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www.ec.gc.ca. AURAMS Case Studies: Low Resolution Agricultural, High Resolution Urban, Low Resolution PAH simulations. Presented by Paul Makar , Air Quality Modelling and Integration Unit Environment Canada Contributors: NH 3 : Annie Duhamel, Sophie Cousineau,Veronique Bouchet,
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www.ec.gc.ca AURAMS Case Studies: Low Resolution Agricultural, High Resolution Urban, Low Resolution PAH simulations. Presented by Paul Makar, Air Quality Modelling and Integration Unit Environment Canada Contributors: NH3: Annie Duhamel, Sophie Cousineau,Veronique Bouchet, Roxanne Vinzgaran, Colin DiCenzo PrAIRie2005: Brian Wiens, Sunhee Cho, John Liggio, Craig Stroud, Mike Moran, Wanmin Gong, Sunling Gong PAH: Elisabeth Galarneau, Mourad Sassi, Miriam Diamond (U of T) Contact: firstname.lastname@ec.gc.ca
Three Studies • NAESI : National Agro-Environmental Standards Initiative, Air Theme. • Focus: the effects of NH3 on particulate matter formation. • Multi-disciplinary study, Environment Canada in collaboration with Agriculture and Agri-Foods Canada • Air-Theme: overall budget of ~$1.5M/year, 3 years (2007/08 is concluding year). • Monitoring networks • Measurement intensives • Emissions studies • Emissions database • Modelling : Scenarios with old and new NH3 emissions inventories. AURAMS and CMAQ simulations.
Three Studies • PrAIRie2005: Measurement intensive around and over the city of Edmonton, late summer 2005. • 2 instrumented aircraft, 4 instrumented mobile laboratories (3 with Chemistry, one LIDAR). • Comparisons of observations to 21km and nested 3km resolution AURAMS simulations
Three Studies • AURAMS-PAH • Emissions processing system input files modified to estimate PAH emissions relative to total VOC emissions from different sources. • Chemistry and partitioning of PAHs (two methods) added to AURAMS (6 gas-phase species, 6x12 particle bins) • Initial simulations on Continental scale domain will be shown.
NAESI Simulations • What would be the effect of reductions in ammonia emissions on PM2.5 mass in Canada and the USA? • What is the chemistry linking ammonia and PM2.5, and how would it change if ammonia emissions are decreased?
NAESI Simulations • In Canada (and USA), most of the ammonia emissions are related to agricultural activity: 2000 Emissions Inventory! Buyer Beware!
NAESI Simulations – Models Used • AURAMS: • National level scenarios • Continental 42km domain • CMAQ • Regional Case Study, Lower Fraser Valley (Vancouver Area) • 4km resolution (nested)
NAESI Simulations - AURAMS • Using the existing/old inventory, 3 scenarios: • 20% NH3 emission reduction in Canada only • 20% NH3 emission reduction in USA only • 20% NH3 emission reduction in both countries • Compared to Base Case 2002 annual run • Six months for each scenario (June November, 2002). • More scenarios planned with new inventory
NAESI - Model evaluation against observations PM2.5 ammonia: comparison with obs. : Scatterplots of measured vs. predicted 2002 annual p2.5-NH4 mass (mg/m3, STP) by observing network: Moran, M.D., Q. Zheng, and M. Samaali, 2007. Long-term multi-species performance evaluation of AURAMS for first 2002 annual run. EC internal report, Toronto, Ontario (in preparation).
NAESI Simulations - AURAMS • Example: USA, Canada both reduce NH3 emissions by 20%. • Examine change in: • PM2.5 concentration (mg/m3) • p-NH4 / [ 2 p-SO4 + p-NO3] (mole ratio) • … and several other metrics • Compare June and November 2002
NAESI Simulations - AURAMS June 2002: PM2.5 concentration change with 20% reduction in North American NH3 emissions. Base Case - Scenario Note logarithmic scale Max reduction 3 to 5 ug/m3, Los Angeles. Large scale reductions of > 0.5 ug/m3 in eastern N. America
NAESI Simulations - AURAMS June 2002: PM2.5 concentration percent change with 20% reduction in North American NH3 emissions. Base Case - Scenario Max reduction 15%
NAESI Simulations - AURAMS November 2002: PM2.5 concentration change with 20% reduction in North American NH3 emissions Note logarithmic scale. Max reduction >5 ug/m3, Los Angeles. Large scale reductions of > 1 ug/m3
NAESI Simulations - AURAMS November 2002: PM2.5 concentration percent change with 20% reduction in North American NH3 emissions Max reduction of 65%. Big effect on PM2.5 mass in Canadian Prairies, with reductions of > 50% common. changes on order of 20% in USA. i.e. > 1 ug/m3 is a large part of the total PM2.5 in the Prairies in the winter.
