The GEOS-CHEM Simulation of Trace Gases over China Li ZHANG and Hong LIAO Institute of Atmospheric Physics Chinese Academy of Sciences April 24, 2008

Global Chemical Transport Model GEOS-Chem Trace Gases NOx, SO2, CO, O3, etc. Concentrations and Distributions over China Simulates Investigate Contents

The GEOS-Chem Global Chemical Transport Model GEOS Assimilated Met Fields Gas-phase Chemistry O 3 -NO x -CO-CH 4 -NMHC Tropospheric Aerosols Gas-phase species Heterogeneous reactions Sulfate/nitrate/ammonium BC/POA/SOA Sea salt Mineral dust Stratospheric Ozone input Anthropogenic Biogenic Anthropogenic Nature Temperature Wind, etc. Alternation of actinic flux

Abbreviation Met Field TypeColor G3 CHGEOS–3GEOS–3 China Nested Grid — 1 x 1 resolution1 x 1 resolution G3 NAGEOS–3GEOS–3 North America Nested Grid — 1 x 1 resolution1 x 1 resolution G3 2x25GEOS–3GEOS–3 Global Grid — 2 x 2.5 resolution2 x 2.5 resolution G3 4x5GEOS–3GEOS–3 Global Grid — 4 x 5 resolution4 x 5 resolution G4 rawGEOS–4GEOS–4 Global Grid — 1 x 1.25 (native) resolution1 x 1.25 (native) resolution G4 2x25GEOS–4GEOS–4 Global Grid — 2 x 2.5 resolution2 x 2.5 resolution G4 4x5GEOS–4GEOS–4 Global Grid — 4 x 5 resolution4 x 5 resolution G5 CHGEOS–5 China Nested Grid — 0.5 x resolution G5 NA GEOS–5 North America Nested Grid — 0.5 x resolution G5 2x25GEOS–5 Global Grid — 2 x 2.5 resolution2 x 2.5 resolution G5 4x5GEOS–5 Global Grid — 4 x 5 resolution4 x 5 resolution Data period: GEOS Met Data

GEOS-3 Met fields

Simulation of Ozone (O 3 ) 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 NO x, Tg N yr -1 Fossil fuel combustion20 Biomass burning11 Soil (natural)3.9 Soil (fertilizer)0.5 Lightning3.5 Aircraft0.5 Stratosphere0.1 Total40 CO, Tg CO yr -1 Fossil fuel combustion390 Wood fuel combustion130 Biomass burning510 Total1030 Emissions of Ozone Precursors

Species Present-Day 2000 Isoprene, Tg C yr -1 Vegetation550 Ethane, Tg C yr -1 Industrial6.2 Biomass burning2.4 Total8.6 Propane, Tg C yr -1 Industral6.7 ≥C 4 alkanes, Tg C yr -1 Industrial30.1 ≥C 3 alkenes, Tg C yr -1 Industrial10 Biogenic sources16 Biomass burning12 Total38 Acetone, Tg C yr -1 Biomass burning9 Biogenic sources14 Total23 Emissions of Ozone Precursors (cont.)

1)DMS + OH  0.75 SO MSA 2)DMS + OH  SO 2 3)DMS + NO 3  HNO 3 + SO 2 4)SO 2 + OH +M  H 2 SO 4 + M Gaseous Reactions Related to SO 2 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 O 3 is very sensitive to cloud pH: Higher pH leads to more sulfate formation SO 2 is oxidized by H 2 O 2 and O 3 to form sulfate in clouds Aqueous Reactions Related to SO 2

Anthropogenic Aircraft 0.07 Biomass burning 1.22 Biofuel 0.27 Volcanic 5.48 Ship 4.23 DMS Total Global SO 2 Emission Inventories (TgS yr-1)

Annual emissions of anthropogenic SO 2 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

Unit: ppbv Surface-layer Mixing Ratios of O 3 (ppbv) JANJUL

Unit: DU Tropospheric Column Burdens of O 3 (DU) JANJUL

Unit: pptv JAN JUL Surface-layer Mixing Ratios of SO 2 (pptv)

Unit: molecules cm-2 JANJUL Tropospheric Column Burdens of SO 2 Unit: molecules cm-2

Unit: pptv JANJUL Surface-layer Mixing Ratios of NO x (pptv)

Unit: molecules cm-2 JANJUL Tropospheric Column Burdens of NO x Unit: 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. Submission of the med-term progress report in using GEOS-Chem. Submission of the med-term progress report in December December  Jan-Dec, 2009: Comparison of model results with satellite retrievals. Submission of the final progress report in December the final progress report in December Thanks!