final progress report in December 2009.

Thanks!