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AURAMS Simulations of Pacific2001

AURAMS Simulations of Pacific2001. Paul Makar , V.S. Bouchet, W. Gong, M. D. Moran, S. Gong, A.P. Dastoor,   K. Hayden, H. Boudries, J. Brook, K. Strawbridge, K. Anlauf, S.M. Li. Air Quality Research Branch Meteorological Service of Canada. Main ground sites and flow patterns.

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AURAMS Simulations of Pacific2001

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  1. AURAMS Simulations of Pacific2001 Paul Makar , V.S. Bouchet, W. Gong, M. D. Moran, S. Gong, A.P. Dastoor,  K. Hayden, H. Boudries, J. Brook, K. Strawbridge, K. Anlauf, S.M. Li. Air Quality Research Branch Meteorological Service of Canada

  2. Main ground sites and flow patterns Shao-Meng Li, PI (shao-meng.li@ec.gc.ca) PACIFIC2001: An overview A measurement intensive on Canada’s West Coast, August 2001

  3. Scientific Questions of Pacific 2001 • Chemical and physical properties of fine PM in haze • Horizontal and vertical distributions of fine PM and O3 • Identification of the transition zone between emission • and formation controlled regimes. Fraction of fine PM • in road dust • Physical/chemical characteristics of PM, and variation • in the Lower Fraser Valley • Major processes in SOA and ozone formation and the • relative role of biogenic vs. anthropogenic emissions • for SOA and O3 • Significance of NH3 to fine PM formation and its major • sources • Emissions from light duty transportation sector • PM formation and evolution processes

  4. Participants • Universities: 13 in Canada, US, UK, • Agencies: 11 partners in federal, provincial, municipal, • and private sector agencies • Scientists and Support Staff: >140 • Coordination with the PNW2001 • Main ground sites and missions Cassiar Tunnel: Emissions from transportation sector Slocan Park:Urban pollution mix Langley Ecole Lochiel: Suburban/rural setting Sumas Eagle Ridge: Urban/biogenic mix and visibility Golden Ears Park: Biogenic impacts on PM Others: Port Coquitlam (Slope Study), Langley Poppy High School,Upper Air Sites, Burnaby South High School, GVRD Network

  5. Model/Measurement comparisons: Monitoring Networks versus Measurement Intensives • Two types of data for comparisons: • Monitoring Networks: • Multiple locations across a wide spatial domain. • Long time periods available. • Limited chemical speciation • Limited time intervals (and 24 hr averages) • Measurement Intensives – like Pacific 2001: • Highly speciated • High time-resolution • Data only available at small number of sites. • Measurements are for a limited total time.

  6. AURAMS Western Domain 148 x 124 gridpoints in horizontal (21km resolution) 28 vertical levels (top at 30 km, hybrid coordinates: terrain following at ground, pressure at top) Detailed measurements, but not great spatial coverage.

  7. AURAMS Western Domain Monitoring Networks: better spatial coverage (though measurements are 24 hr averages and may be infrequent)

  8. Monitoring Networks used for Pacific 2001 CAPMoN is the Canadian air and precipitation monitoring network, IMPROVE the interagency monitoring network of protected visual environment, NAPS the (Canadian) national air pollution surveillance network, and AIRS the US EPA Aerometric Information Retrieval System. Data provided by Julie Narayan & Bob Vet, Natchem Database

  9. Monitoring Networks Note: Red stations are less than 250 km from the coast . Blue stations > 250 km from coast. PM2.5 Sulphate “Good” PM2.5 Nitrate “over-predicted” near coast and inland. PMtotal Sulphate “Low, high scatter” PMtotal Ammonium “Good” PMtotal Nitrate: “Good” PM2.5 EC: “Inland under-prediction, Coastal over-prediction.”

  10. Monitoring Networks Some that aren’t so good (poor correlation): PM2.5 OC: ok near coast, but underpredicted at some points inland. PM2.5 Sea-Salt: neither over nor underpredicted. Poor correlation PMtotal Sea-Salt: overpredicted, but correlation higher (0.489). PM2.5 Crustal Material: large overprediction (but obs. don’t include all cations).

  11. Overall: p-SO4, p-NH4 best, p-NO3 high, p-OC and p-EC low Sea-Salt and Crustal Material high. Note that inorganic component correlations and slopes are significantly better than one year ago! • Better mass conservation, and Crank-Nicholson vertical diffusion main causes of improvements. But…why is the p-NO3 high? The measurement intensive data was used to analyze this problem:

  12. (TEOM@30C+SES measurements) PM2.5 Concentration (mg m-3) PST Compare the total mass of PM2.5, model vs measurement, Langley (downwind rural site impacted by urban plume). 20 Last three days: model over-predicts total particle mass, relative to measurements. 20 TEOM data courtesy Jeff Brook.

