1. MOZART Development, Evaluation, and Applications at GFDL MOZART Users’ Meeting August 17, 2005 Boulder, CO Arlene M. Fiore Larry W. Horowitz Arlene.Fiore@noaa.gov Larry.Horowitz@noaa.gov

2. Outline: MOZART Development, Evaluation, and Applications at GFDL Surface Ozone Bias over the United States -Comparison with observations (EPA AQS; CASTNet) -Sensitivity -Policy-relevant background Evaluation with 2004 ICARTT observations * Vertically distributed biomass burning Trends (historical, future) in ozone and aerosols Methane control for climate and air quality –1990-2004 CMDL CH 4 * * Special thanks to George Milly, the ICARTT Science Team, CMDL

3. MOZART-2 Comparison with AIRS: July 2001 1-5 p.m. Surface O 3 (ppbv) Mean Bias = 24±10 ppbv; r 2 = 0.50

4. FiresLand biosphere Human activity Ocean NORTH AMERICA NORTH AMERICA Lightning “Background” air Outside natural influences Long-range transport of pollution Processes Contributing to Surface Ozone over North America stratosphere lightning “POLICY RELEVANT BACKGROUND” (PRB) OZONE: Ozone concentrations that would exist in the absence of anthropogenic emissions from North America X

5. Daily afternoon (1-5 p.m. mean) surface ozone from all CASTNet sites for March-October 2001: PRB ozone over the U.S. is typically 20-35 ppbv CASTNet sites GEOS-CHEM Model PRB 26±7 ppbv GEOS-CHEM PRB 29±9 ppbv MOZART-2  Both models predict consistent PRB range despite large surface O 3 bias in MOZART-2 MOZART-2 Model

6. MOZART-2 bias associated with domestic ozone production MODEL – OBSERVED Daily mean 1-5 p.m. June 1 – Aug 31 at CASTNet stations -50 0 50 100 150 Background O 3 North American O 3 80 60 40 20 0 200 150 100 50 0 -50 0 50 100 150 Slope = -0.14; intercept=25;r=-0.38 Slope = 0.81; intercept=33;r=0.65

7. Substantial O 3 sensitivity to the uncertain fate (and yield) of organic isoprene nitrates OH RO 2 NO(very fast) NO 2 High-NO x Isoprene nitrates Sink for NO x ? ISOPRENE O3O3 Change in July mean 1-5 p.m. surface O 3 when isoprene nitrates (at 12% yield) act as a NO x sink  4-12 ppbv impact! ppbv MOZART-2 Fiore et al., JGR, 2005

8. MOZART-4 Fully Interactive Base case +21 ppbv Change in eastern U.S. surface ozone bias due to sensitivity simulations Base case = simulation with isop. nitrates as a NO x sink MOZART-2 Base case +19 ppbv O 3 deposition velocities*1.5 PAN, NO 2 dep vels. = O 3 Including alkyl nitrate formation SYNOZ No isop. peroxide recycling Daytime PBL increased to 2 km Xactive phot/emis (not drydep) All Xactive; no clouds in phot. Daytime PBL increased to 1 km Xactive drydep/emis (not phot)

9. Outline: MOZART Development, Evaluation, and Applications at GFDL Surface Ozone Bias over the United States -Comparison with observations (EPA AQS; CASTNet) -Sensitivity -Policy-relevant background Evaluation with 2004 ICARTT observations Vertically distributed biomass burning Trends (historical, future) in ozone and aerosols Methane control for climate and air quality –1990-2004 CMDL CH 4 *

10. COMPARISON WITH ICARTT : Mean % Bias MOZART-4 (preliminary version) NCEP T62, 1999 NEI vs. All INTEX DC-8 observations June-Aug 2004

11. OZONE (ppb) CO (ppb) H 2 O 2 _CIT (ppt) HNO 3 _CIT (ppt) PAN (ppt) NO x (ppt) Altitude (km) Campaign Mean Vertical Profiles Model vs. INTEX DC-8 Observations

12. Ozone Chemical Regime Model vs. INTEX DC-8 Observations (day; <2km; east of 100 °W) Model more HOx-rich (i.e., NO x -sensitive) and shows a stronger HO x -NO x correlation than observed. HO 2 vs. NO 2

13. Outline: MOZART Development, Evaluation, and Applications at GFDL Surface Ozone Bias over the United States -Comparison with observations (EPA AQS; CASTNet) -Sensitivity -Policy-relevant background Evaluation with 2004 ICARTT observations Vertically distributed biomass burning Trends (historical, future) in ozone and aerosols Methane control for climate and air quality –1990-2004 CMDL CH 4 *

14. Vertically Distributed Biomass Burning (BMB) Emissions 1. IPCC AR-4 BASE CASE (met year 2000) -- monthly 1997-2002 mean van der Werf emissions -- levels with tops at 0.1, 0.5, 1, 2, 3, and 6 km 2. ICARTT Summer 2004 -- daily emissions from Rynda Hudman & Solene Turquety, Harvard -- distributed up to 4 km, with 50% below 1 km

15. Change in SON composite max* CO concentrations (ppb) (Vertically distributed) – (All at surface) 300 hPa 750 hPa 995 hPa 500 hPa *Composite max = daily max per grid point increases just above the boundary layer decreases at surface and higher altitudes; interplay btw emissions and convection?

