1. Modelling the Canadian Arctic and Northern Air Quality using GEM-MACH Wanmin Gong and Stephen Beagley Science and Technology Branch Environment Canada 1 st NETCARE Workshop, University of Toronto, November 18 -19, 2013

2. Page 2 – September 24, 2015 Overview of the project Background: The Arctic is recognized as one of the key areas of the globe, both in terms of its sensitivity to climate change, and by the increasing economic activity associated with the opening up of Arctic areas in a warming climate. Under the approved Clean Transportation Treasury Board Submission, Environment Canada has committed to assess the health and environmental impacts of various air pollutants emitted from ships and potential abatement technologies. Approach: Building the Arctic AQ modelling capability based on the on-line GEM-MACH model Assess the current GEM-MACH performance over the arctic region Develop and test new parameterizations as needed/appropriate to represent physical and chemical processes for arctic conditions Comprehensive evaluation of updated GEM-MACH model including the use of new measurement data from the special studies on both fixed and mobile platforms Timeline: short-term: delivery of the modelling platform and configuration to MSC/NPOD for scenario simulations (end of FY 2013/14). longer term: a credible modelling tool to meet scientific research and policy needs for Canadian Arctic air quality (current and future environment).

3. Page 3 – September 24, 2015 GEM-MACH (EC’s on-line AQ forecast model) GEM: Global Environmental Multiscale – Environment Canada’s numerical weather forecast model (global, NA regional, and hi-res configurations) with an extensive physics library. MACH: Modelling Air quality and CHemistry – chemistry and aerosol microphysics, including –Gas-Phase Chemistry: ADOM-II (42 species, 114 reactions, Young & Boris solver) –Aerosol representation: 2 size bins in the standard version (0 -2.5 mm, 2.5 – 10 mm) and 12 size bins (0.01-40.96 µm) in the new experimental version; 9 chemical species (SO4, NO3, NH4, EC, pOC, sOC, CM, SS, H2O) –Aerosol dynamics/microphysics –Inorganic heterogeneous chemistry –Secondary organic aerosol chemistry –Cloud processing (aerosol activation, aqueous-phase chemistry, wet removal of gas and aerosols) –Dry deposition for aerosol particles and gases. –Emissions: anthropogenic (national inventories from U.S, Canada, and Mexico); on-line biogenic emission calculation (BEIS 3.09).

4. Page 4 – September 24, 2015 Model setup and tests (for base year 2010) Model GEM-MACH 2-bin version 12-bin version Domain Canadian Arctic [considerations and constrains] Emission (anthropogenic) NA: “2006” (2006 Canadian inventory and 2005 US inventory projected to 2011) “2010” (2010 Canadian inventory incl. detailed Arctic marine emissions and 2011 US inventory) Global (suppl): Existing global GEM- MACH 2010 HTAP emissions CBC Default profiles: Single profiles for each season (under “clean” or “dirty” condition) “Climatology”: Global GEM-MACH simulation for 2010 averaged to 4 3-month periods MACC-IFS reanalysis: Inness et al. 2013 (ACP) for 2010, daily average (from 3-hly data) Enhanced srn CBC operational GEM-MACH archives

5. Page 5 – September 24, 2015 Science modules and tests Dry deposition over ice and snow: representation of sea ice and revised dry deposition velocities over ice/snow (Helmig et al., 2007 ACP). Wet processing involving ice and snow: implementation of a new parameterization for below-cloud scavenging of size resolve aerosol by snow (Zhang et al., 2013 GMDD); ice and mixed phase cloud processing of gas and aerosols (ice nucleation, gas uptake by ice crystals, and partitioning during freezing/riming). Impact of wild fire emission (from NA) to the Arctic. Inclusion of ocean DMS emission and processing. Halogen chemistry?? Other new processes??

6. Page 6 – September 24, 2015 Preliminary results – comparison with surface obs.

7. Page 7 – September 24, 2015 Impact of dry deposition over sea ice 2010 May averaged surface O3 conc. Difference in averaged O3 conc. “Climate” CBC, new dry deposition over ice/snow (#1596) New dry dep – old (#1596 - #1593), both with “Climate” CBC

8. Page 8 – September 24, 2015 Impact of chemical boundary conditions Snap shot of surface CO conc. at 20 Z, 05/05/2010 “Climate” CBC (#1606)MACC-IFS CBC (#1613)

9. Page 9 – September 24, 2015 Preliminary results: Comparison with ozonesondes

10. Page 10 – September 24, 2015 Research Plans within NETCARE GEM-MACH-arctic model runs (real-time and/or retrospective) for the NETCARE field campaigns and evaluation. Implement the new parameterization for ice nucleation being developed under NETCARE in GEM-MACH coupled with the on-line (size and chemically resolved) aerosols to explore the full interaction between aerosol and dynamics and its role on Arctic weather system. [A fully coupled version of GEM-MACH (including aerosol feedbacks via radiation and cloud droplet nucleation) is being used to participate in the phase II of the Air Quality Model Evaluation International Initiative (AQMEII), focusing on assessing the importance of the interactions between chemistry and dynamics on air quality and weather forecasting].