1. MPI-CHEMIE Impact of Tropical Deforestation on the Oxidizing Capacity of the Atmosphere Laurens Ganzeveld 1, Lex Bouwman 2, Bas Eickhout 2, Patrick Jöckel 1, Jos Lelieveld 1, Swen Metzger 1, Meryem Tanarhte 1, and the MESSy team 1 1 Max-Planck Institute for Chemistry, Mainz, Germany 2 National Institute for Public Health and theEnvironment (RIVM), Bilthoven, Netherlands. Laurens Ganzeveld 1, Lex Bouwman 2, Bas Eickhout 2, Patrick Jöckel 1, Jos Lelieveld 1, Swen Metzger 1, Meryem Tanarhte 1, and the MESSy team 1 1 Max-Planck Institute for Chemistry, Mainz, Germany 2 National Institute for Public Health and theEnvironment (RIVM), Bilthoven, Netherlands.

2. MPI-CHEMIE The OH Radical: the Atmosphere‘s detergent Oxidizing Capacity of the Atmosphere OH HO 2 recycling source sink NMHC CO, CH 4, CH 2 O CO 2, H 2 O CH 2 O hνhν H2O2H2O2 HO 2 NO 2 NO hνhν NO 2 O 3 + hv O( 1 D) + H 2 O Primary OH Formation OH Recycling urban (U.S.) remote agricultural (U.S.) Wet tropical forest Maritime (pacific) Courtesy: Franz Meixner, from: Chameides LBA-EUSTACH 1

3. MPI-CHEMIE * Courtesy: Jos Lelieveld Oxidizing Capacity of the Atmosphere Major influences on tropospheric OH ForcingMechanismResponse NO x ↑O 3 formation, OH recyclingOH ↑ H 2 O ↑H 2 O + O( 1 D) → 2OHOH ↑ CH 4 ↑CH 4 + OH → productsOH ↓ CO ↑CO + OH → productsOH ↓ NMHC ↑NMHC + OH → productsOH ? Clouds ↑light scattering, multiphase chemistryOH ?

4. MPI-CHEMIE Hypothesis: Deforestation will affect the atmospheric oxidizing efficiency through changes in tracer, energy and water surface exchanges Deforestation will affect the atmospheric oxidizing efficiency through changes in tracer, energy and water surface exchanges Oxidizing Capacity of the Atmosphere This change can only be assessed with coupled chemistry-climate models that explicitly consider the dependence of surface exchanges on land cover and land use properties This change can only be assessed with coupled chemistry-climate models that explicitly consider the dependence of surface exchanges on land cover and land use properties urban (U.S.) remote agricultural (U.S.) Wet tropical forest Maritime (pacific) Future tropical forest? and the interactions between atmospheric chemistry and the hydrological cycle, e.g., the changes in photo-dissociation due to changes in cloud cover

5. MPI-CHEMIE N emissions [kg N km -2 yr -1 ]: fertilizers Land Cover and Land Use Changes: Present-day versus Future Forest fraction [0 - 1] 21001 10Present-day Present-day 1 40 2100

6. MPI-CHEMIE ECHAM’s energy and H 2 O surface exchanges 5 soil layers, T soil Sea ice Bare soil Sea Wet skin surface Snow/ice z0z0 Soil moisture (W s ) turbulence radiation, heat H 2 O Dry deposition ∫(radiation, W s, turb.) In-canopy interactions ∫(turb., chemistry) Soil-biogenic N emissions ∫(W s, T soil, fertil., ecosystem) biogenic VOC emissions ∫(T surf, radiation, ecosystem) and reactive trace gas and aerosol exchanges ECHAM’s tracer, energy and water surface exchanges

7. MPI-CHEMIE ForestPasture LAI [m 2 m -2 ]~ 6-71.5 Canopy height [m]15-300.5 z 0 [m]1-2 0.05 C 5 H 8 emis. [μg C g -1 hr -1 ] 165 NO emis. [ng N m -2 s -1 ]2.60.36 Cult. intensity [0-1]00.2 Fertil. use [ng N m -2 s -1 ]013 CRF [0-1]0.2-0.30.7-0.8 Impact of Land Cover and Land Use Changes on Atmospheric Chemistry: SCM study deforestation Ganzeveld, L., and J. Lelieveld, Impact of Amazonian deforestation on atmospheric chemistry, Geophys. Res. Lett., 31, L06105, doi:10.1029/2003GL019205, 2004. deforestation ΔOH ~ +100 %

