Status of the New Canadian Air Quality

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• Status of the New Canadian Air Quality
• Forecast Model GEM-MACH15
• Michael Moran1, Donald Talbot2, Sylvain Ménard2,
  Véronique Bouchet1,
• Paul Makar1, Wanmin Gong1, Alexander Kallaur3,
  Hugo Landry2, Ping Huang4, Sunling Gong1,
  and Louis-Philippe Crevier2
• 1Air Quality Research Division, Environment
  Canada, Toronto, Ontario
• 2Air Quality Modelling Applications Section,
  Environment Canada, Montreal, QC
• 3Air Quality Research Division, Environment
  Canada, Montreal, Quebec
• 4Independent consultant, Toronto, Ontario

8th CMAS Conference Chapel Hill, NC 19
October 2009
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Talk Outline

• Background
• GEM-MACH General description
• GEM-MACH15 Configuration
• GEM-MACH15 Performance evaluation
• Current status

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Environmental Forecasting at EC

• Daily weather forecasts plus
• Ocean waves and storm surges
• Sea ice
• Air pollution potential
• Volcanic ash
• UVB index and total column O3
• Surface O3, PM2.5, and PM10
• AQ Health Index (AQHI based on O3, PM2.5, and
  NO2)
• Hazardous releases (e.g., Chernobyl, FMD, ...)

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Chronology of EC Air-Quality Prediction Program

• 1998 Experimental CTM-based forecasts of
• ground-level O3 begin for eastern Canada
• with CHRONOS (40-km grid spacing)
• 2001 Operational CHRONOS ozone forecasts begin
  
• new national domain, 21-km grid spacing
• 2003 Bulk PM2.5/PM10 forecasts added to CHRONOS
  
• output suite (4 chemical components)

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Objective for GEM-MACH15 Project

• (Autumn 2005) To replace CHRONOS, the current
  EC operational off-line regional AQ forecast
  model for O3, NO2, PM2.5, and PM10, with a new
  GEM-based on-line operational AQFM that includes
  a science package equivalent to the one in the
  AURAMS CTM

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Terminology

• What is GEM?
• Environment Canadas operational
  global/medium-range and regional/short-range
  weather forecast model
• What is GEM-MACH?
• GEM with on-line chemistry from AURAMS CTM
• What is GEM-MACH15?
• proposed operational limited-area configuration
  of GEMMACH with 15-km grid spacing

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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

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"Multiscale" ExamplesThree GEM Grid
Configurations
global
regional
limited area
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GEM-MACH Data Flow
(2005/6) CAN-USA-MEX Emission inventories
SMOKE
off-line system
GenPhysX Biogenic info (Beld3, emis factor)
Area
Major points
Climatology
Geophys
Meteorological Analysis
RPN standard file format
RPN standard file format
GEM-MACH Emissions pre-processor
GEM Meteorological pre-processor
on-line system
Emissions binary files for each CPU tile
Meteorological binary files for each CPU tile
GEM-MACH Main model
PM2.5, O3, NO2, ... Temperature, pressure
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Chemical Process Representations in CHRONOS vs.
GEM-MACH15
PROCESS CHRONOS GEM-MACH15
Emissions PM2.5 and PMc primary emissions are assumed to be bulk emissions 17 gas-phase species emitted PM2.5 and PMc emissions speciated to 7 species by primary source type (point, area, mobile) 17 gas-phase species emitted
Gas-Phase Chemistry Mechanism ADOM-2 mechanism (Stockwell and Lurmann, 1989) 47 advected species ADOM-2 mechanism (Stockwell and Lurmann, 1989) with 1) p-SO4 replaced by H2SO4p-SO4 2) N2O5 H2O heterogeneous nitrate formation rate enhancement switchoff.
Aqueous-Phase Chemistry None ADOM aqueous-phase chemistry
PM Composition and size distribution 2 size bins PM2.5, PM10 4 chemical species sSO4, sOC, H2O, primary PM 2 size bins PM2.5, PM10 8 chemical species SO4, NO3, NH4, EC, pOC, sOC, CM, SS
Aerosol Dynamics Sedimentation Sedimentation, Nucleation, Condensation, Coagulation
Secondary Organic (SOA) Yields Based on Pandis et al. (1992) IAY scheme Based on Jiang (2004)
Wet Deposition Distribution of LWC is used to calculate the wet scavenging term by applying Sundqvist formulae for the rate of release of precipitation Transfer of tracers from cloud to rain water based on precipitation production. In-cloud and below-cloud scavenging of soluble gases and particles (size-dependent) .
Chemical boundary conditions Zero-gradient inflow, open-boundary out-flow Climatological profiles with Davies lateral boundary conditions
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Simplifications to GEM-MACH15 for Operational Use

