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, 15-17 October 2012, Chapel Hill, North Carolina
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Implementation of GEM-MACH10, A New Higher-Resolution Version of the Canadian Operational Air Quality Forecast Model Mike Moran 1, Sylvain Ménard 2, Radenko.
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Implementation of GEM-MACH10, A New Higher-Resolution Version of the Canadian Operational Air Quality Forecast Model
Mike Moran1, Sylvain Ménard2, Radenko Pavlovic2, Sylvie Gravel3, Samuel Gilbert2, Hugo Landry2, Wanmin Gong1, Craig Stroud1, Sunling Gong1, and Qiong Zheng1
– 2-bin sectional representation of PM size distribution (i.e., 0-2.5 and 2.5-10 μm) with 9 chemical components
– forecast species include O3, NO2, and PM2.5 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
Old New
▪ 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 2012
2012
2011
Objective Scores – Hourly Values Summers, 2011 and 2012
• 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