1. Long-range Transport of Asian Pollution to North America: Transport, chemistry and variability Qing Liang and Lyatt Jaeglé University of Washington, Seattle

2. Meteorological Indices for Asian Outflow and Transpacific Transport on Daily to Interannual Timescales  Model: GEOS-CHEM Tagged CO simulation 10 year simulation (1992-2002), 2˚x2.5˚ Use seasonal climatological biomass burning and same OH field for each year.  Method Correlate tagged Asian CO tracer with Sea Level Pressure (SLP) to form simple transport indices Liang et al. [2005], submitted to J. Geophys. Res.

3. Daily variability in Asian Outflow Asian Outflow Index: SLP anomalies over NE China  Cyclones over NE China favors export Asian CO R (Asian CO, SLP) R = 0.38-0.47 SLP anti-correlated with export 1993

4. Daily variability in transpacific transport Transpacific Transport index: SLP anomalies in E. Pacific  Strong Pacific High favors transpacific transport Asian CO R (Asian CO, SLP) R = 0.27-0.53 SLP correlated with transport 1993

5. Interannual variability of Transpacific Transport R = 0.65 Enhanced Transpacific Transport Monthly Asian CO in the western North America is correlated with the meridional SLP gradient Index: Weighted SLP anomalies over the N. Pacific Winter & Spring

6. What drives the interannual variability of transpacific transport?  LRT3 strongly projects on Pacific and North American (PNA) index R(LRT3, PNA)=0.69 for 1948-2004 Enhanced Transpacific Transport

7. Summertime influence of Asian pollution in the middle and upper troposphere during INTEX-A  INTEX-A: 18 flights, Jun. 29 – Aug. 14, 2004  Goals and Methods What was the extent of Asian influence over the U.S. during INTEX-A? Use GEOS-CHEM to identify Asian plumes in observations, characterize their composition, and elucidate their chemical evolution and transport mechanisms Asian plumes sampled during INTEX-A (Modeled Asian CO > 25-30 ppbv) 6 Asian plumes Asian CO GEOS-CHEM Model Observ.

8. Chemical Composition of Asian Plumes Observed Δ Model Δ CO, ppbv +19+6 O 3, ppbv +23+13 HNO 3, pptv -8+20 PAN, pptv +97+4 Acetylene, pptv +47 Enhancement in Asian Plumes vs. Background Modeled Asian CO [ppbv] Asian Plume DIAL+ In Situ O 3 Observations [ppbv] 12 3 July 1, 2004 – Asian Plume 1 2 3

9. Future work  Chemical properties and evolution of the Asian plumes  Origin of discrepancy between model and observations (transport, STE, chemistry?)  Impact on Ozone in UT over US  Was transpacific transport during INTEX-A unusual?