Implementation of GEM-MACH10, A New Higher-Resolution Version of the Canadian Operational Air Quality Forecast Model Mike Moran 1, Sylvain Ménard 2, Radenko Pavlovic 2, Sylvie Gravel 3, Samuel Gilbert 2, Hugo Landry 2, Wanmin Gong 1, Craig Stroud 1, Sunling Gong 1, and Qiong Zheng 1 1 Air Quality Research Division, Environment Canada, Toronto, Ontario, Canada 2 Air Quality Modelling Applications Section, Environment Canada, Montreal, Quebec, Canada 3 Air Quality Research Division, Environment Canada, Montreal, Quebec, Canada 11 th CMAS Conference, October 2012, Chapel Hill, North Carolina

Canadian AQ Forecasting System Short GEM-MACH15 Overview Changes for GEM-MACH10 Performance of New Model Talk Outline

Primary messaging tool is the Air Quality Health Index (AQHI) Main target is urban areas > 100,000 population GEM-MACH15 AQ / Wx on-line forecast model provides guidance on AQHI component values (NO 2, O 3, PM 2.5 ) and meteorological fields out to 48 hours Canadian AQ Forecasting System

Follows example of Canadian national UV index Year-round, health-based, additive, no-threshold, hourly AQ index Developed from daily time-series analysis of air pollutant concentrations and mortality data (Stieb et al., 2008, J&AWMA) Weighted sum of NO 2, O 3, & PM 2.5 concentrations Range from 0 to 10+ Canada’s National Air Quality Health Index (AQHI)

Elements of Cdn AQ Forecasting System Forecasted future situation - Next 48hr - Modelled forecast values of O 3, PM 2.5, NO 2 Forecaster (1 desk/forecast region) Schematic diagram of an AQHI forecast AQHI = 10/10.4*100*[(exp( *NO 2 )-1) +(exp( *O 3 ) -1)+(exp( *PM 2.5 ) -1)] AQHI = 10/10.4*100*[(exp( *NO 2 )-1) +(exp( *O 3 ) -1)+(exp( *PM 2.5 ) -1)] Numerical forecast - Next 48 hr - GEM-MACH15 UMOS-AQ Past & present situation - Last 48 hr - Real-time observations of O 3, PM 2.5, NO 2

Acronym “GEM-MACH” Stands For modèle Global Environnemental Multi-échelle – Modélisation de la qualité de l'Air et de la CHimie et / and Global Environmental Multiscale model – Modelling Air quality and CHemistry

GEM-MACH is a multi-scale chemical weather forecast model composed of dynamics and physics (GEM) and on- line chemistry modules GEM-MACH15 is a particular configuration of GEM-MACH chosen to meet EC’s operational AQ forecast needs; its key characteristics include: –limited-area-model (LAM) grid configuration for North America –15-km horizontal grid spacing, 58 vertical levels to 0.1 hPa –2-bin sectional representation of PM size distribution (i.e., and μm) with 9 chemical components –forecast species include O 3, NO 2, and PM 2.5 needed for AQHI GEM-MACH and GEM-MACH15

GEM-LAM15 is EC’s limited-area regional weather forecast model GEM-MACH15’s grid points are co-located with GEM-LAM15 grid points GEM-LAM15 supplies meteorological initial conditions and lateral boundary conditions to GEM-MACH15 GEM-LAM15 and GEM-MACH15 Grids GEM-LAM15 core grid (blue); GEM-MACH15 grid (red)

Motivation for GEM-MACH10 New computers – 2 new IBM Power7 clusters were delivered to Environment Canada in early 2012 (faster nodes, more nodes) “Follow the Leader” (need to stay current) – GEM-LAM15 meteorological piloting model was to be replaced by GEM-LAM10 in 2012 (including reduction in horizontal grid spacing from 15 to 10 km)

GEM-MACH10 v1.5.0 Characteristics New version of GEM NWP model source code New GEM-MACH grid configuration (  ~5X more Flops): – domain virtually unchanged, – horizontal grid spacing reduced (15 km to 10 km), – number of σ-p vertical levels increased (58 to 80), – met time step reduced (450 s to 300 s), – chemistry time step unchanged (900 s) Change in meteorological piloting model from GEM-LAM15/3D-Var to GEM-LAM10/4D-Var Mostly same emissions inventories but improved emissions processing, especially for Canadian emissions