• Perform meteorological calculations every time
  step (450 s) but AQ calculations every 2nd
  time step (900 s)
• Used 58 vertical levels to 0.1 hPa rather than 80
  levels to 0.1 hPa used by GEM15
• Used metastable option in heterogeneous chemistry
• Switched from 12-bin to 2-bin representation of
  PM size distribution reduces number of advected
  tracer fields by 80 from 137 to 57, i.e., by
  60, but had to implement new sub-bin
  calculations to account for size dependence in
  some PM processes (sea-salt emissions, dry
  deposition, intersectional transport)

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GEM15 and GEM-MACH15 Grids

• GEM15 employs a variable grid, but uniform core
  has 15-km spacing
• GEM-MACH15 employs a limited-area grid (LAM),
  also with 15-km spacing and co-located with GEM15
  grid points
• GEM15 supplies meteorological initial conditions
  and hourly lateral boundary conditions to LAM

GEM15 core grid (red) GEM-MACH15 grid (blue)
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CHRONOS and GEM-MACH15 Setups
CHRONOS
GEM-MACH15

• 350 x 250, polar stereographic projn
• horizontal grid spacing of 21 km
• 24 Gal-Chen vertical levels to 6 km
• ?t 3600 s
• Emissions 2000 Canadian 2001 US with
  adjustments to 2007 EGU levels

• 348 x 465, rotated lat-long projection
• horizontal grid spacing of 15 km
• 58 eta hybrid levels to 0.1 hPa
• ?t 450 s for meteorology
• ?t 450 x 2 900 s for chemistry
• Emissions 2006 Cdn, 2005 US, 1999 Mx

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Summer 2009 "Parallel Run" Evaluation

• GEM-MACH15 was run in parallel alongside
  CHRONOS from May 27 to Aug. 17, 2009
• Subjective evaluation
• CMC and regional AQ forecasters (6 offices)
• comparison to GEM15, to local AQ measurements,
  and to CHRONOS
• Objective evaluation
• discrete statistics (with significance testing)
• categorical statistics

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Example of Day 2 Hourly O3 Comparison (Full
Domain)
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Example of Day 1 Hourly NO2 Comparison (Full
Domain)
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Example of Day 1 Hourly PM2.5 Comparison (Eastern
North America)
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Summer 2008 O3 and NO2 Monitor Locations
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CHRONOS vs. GEM-MACH15Discrete Statistics
June-July-Aug. 2009
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CHRONOS vs. GEM-MACH15Categorical Statistics
June-July 2009

• Percent Correct (PC) is in CHRONOSs favour for
  this period
• O3 0.77 (0.80) PM2.5 0.73 (0.77)
• Probability of Detection (POD) is slightly in
  favour of GEM-MACH15
• False Alarm Rate (FAR) and Critical Success
  Index (CSI) are comparable for two models for
  this period

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Outcome of "Parallel Run" Evaluation

• Request at the Sept. 3, 2009 meeting of the
  Committee on Operational and Parallel Runs at the
  Canadian Meteorological Centre (CMC) for
  GEM-MACH15 to be elevated to operational status
  was accepted
• Final modifications to GEM-MACH15 operational
  suite are now being completed the switch from
  CHRONOS to GEM-MACH15 is expected the week of
  Oct. 26th
• GEM-MACH15 is a better platform for further
  development and improvements
• Entire effort has taken about 4 years

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Thank you for your attention!