1. Lupu, Semeniuk, Kaminski, Mamun, McConnell
GEM-AC update
Lupu, Semeniuk, Kaminski, Mamun, McConnell
ACE STM – May 16, 2013

2. Outline Model description Evaluation against surface observations
O3 and temperature (N America GV 30-km run)
Aerosols (global 3°×3° run)
Evaluation against ACE-FTS profiles
O3, NOy, CO etc. (global 3°×3° run)
To do

3. GEM-AC − Model Description
A stratospheric–tropospheric global and regional model for air quality and climate change
Based on the global general circulation/weather forecast model GEM (Global Environmental Multiscale) – version 3.3.2
Gas-phase chemistry: detailed reaction scheme including Ox, NOx, HOx, CO, CH4, NMVOCs, halocarbons, ClOx and BrOx
Aerosols:
Modal model M7 handles microphysics
ISORROPIA calculates gas–aerosol partitioning
Advection: semi-Lagrangian scheme native to GEM
Vertical transport:
Parameterized subgrid scale turbulence and
deep convection
Dry deposition: implemented as a flux boundary condition in the vertical diffusion equation
Wet deposition and cloud chemistry
Emissions:
Yearly-averaged anthropogenic and monthly-averaged biogenic, ocean, soil, and biomass burning emission fluxes, NOx from lightning
CH4, N2O and halogenated species are given as lower boundary conditions
Aerosol and precursor (NH3 and DMS) emissions are from AeroCom

4. GEM-AC monthly mean surface temperature vs. CASTNet observations

5. GEM-AC monthly mean surface ozone vs. CASTNet observations

6. GEM-AC annual mean surface fine sulphate

7. GEM-AC annual mean surface total sulphate

8. GEM-AC annual mean surface sodium

9. GEM-AC annual mean surface nitrate

10. GEM-AC annual mean surface ammonium

11. Ozone

12. Water Vapor

13. Nitrous Oxide

14. Methane

15. NOx

16. NOy

17. Hydrogen Chloride

18. Carbon Monoxide

19. Formaldehyde

20. Formic Acid

21. To Do
Investigate the HOx/NOx maximum in the upper tropical troposphere
Incorporate PSC chemistry
Add missing sources for formic acid, ethane, etc.
Raise the model lid?
Investigate the overestimation of surface ozone in summer over Eastern N America
Add SOA
A more comprehensive evaluation of the aerosol (optical depth, wet deposition)
???