K. Baumann, M.H. Bergin, W.L. Chameides, F. Ift, C.S. Kiang, J.Z. Zhao

1. Fine Particle (PM2.5) Composition and Trace Gas Measurements in the Yangtze Delta RegionIn memoriam Dr. Glen Cass K. Baumann, M.H. Bergin, W.L. Chameides, F. Ift, C.S. Kiang, J.Z. Zhao School of Earth and Atmospheric Sciences, Georgia Institute of Technology, Atlanta K.S. Shao, X.Y. Tang, M.L. Wang, L.M. Zeng Center for Environmental Sciences, Peking University, Beijing • Locations, tools, and data quality • Meteorological and trace gas characteristics at SheShan • Spatial trends in PM2.5 mass and composition • Seasonal comparison based on ChangShu data

2. Sampling Locations in the Yangtze Delta

3. Sampling Locations in the Yangtze Delta SheShan LinAn

4. Continuous Trace Gas Measurements SheShan Nov-99 intensive NO/NOy Yangtse network station set-up The inlet box, mounted on the roof of the SheShan observatory, allowed standard addition of NO, and NO2 (via GPT) calibration gases. A single chemiluminescence detector was utilized, alternating between NO and NOy measure modes every 2 min with instrument zeroes overlapping every 15 min. The flow controller stream selector valve assembly was housed inside resulting in a sample residence time of ~7 s. The NOy converter is a 35 cm long, 0.48 cm ID MoO tube, temperature controlled at 330 ±2 oC. All air intake surfaces were Teflon coated and T-controlled at 40 oC.

5. Discrete PMfine Measurements via Particle Composition Monitor (PCM)

6. PCM Data Quality

7. Trace Gas Data Quality Note: values for NO/NOy are from GIT’s research grade analyzer, and uncertainty in NOy arises from MoO conversion efficiency determined for NO2 Q(NO2) = 67 ±14 %.

8. Average PM2.5 and PM10 Concentrationsfor SheShan November 99 ± 1-sigma Major ions represented mainly in fine fraction; bulk of sodium and calcium in coarse fraction

9. SheShan November 99Correlations with Wind, Wind Roses NOy indicative of influence from mobile sources, i.e. the Shanghai-Hangzhou Expressway to S and E, and metropolitan Shanghai to NE SO2 points to possible point sources to W and NE

10. SheShan November 99Meteorological, Trace Gas, and [PM2.5] Time Series

11. SheShan PM2.5 and Met. Data November 99 • Change in synoptic conditions on 11/14 and 11/23 (cold fronts) • accompanied by sharp drops in PM2.5 and O3, subsequent recovery • High mass on 11/24 due to agricultural burning in close vicinity to the site

12. Sampling Locations in the Yangtze Delta

13. Regional Comparison of PM2.5 Composition • Lowest levels at LinAn background station, • but temporal fluctuations similar to ChangShu • Regional influence by cold front passages (11/14 and 11/23) noticeable at both sites • Signatures of sporadic local influences on top of regional trend

14. Average Mass Composition No significant regional differences in November 99, but noticeable seasonal differences at ChangShu

15. Seasonal/Regional Averages • Seasonal differences in K+ due to post-harvest biomass burning activities in November • ChangShu highest Na+, Cl-, suggesting maritime influence • Aerosol slightly acidic regionally; but lower variability at LinAn

16. Comparison with Seasonal/Regional Averages at U.S. Sites ATL: Atlanta, GA – urban HV: H’ville, TN – suburban DX: Dickson, TN - rural • Significantly lower [PM2.5] at U.S. sites, even during • summer • [O3] comparable • in fall, much higher • in summer, esp. • in urban Atlanta • Slightly alkaline aerosol • in fall and winter, • as opposed to Yangtze sites, • probably due to different • emission patterns

17. Summary • NH4+, SO42-, NO3-, and oxalate predominantly in fine mode (PM2.5); alkaline, alkaline earth cations, Cl- and acetate represented indifferently between fine and coarse (PM10) modes • Despite low photochemical activity during November period, O3 buildup along with PM2.5 concentrations after frontal passage • During this buildup period, close correlation of gas phase SO2 and particle phase SO42- observed • Apparent influence from roadways and point sources at SheShan indicated by NOy and SO2 • Average PM2.5 mass concentration levels highest at ChangShu, possibly due to close vicinity of traffic sources; lowest in LinAn (background site) • No regional differences in fine particle composition, but noticeable seasonal differences, especially with respect to carbonaceous species and sulfate • Seasonal differences most noticeable in K+ indicating influence of post-harvest burning in November • Significantly (~3x) lower PM2.5 in SE-US with tendency to slightly alcalinic aerosol in fall and winter compared to slightly acidic conditions in the Yangtze Delta region

18. Acknowledgements • Prof. Du HuiFang, Fudan University, ShangHai, for invaluable help preparing and organizing the November intensive at SheShan • Ms. Wu LiBo, Fudan University, ShangHai, for indispensable help and support at the SheShan site • Prof. Ding Guoan, CAMS Beijing, for patient help clearing research equipment with Chinese customs • The various local site operators at ChangShu, LinAn and SheShan for their diligence and willingness to help us out with anything, anytime!!

19. SheShan November 99Diurnal Trends Related to Air Mass Transport Symbol code: Size=WS / color=WD • Winds driven by synoptic forces rather than convective (no diurnal trend) • Strong winds carry background [O3] ~30-40 ppbv • NO peaks in morning and high levels carried into evening • Weak photochemistry indicated by O3 and NO/NOy

20. PCM/Andersen Comparison SheShan 11/99 - Teflon

21. PCM/Andersen Comparison SheShan 11/99 – Quartz