16. Change in Tropospheric O 3 Columns (DU) Composite Seasonal Maxima* (Vertically distributed) - (All BMB emissions at surface) JJASON DJF MAM Maximum impact ~10% near source region *Composite max = daily max per grid point -3 -2 -1 0 1 2 3

17. Outline: MOZART Development, Evaluation, and Applications at GFDL Surface Ozone Bias over the United States -Comparison with observations (EPA AQS; CASTNet) -Sensitivity -Policy-relevant background Evaluation with 2004 ICARTT observations * Vertically distributed biomass burning Trends (historical, future) in ozone and aerosols Methane control for climate and air quality –1990-2004 CMDL CH 4 *

18. 1860188019001920194019601980200020202040206020802100 NO x Emissions (Tg N) SO 2 Emissions (Tg SO 2 ) BC Emissions (Tg C) 120 100 80 60 40 20 250 200 150 100 50 0 25 20 15 10 5 0 1860188019001920194019601980200020202040206020802100 BC Burden (Tg C) SO 4 Burden (Tg S) O 3 Burden (DU) 50 45 40 35 30 25 20 15 10 5 876543210876543210 1.6 1.4 1.2 1. 0.8 0.6 0.4 0.2 0 Emission trends in MOZART-2 and resulting tropospheric burdens, used to drive GFDL climate model simulations for IPCC [Horowitz, in prep.]

19. 1860: Mean=24.1 DU2000: Mean= 34.0 DU A2 2100: Mean 45.4 DU Trends in Tropospheric O 3 Columns [Horowitz, in prep.] First step; next we’ll examine climate impacts on chemistry with GFDL chemistry-climate model

20. Ozone Budgets in IPCC-AR4 from 19 Tropospheric Chemistry Models for Base Year 2000 PRODLOSSDEPSTRAT Ozone (Tg yr -1 ) Budgets from Stevenson et al., 2005 X 19-Model Mean MOZART-2 MOZART-4 X MOZECH GEOS-CHEM Scenarios for 2030: Current Legislation (CLE) Maximum Feasible Reductions SRES A2 Climate change (CLE emissions) Emissions for 2000: EDGAR 3.2 GFED 1997-2002 mean for biomass burning

21. Outline: MOZART Development, Evaluation, and Applications at GFDL Surface Ozone Bias over the United States -Comparison with observations (EPA AQS; CASTNet) -Sensitivity -Policy-relevant background Evaluation with 2004 ICARTT observations Vertically distributed biomass burning Trends (historical, future) in ozone and aerosols Methane control for climate and air quality –1990-2004 CMDL CH 4 *

22. MOZART-2 Methane Study Motivation: Methane controls benefit global air quality and climate by lowering background tropospheric O 3 Question: Are prior results from steady-state simulations with uniform, fixed CH 4 concentrations directly relevant to real-world emission controls? Approach: Multi-decadal transient simulations Reduce global anthrop. CH 4 emissions by 40%: (1) All in Asia (2) Everywhere in the globe (All simulations use 1990-2004 T62 NCEP winds, recycled as needed)

23. Methane Emissions in EDGAR inventory: early 1990s (Tg CH 4 yr -1 ) Anthropogenic: 248 Based on values in the literature, we increased biogenic CH 4 emissions by 60 Tg 95 93 60 86 204 10Total: 548

24. Seasonal cycle, inter-annual variability, increasing trend largely captured at remote sites Underestimates post-1998; indicating emissions increase? MODEL CH 4 CMDL CH 4 1990 1992 1994 1996 1998 2000 2002 1780 1760 1740 1720 1700 1760 1740 1720 1700 1680 1780 1760 1740 1720 1700 1680 1660

25. High Bias at high northern latitudes Low bias at high southern latitudes 1990 1992 1994 1996 1998 2000 2002 MODEL CH 4 CMDL CH 4 1720 1700 1680 1660 1640 1800 1780 1760 1740 1720 1900 1850 1800 1750 1990 1992 1994 1996 1998 2000 2002 Low Bias at high southern latitudes Inter-hemispheric gradient too high

26. Decrease in Tropospheric CO Burden Transient simulations with EDGAR 1990 emissions, beginning 1990: (1) Standard (2) 40% decrease in global anthrop. emissions (18% of total CH 4 emissions) Global surface CH 4 conc. Decrease in global surface CH 4 conc. (standard – 40% anth. emis. decrease Decrease in Tropospheric O 3 Burden

27. CLIMATE IMPACTS: Change in July 2000 Trop. O 3 Columns (to 200 hPa) 40% decrease in global anthrop. CH 4 emissions Zero CH 4 emissions from Asia (= 40% decrease in global anthrop.) No Asia – (40% global decrease) Tropospheric O 3 column response is independent of CH 4 emission location except for small (~10%) local changes Dobson Units DU

28. U.S. Surface Afternoon Ozone Response in Summer also independent of methane emission location MEAN DIFFERENCE MAX DIFFERENCE (Composite max daily afternoon mean JJA) NO ASIAN CH 4 GLOBAL 40% DECREASE IN ANTHROP. CH 4  Stronger sensitivity in NO x -saturated regions (Los Angeles), partially due to local ozone production from methane

29. Summary: MOZART Development, Evaluation, and Applications at GFDL Surface Ozone Bias over the United States –Typically 15-20 ppbv; sensitive to local chemistry Evaluation with 2004 ICARTT observations –Generally good; many species too high in boundary layer Vertically distributed biomass burning –Small mean effect, up to ~10% episodically Trends (historical, future) in ozone and aerosols –Past increases, future increases under some scenarios –First step towards studying chemistry-climate interactions –MOZART-2 near ensemble mean in IPCC 2030 comparisons Methane control for climate and air quality –Good agreement btw transient runs and remote surface obs. –Nearing steady-state after 30 years (~3 e-folding lifetimes) –40% anthrop. CH 4 decrease  -9 Tg O 3 ; -(1-3) ppbv U.S. JJA –Ozone response largely independent of CH 4 source location