8. MPI-CHEMIE Modular Earth Submodel System (MESSy) coupled to GCM ECHAM5 http://www.messy-interface.org http://www.messy-interface.org ECHAM5 Polar Stratospheric Clouds micro-physics and sedimentation Polar Stratospheric Clouds micro-physics and sedimentation Aerosol Physics (& chemistry) Thermodynamical aerosol composition module and size-resolving dynamical module Aerosol Physics (& chemistry) Thermodynamical aerosol composition module and size-resolving dynamical module 14 CO / Radon natural atmospheric tracer, evaluation of tropospheric OH. STE / PBL transport 14 CO / Radon natural atmospheric tracer, evaluation of tropospheric OH. STE / PBL transport Eulerian Transport Schemes Lagrangian Transport Scheme Natural and Anthropogenic Emissions biogenic surface emissions and anthropogenic emissions Natural and Anthropogenic Emissions biogenic surface emissions and anthropogenic emissions Gas-phase and Heterogeneous Chemistry using Kinetic PreProcessor (KPP) Gas-phase and Heterogeneous Chemistry using Kinetic PreProcessor (KPP) MBL Chemistry switchable extension with chemistry scheme MBL Chemistry switchable extension with chemistry scheme Photolysis fast on-line scheme Photolysis fast on-line scheme Diagnostic and Output (e.g., PBL and tropopause height) Diagnostic and Output (e.g., PBL and tropopause height) Scavenging Below and in-cloud scavenging of gases and aerosols Scavenging Below and in-cloud scavenging of gases and aerosols Dry Deposition dry deposition of gases and aerosols Dry Deposition dry deposition of gases and aerosols Convection & Tracer Transport Stratospheric Water Vapor Lightning NOx Coupled chemistry-GCM

9. MPI-CHEMIE IMAGE, 19 land cover Classes Experiment Set-up: Scenario Compilation Experiments with MESSy-echam5: 1995-2050-2100 A2 land cover and land use scenario’s of the IMAGE model N emissions [kg N km -2 yr -1 ]: fertilizers Forest fraction [0 - 1] 2100 1 10 Present-day Present-day 1 40 2100 Land cover/Land use param.Process Forest fraction micro-met./dry dep. LAI " " Canopy height " " Roughness " " Foliar densitybiogenic VOC emis. C 5 H 8 emis. factor " " LAD profile " " NO emis. factorbiogenic NO emis. Cultivation. intensity " " Fertilizer. use " " Land cover/Land use param.Process Forest fraction micro-met./dry dep. LAI " " Canopy height " " Roughness " " Foliar densitybiogenic VOC emis. C 5 H 8 emis. factor " " LAD profile " " NO emis. factorbiogenic NO emis. Cultivation. intensity " " Fertilizer. use " "Present-day Agric. Land Grassland Regrowth forest Ice Tundra Wooded tundra Boreal forest Cool conifer forest Temp. mixed forest Temp. dedic. forest Warm mixed forest Grassland/steppe Hot desert Scrubland Savanna Tropical woodland Tropical forest 2100 Agric. Land Grassland Regrowth forest Ice Tundra Wooded tundra Boreal forest Cool conifer forest Temp. mixed forest Temp. dedic. forest Warm mixed forest Grassland/steppe Hot desert Scrubland Savanna Tropical woodland Tropical forest

10. MPI-CHEMIE Impact of Land Cover and Land Use Changes: Meteorology dT surf [ºK] 2 2050 - 1995 -2.5 0 dNet surface radiation [%] 2050 - 1995 20% 0% -20% dSoil Moisture [%] 2050 - 1995 -30% 0% 30% dWet skin fraction [%] 2050 - 1995 100% 0% -100%

11. MPI-CHEMIE Impact of Land Cover and Land Use Changes: Surface Exchanges Biogenic Emissions and Dry Deposition change in Foliar Density 2050 - 1995 50% -50% 0% V d HNO 3 ; 2050 - 1995 25% -40% 0% 60% -60% V d O 3 ; 2050 - 1995 50% 0% -100% F NO ; 2050-1995 F C5H8 ; 2050 - 1995 50% 0% -150% ΔF c5H8 ~ Δ biomass ΔF NO ~ ΔCRF, T soil, ws, precip, fert. ΔV dHNO3 ~ Δturbulence ΔV dO3 ~ Δturb., R stom, ws, wet skin fraction

