1. Chemical Weather with GEM-AQ Jacek W. Kaminski Joanna Struzewska Lori Neary Alex Lupu Jonh C. McConnell Atmospheric Modelling and Data Assimilation Laboratory Centre for Research in Earth and Space Science York University Model Evaluation – five year global simulation

2. AMDAL Paris, October 11, 2006  Supported by Canadian Foundation for Climate and Atmospheric Sciences Environment Canada Natural Science and Engineering Research Council of Canada Canadian Foundation for Innovation Canadian Space Agency Transport Canada

3. AMDAL Paris, October 11, 2006 Objectives  Test the robustness of the model  Examine seasonal variations and regional distributions of ozone and other species  Investigate processes in the model to see where improvements may be necessary  Prepare initial conditions for high resolution runs

4. AMDAL Paris, October 11, 2006 GEM model  Global Environmental Multiscale model (Côt é at al.1998)  Operational execution on 0.9 o x0.9 o global grid  4D-VAR continuous objective analysis  5 and 10 day weather forecasts – global  48 hour regional forecast over North America ~15km  Vertical resolution 58 hybrid levels  Top at 10 mb  Coupled with comprehensive physics  GEM-strato research version with model top at 0.1 mb air quality, tropopospheric and stratospheric chemistry  Meso-Global - ~35km resolution

5. AMDAL Paris, October 11, 2006 GEM – dynamical core  Two time level semi-Lagrangian advection semi-implicit scheme  Variable-resolution on an Arakawa C grid in the horizontal with second order accuracy  Many grid configurations are possible Global uniform Global variable Limited area

6. AMDAL Paris, October 11, 2006 Non-staggered finite differences in the vertical with second order accuracy hybrid vertical coordinate (GEM V3.0 and higher) : sigma hybrid GEM dynamical core

7. AMDAL Paris, October 11, 2006 GEM-AQ Modules  on-line implementation Tracer transport Tracer convection Tracer vertical diffusion Gas phase chemistry  Trop. 50 species, ~130 reactions  Trop+strat 75 species, ~200 rections Photodissociation rates (J values from Messy) Wet chemistry Aerosol chemistry and physics  5 size-resolved aerosol types – 12 bins each – 60 tracers Biogenic emissions Lightning NOx emissions

8. AMDAL Paris, October 11, 2006 Simulation Description  Five year simulation (2001-2005)  Results shown are global uniform resolution at 4x4 and 1.5x1.5 degrees, 28 hybrid levels to 10 hPa

9. AMDAL Paris, October 11, 2006 Comparison with Ozonesondes  Monthly and seasonal mean climatology compiled by Logan (1999), 35 stations  Northern hemisphere generally good agreement, some over-prediction in summer boundary layer  Tropical profiles could indicate a poor representation of deep convective transport  Most SH stations have an over-prediction in the 700-200 mb region, and an under- prediction in the upper troposphere

10. AMDAL Paris, October 11, 2006 Station: Churchill (NH) DJF JJA MAM SON

11. AMDAL Paris, October 11, 2006 Station: Natal (Tropics) DJF JJA MAM SON

12. AMDAL Paris, October 11, 2006 Tropospheric Column O 3  Comparison with GOME shows over- prediction in SH  Results improve greatly with increase in horizontal resolution (1.5x1.5 degrees) October 2001 mean GOME, GEM, GOME-GEM Thanks to X. Liu, Harvard-Smithsonian Institute of Astrophysics for GOME data

13. AMDAL Paris, October 11, 2006 Tropospheric column NO 2  Comparison with SCIAMACHY shows some under-estimation, especially around China  Could indicate anthropogenic emissions used are too low in this region  Agreement is better over N. America and Europe

14. AMDAL Paris, October 11, 2006 Tropospheric Column NO 2  July 2004 GEM (left) and GOME (right) Thanks to A. Richter, U. of Bremen for GOME data

15. AMDAL Paris, October 11, 2006 Aura-MLS vs GEM-AQ and GEOS-CHEM  Overall, GEM-AQ captures the dynamical features seen in the MLS CO data  At 100 and 150 hPa, the magnitude of the GEM-AQ CO agrees reasonably well, but at 200 hPa, the model under-predicts by about one half. This could indicate that the biomass burning emissions are too low, or that the CO is not being transported effectively up to the 200 hPa level by deep convection.  In some months (March for example), the biomass burning signature in Africa seen in the MLS data is not seen in the model.

16. AMDAL Paris, October 11, 2006 March 2005 100 hPa  Missing biomass burning signature over Africa but magnitudes elsewhere in range Results for March 2005 at 100 hPa (top), July 2005 at 150 hPa (middle) and October 2005 at 200 hPa (bottom). Note the scales on the Aura-MLS, GEOS-CHEM and GEM-AQ plots are different.