Niveaux GEM-MACH GEM-MACH15 (58 levels) GEM-MACH10 (80 levels) Lowest 47 levels are identical

Number of CPUs vs. Execution Time Target time: ~ 30 min Choice: 960 CPUs = 10 x 12 x 8

Changes to Emissions Processing (1) Emissions inventories used: ▪Canada: new version (2006 base year) ▪USA: no change (projection to 2012) ▪Mexico: no change (1999 base year) ▪Biogenics: no change but …

Sommaire des changements apportés au RAQDPS (4) ▪ Corrected and optimized boundary shapefiles ▪ Corrections and improvements to some spatial surrogate fields, including new surrogates for Canadian on-road mobile emissions ▪ Updates to some Canadian temporal profiles ▪ New library of PM speciation profiles and addition of some VOC speciation profiles ▪ Land-use-dependent transportable fraction used to scale fugitive dust emissions ▪ Removal of emissions from shut-down facilities (e.g., Flin Flon, MB) Changes to Emissions Processing (2)

Example: Changes To Spatial Distribution Of Canadian On-road Mobile Emissions– Improved Representation Of Road Type, One Spatial Surrogate Replaced By Set Of 6 Surrogates OldNew

▪ Emissions fields were prepared on GEM- MACH15 grid with SMOKE, then mass- conserving interpolation was used to transfer them to GEM-MACH10 grid; this approach gave better results than preparation directly on 10- km grid (which suggests that scale dependence of some spatial surrogates is not represented properly) Changes to Emissions Processing (3)

Difference Between Old and New Emissions (GEM-MACH15 Grid, July, Kt/month) NO2 SO2 CO NH3 PM2.5 PMC

GEM-MACH10 Chronology June 2009: GEM-MACH15 parallel run begins (2006 Cdn and 2005 U.S. emissions) Oct. 2011: New operational version of GEM-MACH15 with new emissions (2006 Cdn and projected 2012 U.S. emissions) June 2012: Start of GEM-MACH10 parallel run with GEM-MACH15 3 Oct. 2012: GEM-MACH10 v1.5.0 implementation

Objective Scores – Hourly Values Winters, 2011 and

Objective Scores – Hourly Values Summers, 2011 and

Categorical Scores: O 3 Contingency Table GEM-MACH10 vs. GEM-MACH15 – Summer 2012 Canada U.S. Hourly Values, 80 ppb Threshold 10km | OPS

Categorical Scores: PM 2.5 Contingency Table GEM-MACH10 vs. GEM-MACH15 – Summer 2012 Canada U.S. Hourly Values, 35 ug m -3 Threshold 10km | OPS

GEM-MACH10 v1.5.0, a new, higher-resolution version of Environment Canada’s operational AQ forecast model, was implemented on 3 October 2012 Horizontal grid spacing on the North American forecast domain has been reduced from 15 to 10 km Some improvements in model performance are due to improved emissions processing, but meteorological forecasts have also changed The changes in this new version are evolutionary, not revolutionary, and were required in part to keep up with changes to EC’s operational Wx forecast models Conclusions

Thank you for your attention

PM Summertime Forecast Avg PM 2.5 (ug/m 3 ) GM10GM15 OPS Diff: GM10 - GM15

NO Summertime Forecast Avg NO 2 (ppb) GM10GM15 OPS Diff: GM10 - GM15

O Summertime Forecast Avg O 3 (ppb) Diff: GM10 - GM15 GM15 OPS GM10

PM Wintertime Forecast Avg PM 2.5 (ug/m 3 ) Diff: GM10 - GM15 GM15 OPSGM10

NO Wintertime Forecast Avg NO 2 (ppb) GM15 OPS GM10 Diff: GM10 - GM15

O Wintertime Forecast Avg O 3 (ppb) GM10GM15 OPS Diff: GM10 - GM15