12. MPI-CHEMIE Impact of Land Cover and Land Use Changes: Oxidizing capacity Oxidizing Capacity NO x ; 2050 - 1995 60% 0% -100% C 5 H 8 ; 2050 - 1995 90% 0% -150% 100% 0% -50% OH; 2050 - 1995 15% 0% -20% O 3 ; 2050 - 1995 ΔC 5 H 8 ~ ΔF C5H8 ΔNO x ~ ΔF NO, chemistry, dry deposition ΔO 3 ~ ΔC 5 H 8, dry deposition ΔO 3 ~ ΔNO x ΔOH ~ ΔC 5 H 8 - - + +

13. MPI-CHEMIE Impact of Land Cover and Land Use Changes: Oxidizing capacity Oxidizing Capacity 100% 0% -50% OH; 2050 - 1995 70% 35% 0% -50% 11 5 9 7 3 1 Height [km]

14. MPI-CHEMIE Conclusion/Outlook Including more feedbacks in model experiments: I.Using consistent anthropogenic emission scenarios: IMAGE land cover/use scenarios are consistent with SRES scenarios II.Including aerosol-radiative forcing effects III.Coupling emissions/dry deposition to carbon cycle model (ECHAM5-JSBACH) IV.Coupled ocean-atmosphere simulations  Consequently, we will perform longer integrations/transient simulations to study the significance of the climate change signal; 1-year annual mean dT surf [ºK] 2 2050 - 1995 -2.5 0  Our study indicates that deforestation will generally result in an increase in the oxidizing capacity of the atmosphere, largely reflecting the decreases in isoprene emissions  It does not include for example the potential role of the natural and anthropogenic emissions of oxygenated VOC’s for the OH production  However, the analysis only considers the impact of land-cover and land-use changes on atmospheric chemistry, for a 1-year integration for 1995 and 2050

15. MPI-CHEMIE Outlook: Process Representation Impact of deforestation on soil-biogenic NO x emis.; DayCent, Kirkman, Meixner et al., (submitted) Introducing more mechanistic representation of soil-biogenic N emissions Introducing more mechanistic representation of soil-biogenic N emissions Role of subgrid-scale land conversion: non-linear effects on meteorology and atmospheric chemistry; Role of subgrid-scale land conversion: non-linear effects on meteorology and atmospheric chemistry; Single-Column Model, Meso-scale models, e.g., RAMS Single-Column Model, Meso-scale models, e.g., RAMS 70-80 km echam5-T106 > 100 km

16. MPI-CHEMIE

17. Conclusions/Outlook: Scenario Compilation How realistic are the IMAGE land cover and land use scenarios? How realistic are the IMAGE land cover and land use scenarios? Comparison with local/regional scale land cover and land use management scenarios LAI: IMAGE-2050 – IMAGE-1995 3.5 0 -2.5 LAI: IMAGE-1995 – Olson-1995 3.5 0 -2.5 Olson ’92, 72 ecosystems & NDVI data: annual cycle in biomass IMAGE, 19 land cover classes, 10-year interval

18. MPI-CHEMIE Laurens Ganzeveld: Introduction: the oxidizing capacity is also often referred to as the clean(s)ing capacity since the oxidation of precursor gasses such as methane, CO and SO 2 results in the production of more soluble and reactive reaction products which are more efficiently being removed by wet and dry deposition or prone to further chemical destruction. So a change in the oxidizing capacity of the atmosphere will result in a change in the atmospheric lifetime of many precursors such as methane is therefore also relevant to climate change. Laurens Ganzeveld: Introduction: the oxidizing capacity is also often referred to as the clean(s)ing capacity since the oxidation of precursor gasses such as methane, CO and SO 2 results in the production of more soluble and reactive reaction products which are more efficiently being removed by wet and dry deposition or prone to further chemical destruction. So a change in the oxidizing capacity of the atmosphere will result in a change in the atmospheric lifetime of many precursors such as methane is therefore also relevant to climate change.