1. Long − Range Transport of Asian Sulfate and Its Effects on the Canadian Sulfate Burden Aaron van Donkelaar, Randall V. Martin – Dalhousie University W. Richard Leaitch, Anne Marie Macdonald – Environment Canada Thomas W. Walker – University of Toronto David G. Streets, Qiang Zhang – Argonne National Laboratory Edward Dunlea, Jose L. Jimenez – University of Colorado Jack E. Dibb – University of New Hampshire Greg Huey, Rodney Weber – Georgia Institute of Technology Meinrat O. Andreae – Max Plank Institute for Chemistry AGU Fall Meeting 2007 December, 14th, 2007

2. INTEX−B Intercontinental Chemical Transport Experiment Phase B NASA driven campaign April-May 2006

3. Sulfate enhancement in free troposphere Organic enhancement in boundary layer Sulfate mass scaled by 1.4 to compensate for size restrictions Trans−Pacific sulfate observed at Whistler? 600 700 800 900 Altitude [km] Pressure [hPa] Aerosol Concentration [µg/m 3 ] 0 3 6 H 2 O Concentration [g H 2 O/kg] 0 1 2 3 43214321 SO 4 = Org NH 3

4. Sulfate contributes to East Asian AOD Model (GEOS-Chem) MODIS MISR MODIS MISR All Dust Model SO 4 = Model held at 2000 anthropogenic emissions

5. Fall AOD trend reflects SO x emissions 6.2 – 9.6% emission growth per year MODIS MISR All Dust Model SO 4 = Model held at 2000 anthropogenic emissions

6. Asian sulfate dominates INTEX−B sulfate Filter Pack 25% higher than unscaled Mist Chamber C130 and Cessna measurements scaled by 1.4 Aircraft Full Emissions No East Asia Model No Anthro.

7. Significant growth to East Asian contribution 2.4-3.4x increase in simulated East Asian contribution since 1985 Aircraft Full Emissions No East Asia Model No Anthro.

8. Long − range transport affects NA sulfate burden April-May 2006 Persistent East Asian contribution at 4 km Near Vancouver: –25-30% of surface sulfate of east Asian origin –40% of sulfate burden (1-5 km) of east Asian origin Altitude [km] SO 4 = at 2.0 km Altitude [km] % Asian SO 4 = SO 4 = [ µ g/m 3 ]

9. Long−range transport degrades surface air quality Mean surface conditions well correlated with simulated East Asian influence during April-May 2006 Mean increase of 0.38 µg/m 3 per +10% Asian influence % Asian (simulated) Measured SO 4 = [ µ g/m 3 ]

10. Conclusions 6.2-9.6% annual mean increase in anthropogenic East Asian SOx emissions since 2000 2.4-3.4x increase in the relative contribution of East Asian sulfate since 1985 Anthropogenic East Asian sulfate degrades NA surface air quality