1. Response of fine particles to the reduction of precursor emissions in Yangtze River Delta (YRD), China Juan Li 1, Joshua S. Fu 1, Yang Gao 1, Yun-Fat Lam 1 Guoshun Zhuang 2, Kan Huang 1,2, Ying Zhou 3 1. The University of Tennessee, Knoxville, U.S.A. 2. Fudan University, China 3. Emory University, U.S.A. 9 th Annual CMAS Conference, October 11-13, 2010 Chapel Hill, NC

2. Outline Introduction Objective Model description and performance Sensitivity study VOC emission reduction NOx emission reduction Implication on emission control in YRD

3. Shanghai City Population: 18,884,600 Population Density: 2,700 inhabitants/km² Yangtze River Delta Area: 99600 km 2 Population: over 80 million people in 2007 50 million are urban. Introduction

4. Current issue (O 3 & PM) Haze Shanghai True color-satellite image on January 18, 2007 YRD is one of the four regions in China, which experiences severe visibility impairment. (Record: PM 10 = 512  g/m 3 ) However, very limited regional modeling have been performed in YRD.

5. Objective  To study the response of O 3 and PM 2.5 over YRD to the changes of NOx and VOC emissions using CMAQ.  Reveal the atmospheric nitrate chemistry over YRD to provide effective suggestions about emission control.

6. Modeling Configuration 27 km 9 km 3 km CMAQ V4.6 with CB05AE4 Meteorological Input: MM5 V3.7 Domain: 27km, 9km & 3km Vertical Grid Spacing: 24 layers Emission: INTEX-B with local emission adjustments Simulation Period: 2006 IC/BC: GEOS-Chem Discussion will be mainly on 3 km domain

7. Emissions Development Regional Emission Inventory –INTEX-B & TRACE-P GIS program –Spatial Allocation –Spatial Allocation Factor FORTRAN Program –Emission Vertical distribution –Temporal Allocation Domain Regional Re-adjustment of Emissions Area

8. INTEX-BVOC43.56 RefVOC57.42 INTEX-BNOX50.06 RefNOX46.39 Unit: 1000 tons/year Emissions Comparison INTEX-B: Intercontinental Chemical Transport Experiment- Phase B Ref. Local report

9. Emissions Comparison (Cont.)

10. Examples of CMAQ Emissions Input MethanolPNO3 g/smole/s

11. MM5 Wind and Temperature Dec. 2006, Shanghai Jul. 2006, Shanghai

12. JULY Wind rose plot in Shanghai JANUARY

13. CMAQ scenarios ScenarioSectorDescriptionReduction Pct 0BaseBase case- 1PowerNOx alone (SCR alone)~85% 2PowerNOx + SO 2 (SCR + FGD)~85% for NOx + ~90% for SO2 3TrafficNOx alone20% 4TrafficNOx + VOC20% 5TrafficNOx + VOC + PM20% 6TrafficNOx + VOC + PM50%, sensitivity run 7TrafficVOC alone20% 8industryNOx alone20% 9industryNOx + any important co-pollutants20% 10combinedAdditional sensitivity runs

14. Observational Site Red color: A represent O 3 observational site; Blue color: B represent PM 2.5 NH 4 +, NO 3 - observational site Observational site locate in Fudan University, a representative of residence area in downtown of Shanghai

15. Ozone Time Series in Site A MBNMBNMEMNB a MNE a R RMS E Daily_max_ 8hr Ozone-6.4-14.0%24.7%-4.3%28.1%0.816.7 Hourly Ozone 60 b -2.2-25.7%29.0% - 25.3 %28.9%0.627.5 Ozone performance statistics (based on 4 months of data)

16. PM 2.5 Daily Average Distribution MBNMBNMEMNB a MNE a RRMSE Daily_24hr Avg-6.10.1%44.53%0.5%47.2%0.4321.67 PM 2.5 performance statistics (based on 4 months of data)

17. Model Performance - Temporal Distribution

18. Model Performance - Statistics NMB—the normalized mean bias; NME—the normalized mean error; VariableData #Mean Obs.Mean SimulationNMBNME SO 2 (ppb)36545.1350.1411.1%42.7% NO 2 (ppb)36535.9142.2217.6%37.5% O 3 (ppb)16630.5527.15-11.1%37.2% NH 4 (μg/m 3 )992.833.5224.5%71% NO 3 (μg/m 3 )992.211.87-15.7%77.8% PM 10 (μg/m 3 )36566.6271.136.8%40.7%

19. Sensitivity Study Response of PM 2.5 to 20% reduction of NOx and VOC, respectively

20. Response of NH 4 +, NO 3 - to the reduction in 20% NOx and 20% VOC emission Reduction in 20%VOCReduction in 20%NOx

21. Correlation between PAN and NH 4 +, NO 3 - PAN were well correlated with NH 4 + and NO 3 - ; the slopes in four seasons were in the order of winter>fall>spring>summer, which was coincident with the seasonal variation of temperature, indicating that lower temperature is in favor of the formation of PAN, Peroxyacetyl nitrate (PAN) may play a key role in the formation of NO 3 - and NH 4 + in response to the reduction of NOx emission.

22. PAN (Peroxyacetyl nitrate) CH 3 C(O)OO · + NO 2 CH 3 C(O)OONO 2 (PAN) HNO 3 + NH 3 NH 4 NO 3

23. Response of O 3 to reduction in NOx and VOC emission by 20% Reduction in 20%NOxReduction in 20%VOC

24. Response at Other Sites Reduction in 20%VOCReduction in 20%NOx

25.  PAN may play a key role in the formation of NO 3 - and NH 4 + in response to the reduction of NOx emission.  Emission reduction of VOC in YRD is more effective than NOx in terms of reducing O 3 and PM 2.5. Summary

26. Acknowledgement  Energy Foundation  Harvard School of Public Health (Grant No. G-0910-10653).  National Key Project of Basic Research of China (Grant No. 2006CB403704),  National Natural Science Foundation of China (Grant Nos. 20877020, 40575062, and 40599420).  The National Institute for Computational Sciences at the University of Tennessee provides CPU time on the Kraken supercomputer to conduct the simulations.

27. Question