  13. Look at model particle composition predicted: 58% of particle mass during the last 3 days is PM2.5 nitrate (red): PM2.5 NO3

  14. Particle size and Speciation: A look at the AMS results. p-NO3: AMS data courtesy Hacene Boudries, Aerodyne. Model size range ok, but magnitudes are higher than the measurements. What about p-NH4? NH3 required for fine mode p-NO3 formation, so would expect this to be high, too.

  15. Particle size and Speciation: A look at the AMS results. p-NH4: AMS data courtesy Hacene Boudries, Aerodyne. p-NH4 is high relative to the measurements, too, in the last three days of the simulation. Ok before.

  16. What is the source of the p-NO3? HNO3 (g), of course…

  17. What is the source of the HNO3? NOx, of course…

  18. And the source of p-NH4 is NH3 gas… also being over- predicted. Denuder data courtesy Katherine Hayden

  19. The precursor gases for particle nitrate formation are too high. At a downwind site, its difficult to determine the cause of the problem (too many possible causes). Right in the middle of the city, there’s not enough time for much chemical processing (eliminates the chemistry). So…what’s up in Slocan Park (downtown site)?

  20. Close to the urban core, the NOy (mostly NOx) are maximizing in the same double peak at night as the obs., Right timing, but the maxima are about 10x too high. NOy data courtesy K. Hayden  No time for HNO3 formation: emissions or transport are the cause of the over-prediction.

  21. Emissions: compared Vancouver NOx AURAMS totals to more recent emissions data: only 17% difference in diurnal totals.  It’s not the emissions. Transport: Advection and vertical diffusion. Advection not too bad… varies…

  22. NO Emissions Comparison: CEPS 1990 vs SMOKE 2000 (Dave Fox) 40,62 35,57 159 Tonnes/day 132 Tonnes/day CEPS resolution 21x21 km; SMOKE resolution 36x36 km

  23. Advection: Coastal stations: Some good and some not… Problem with wind velocity under-prediction at Sand Heads; others ok. Wind data courtesy Brad Snyder

  24. Vertical Diffusion: compare ground based LIDAR estimates of PBL height to model values at Langley (K. Strawbridge et al): something interesting happens at night: Nighttime PBL height is being greatly under- estimated. This can have a huge impact on concentrations.

  25. Alternative boundary layer parameterizations being investigated. 23:00 Z, August 27th 15:00 PDT, August 27th 03:00 Z, August 28th 19:00 PDT, August 27th 22:00 Z, August 27th 14:00 PDT, August 27th 04:00 Z, August 28th 20:00 PDT, August 27th 00:00 Z, August 28th 16:00 PDT, August 27th 19:00 Z, August 28th 11:00 PDT, August 28th 00:00 Z, August 29th 16:00 PDT, August 28th 18:00 Z, August 28th 10:00 PDT, August 28th 17:00 Z, August 28th 09:00 PDT, August 28th 16:00 Z, August 28th 08:00 PDT, August 28th 09:00 Z, August 28th 01:00 PDT, August 28th 11:00 Z, August 28th 03:00 PDT, August 28th 14:00 Z, August 28th 06:00 PDT, August 28th 01:00 Z, August 28th 17:00 PDT, August 27th 15:00 Z, August 28th 07:00 PDT, August 28th 22:00 Z, August 28th 14:00 PDT, August 28th 23:00 Z, August 28th 15:00 PDT, August 28th 20:00 Z, August 28th 12:00 PDT, August 28th 05:00 Z, August 28th 21:00 PDT, August 27th 13:00 Z, August 28th 05:00 PDT, August 28th 02:00 Z, August 27th 18:00 PDT, August 27th 21:00 Z, August 28th 13:00 PDT, August 28th 08:00 Z, August 28th 00:00 PDT, August 28th 06:00 Z, August 28th 22:00 PDT, August 27th 21:00 Z, August 27th 13:00 PDT, August 27th 20:00 Z, August 27th 12:00 PDT, August 27th 18:00 Z, August 27th 10:00 PDT, August 27th 10:00 Z, August 28th 02:00 PDT, August 28th 19:00 Z, August 27th 11:00 PDT, August 27th 12:00 Z, August 28th 04:00 PDT, August 28th 07:00 Z, August 28th 23:00 PDT, August 27th Example: Difference in PBL height, two parameterizations.

  26. Conclusions: • AURAMS doing fine for p-SO4, total p-NH4 over grid. • (2) PM2.5 p-NO3 over-predictions over grid.  Analysis of • PM2.5 p-NO3, p-NH4, NH3 over-predictions in LFV. • (3) Detailed analysis suggests model predicted PBL • is too low. Working on improvements to GEM for this. • (4) Next steps: comparing to GEM-LAM • (2.5 km resolution) runs.

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