17. AMDAL Paris, October 11, 2006 July 2005 150 hPa  Magnitudes and patterns agree between MLS and GEM-AQ

18. AMDAL Paris, October 11, 2006 October 2005 200 hPa  Under-predict by a factor of 2 at this level

19. AMDAL Paris, October 11, 2006 GEM-AQ vs MOPITT  The comparison with Aura-MLS data shows that the biomass burning emissions used in GEM-AQ are probably too low by a factor of 2  The MOPITT total column CO seems to suggest this as well, but indicate that transport by deep convection may also be weak

20. AMDAL Paris, October 11, 2006 GEM-AQ vs MOPITT GEM-AQ (left) total column CO compared with MOPITT (right) for Februrary 2004 GEM-AQ (left) total column CO compared with MOPITT (right) for August 2004 Units: molec./cm 2

21. AMDAL Paris, October 11, 2006 GEM-AQ vs MOPITT  GEM-AQ under-predicts CO amounts by a factor of 2 around 200 hPa  The large scale dynamical features can be seen in both the models and the satellite measurements  New emissions are being prepared based on fire counts. Once the improvements to emissions have been done, further analysis of the deep convective transport parameterization used in GEM-AQ is needed.

22. Stratosphere-troposphere exchange at high latitudes  Quantify the impact of both the vertical coordinate system and the horizontal resolution on the influx of ozone and STE in an on-line 3D global chemical weather model, GEM-AQ

23. AMDAL Paris, October 11, 2006 GEM vertical coordinates  GEM hybrid vertical coordinate system, where local pressure is:  When rcoef=1, system reverts to essentially sigma coordinates

24. AMDAL Paris, October 11, 2006 Model Simulations  3 global uniform resolution runs: Horizontal 4x4 degrees, vertical coordinates using rcoef=1. Horizontal 4x4 degrees, vertical coordinates using rcoef=1.6 (hybrid) Horizontal 1.5x1.5 degrees, vertical coordinates using rcoef=1.6 (hybrid)

25. AMDAL Paris, October 11, 2006 Ozone fluxes  To assess the ozone inflow, we examine the flux through one model level (with average pressure ~230 hPa) Model RunO 3 Flux (Tg/year) 4x4, rcoef=11202 4x4, rcoef=1.6926 1.5x1.5,rcoef=1.6841

26. AMDAL Paris, October 11, 2006 Ozone fluxes  Based on observations, the influx of stratospheric O 3 is estimated to be ~550 +/- 140 Tg/yr  Models analysed by Prather et al. (2001) have computed a range of 390-1440 Tg/yr

27. AMDAL Paris, October 11, 2006 Ozone fluxes  Improving the resolution alone has a significant impact on the ozone flux and the use of a hybrid coordinate also reduces the flux. This can also be seen in the comparison with the GOME column ozone  With a top at 10 mb and a sponge layer reaching down to about to 50 mb, the circulation in the lower stratosphere will be impacted. Ultimately we need to remove the effect of the sponge; this is the case with a new research version of GEM, GEM-Strato with a lid at 0.1 mb.

28. AMDAL Paris, October 11, 2006 Impact of horizontal resolution GOME data thanks to Xiong Liu (Harvard-Smithsonian Center for Astrophysics, Cambridge, MA). GOMEGEMGOME-GEM 4x4 run Dec 2001 1.5x1.5 run Dec 2001

29. AMDAL Paris, October 11, 2006 Yukon – Alaska fires, 2004  To further understand and quantify the impacts of biomass burning and deep convective transport on the chemical constituents in the upper troposphere

30. AMDAL Paris, October 11, 2006 Emissions  Monthly emissions from the Global Fire Emission Database version 2.0  Distributed into hourly emissions according to the GOES-10 WF_ABBA fire pixel counts  Emission factors from Andreae and Merlet (2001)  Species emitted: CO, NO, CH 3 OH, HCOOH, C 2 H 6, C 2 H 4, C 3 H 8, HCHO, CH 3 COOH, higher alkanes and alkenes, aromatics, toluene  No aerosol particles

31. AMDAL Paris, October 11, 2006 GEM vs. ACE (1/3)

32. GEM vs. ACE (2/3)

33. AMDAL Paris, October 11, 2006 GEM vs. ACE (3/3)

34. AMDAL Paris, October 11, 2006 Ongoing model evaluation Urban  Pacific 2001 – Vancouver  ESCOMPTE – 2001 Marseilles  Krakow – 2005 Regional  North America – surface ozone (PM2.5)  Brazil - TROCCINOX  Quebec fires 2002  EU heat wave - 2006