NAESI Simulations - AURAMS • Analysis: What is the simulated particle charge ratio ? June: Base Case p-NH4 /(2 p-SO4 + p-NO3): Note logarithmic scale. Values < 1 are acidic
NAESI Simulations - AURAMS • Analysis: How does the simulated particle charge ratiochange with reductions in NH3 emissions? June: DBase Case p-NH4 /(2 p-SO4 + p-NO3): Note logarithmic scale. Base Case - Scenario shown. A lot of noise! Ratio For scenario is lower over eastern area; particles becoming slightly more acidic, but difference is small. Although the regime shifts towards higher acidity in the west, the particle acidity does not change much.
NAESI Simulations - AURAMS • Analysis: What is the simulated particle charge ratio ? November: Base Case p-NH4 /(2 p-SO4 + p-NO3): Note logarithmic scale. Values < 1 are acidic
NAESI Simulations - AURAMS • Analysis: How does the simulated particle charge ratiochange with reductions in NH3 emissions? Nov: DBase Case p-NH4 /(2 p-SO4 + p-NO3): Base case – scenario Note logarithmic scale. Blue regions: less acidic particles In region of maximum decrease of PM2.5, particles in Prairies are becoming less acidic (!). US midwest: particles becoming slightly more acidic.
NAESI Simulations - AURAMS Summary: • Magnitude of effects is very dependant on season and region. • 20% NH3 emission reduction: PM2.5 decreases by ~0.5 ug/m3 summer, ~1 ug/m3 in the winter. • 20% NH3 emission reduction: PM2.5 decreases by ~10 % summer, but up to 65% in the winter. • Summer: little change in particle acidity. • Winter: much lower particle acidity in Canada, slightly higher in USA. Need to check out winter particle deposition: could be acid particles are depositing sooner in Canada; smaller size due to less NH4.
NAESI Simulations - CMAQ Colin DiCenzo, Roxanne Vinzgaran et al. • Reduce agricultural ammonia emissions in southern British Columbia – what happens? • Determine the extent of ammonia transport across the British Columbia/USA boundary.
NAESI Simulations - CMAQ • Apply CMAQ over small coastal urban region (Lower Fraser Valley; LFV) at 4km, for a number of emission change scenarios. • Use 2000 emissions inventory. • Meteorology: August 2001 and December 2002. • Produce animations of the model results for ozone, PM2.5, ammonia, nitrogen deposition, & sulphur deposition. • Construct time series plots of visibility along 5 lines of sight.
NAESI Simulations - CMAQ • Local emission changes: - 20 to 100% reductions in agricultural ammonia in steps of 20% (5 scenarios) - 100% increase in agricultural ammonia • Trans-boundary Considerations: - all US anthropogenic emissions turned off - all Canadian anthro emissions turned off
NAESI Simulations - CMAQ Example: 60% reduction in ammonia, change in PM2.5
NAESI Simulations - CMAQ • 60% reduction in NH3 required to see a significant reduction in PM2.5 in this region. • NH3 is not a limiting species in the formation of ammonium sulphate/nitrate aerosols in LFV. • Mole ratio analysis in the LFV indicates that reductions of NOx and SOx may be more effective at reducing PM2.5 than NH3 reductions
PrAIRie2005 – Urban AURAMS • Measurement intensive around and over city of Edmonton, late summer 2005. • Edmonton is “interesting”: second highest number of oil and gas processing facilities in a municipal region in North America (1st is Houston), coal-fired power-plants 60 km upwind of city, oil-sands development farther upwind. • AURAMS used in forecast mode during study, and at higher resolution post-processing
PrAIRie2005 • 4 Measurement Platforms, Ground-Based:
PrAIRie2005 • Measurement Platforms, Aircraft: ~100,000 Euro to modify this aircraft and fly 3 weeks
PrAIRie2005 Modelling, post-campaign: • PBL Investigation: compare model results to observations for different PBL approximations, at high and low resolution. • Emissions study: checking database emissions against observed emissions, model predictions, and aircraft concentration observations • Principal component analysis: Comparisons of model results, aircraft observations and analysis to infer sources. All results preliminary!
15 km GEM Output AMPP Interpolation 21 km AURAMS Output 3 km GEM-LAM AMPP Interpolation 3 km AURAMS PrAIRie2005 – Different Resolutions Nesting: • 15 and 2.5 km GEM weather forecast (global/regional and Local Area Model versions), to drive : • 21km and 3 km AURAMS. 6 hourly met analysis (4DVAR)
PrAIRie2005 – Different Resolutions 21km and 3 km AURAMS. 15 minute timestep 2 minute timestep Edmonton
Measured PM1 SO4 (mg/m3), Airborne AMS PrAIRie2005 – Emissions Study Good agreement for timing and location of main features in high res domain. AURAMS-Simulated PM1 SO4 (mg/m3), 3km resolution Images courtesy J. Liggio,EC/ARQP
Fort Saskatchewan Edmonton CRUISER data Courtesy J. Brook Very good agreement for NO, downwind of source region CRUISER
PrAIRie2005 – Different PBL Schemes: weather forecast model modifications Original GEM - Unmodified met model TKE_NEW_R - Met model has heat island added to surface radiative transfer scheme (Makar et al, 2006), and modified TKE formulae for PBL(Han et al 2000). NEWLM - In addition to the TKE_NEW_R changes, a lower limit TKE profile is used (based on Nastrom and Eaton’s observations, 2005). For the high and low resolution runs, how do these sensitivity tests affect model performance both inside and downwind of the city?
PrAIRie2005 – Comparisons with Observations Ground Level O3, downtown Edmonton 21 km AURAMS 3 km AURAMS Peaks tend to be overpredicted. Peaks tend to be underpredicted.
PrAIRie2005 – Comparisons with Observations Ground Level NO, downtown Edmonton 21 km AURAMS 3 km AURAMS Highest amount of Turbulence (pink) gives closest results to obs. (blue) Ditto, but all simulations overpredict NO.
PrAIRie2005 – Comparisons with Observations Ground Level CO, PM2.5, similar behaviour as NO, for downtown Edmonton
PrAIRie2005 – Comparisons with Observations Ground Level NO, 80 km downwind (CRUISER) 21 km AURAMS 3 km AURAMS Clear improvement relative to observations, with the use of the high resolution model
PrAIRie2005 – Comparisons with Observations Ground Level SO2, 80 km downwind 21 km AURAMS 3 km AURAMS Clear improvement relative to observations, with the use of the high resolution model
PrAIRie2005 – Comparisons with Observations Ground Level O3, 80km downwind (CRUISER) 21 km AURAMS 3 km AURAMS Downwind ozone is improved with use of high resolution.
PrAIRie2005 – Comparisons with Observations Ground Level PM1 SO4, 80 km downwind 21 km AURAMS 3 km AURAMS PM1 SO4: Improvement?
PrAIRie2005 – Comparisons with Observations Some conclusions on the resolution issue: Downwind: Increasing resolution improves model results for many species. In urban core: Increasing resolution decreases simulation accuracy. Simple heat island + TKE limits are insufficient to provide the dispersion required to reduce simulated concentrations to match observations.
PrAIRie2005 – Emissions Study Work by post-doc Sunhee Cho: • Studying coal-fired power-plants using AURAMS at high resolution. • Simulations show model overpredicting sulphate relative to airborne AMS observations. • Compared standard emissions input and Continuous Emissions Monitoring – found former was 2x too high, scaled latter. • Compared “before” and “after” scaling simulations against aircraft AMS observations.
PrAIRie2005 – Emissions Study Power-plant Emissions Before, Measured, Scaled: Original Emissions Measured Emissions Scaled Emissions 1000 2000 1000 Average of scaling factors for SO2 and NOx used to scale other emissions
PrAIRie2005 – Emissions Study Effect of Original versus Scaled Emissions: DNOx: max change -30 ppbv DSO2: max change -225 ug/m3 Edmonton city Coal –fired power plants Edmonton city
10 2 PrAIRie2005 – Emissions Study Effect of Original versus Scaled Emissions: Slope and intercept of PM1 SO4 in plume improved. SO2 halved PM1 SO4 better, still high
PrAIRie2005 – Emissions Study Effect of Original versus Scaled Emissions: • The scaled emissions data are better correlated with CEM data and improve model predictions. • Comparison between simulations shows improvements in predicted concentrations near the coal-fired power plants. • Model comparison with observation results show that using scaled emissions has reduced the difference between model and observation data from a factor of 4.6 to 2.3.
PrAIRie2005 – Advanced Data Processing • Work with John Liggio, Shao-Meng Li • Comparison of regional model results, aircraft observations, advanced data processing techniques, to infer sources. • Can different sources be identified? Maybe…
PrAIRie2005 – Advanced Data Processing • John Liggio: using Principal Component Analysis to analyze the airborne aerosol mass spectrometer measurements.
PrAIRie2005 – Advanced Data Processing • John Liggio: using Principal Component Analysis to analyze the airborne aerosol mass spectrometer measurements. • Component 3, afternoon August 27, 2005 flight: This region, where component 3 tracks the total mass well, and accounts for up to 56 percent of the mass, corresponds to the location of the power-plant plume in the high-resolution model run.
PrAIRie2005 – Advanced Data Processing • Work continues on this – may try other forms of analysis as well (PMF, cluster …)