Transpacific transport of ozone pollution and the effect of recent Asian emission increases on air quality in North America: an integrated analysis using satellite, aircraft, ozonesonde, and surface observations

L. Zhang (1) , D. J. Jacob (1, 2) , K. F. Boersma (2) , D. A. Jaffe (3) , J. R. Olson (4) , K. W. Bowman (5) , J. R. Worden (5) , A. M. Thompson (6) , M. A. Avery (4) , R. C. Cohen (7) , J. E. Dibb (8) , F. M. Flocke (9) , H. E. Fuelberg (10) , L. G. Huey (11) , W. W. Mcmillan (12) , H. B. Singh (13) , A. J. Weinheimer (14)

1 EPS - Department of Earth and Planetary Sciences [Cambridge, USA]
2 SEAS - Harvard John A. Paulson School of Engineering and Applied Sciences
3 University of Washington [Seattle]
4 Atmospheric Sciences Division [Hampton]
5 JPL - Jet Propulsion Laboratory
6 PennState Meteorology Department
7 Department of Chemistry
8 Climate Change Research Center [Durham]
9 EOL - Earth Observing Laboratory [Boulder]
10 FSU | EOAS - Department of Earth, Ocean and Atmospheric Science [Tallahassee]
11 School of Earth and Atmospheric Sciences [Atlanta]
12 Department of Physics [Baltimore]
13 ARC - NASA Ames Research Center
14 NCAR - National Center for Atmospheric Research [Boulder]

We use an ensemble of aircraft, satellite, sonde, and surface observations for April?May 2006 (NASA/INTEX-B aircraft campaign) to better understand the mechanisms for transpacific ozone pollution and its implications for North American air quality. The observations are interpreted with a global 3-D chemical transport model (GEOS-Chem). OMI NO₂ satellite observations constrain Asian anthropogenic NO_x emissions and indicate a factor of 2 increase from 2000 to 2006 in China. Satellite observations of CO from AIRS and TES indicate two major events of Asian transpacific pollution during INTEX-B. Correlation between TES CO and ozone observations shows evidence for transpacific ozone pollution. The semi-permanent Pacific High and Aleutian Low cause splitting of transpacific pollution plumes over the Northeast Pacific. The northern branch circulates around the Aleutian Low and has little impact on North America. The southern branch circulates around the Pacific High and impacts western North America. Both aircraft measurements and model results show sustained ozone production driven by peroxyacetylnitrate (PAN) decomposition in the southern branch, roughly doubling the transpacific influence from ozone produced in the Asian boundary layer. Model simulation of ozone observations at Mt. Bachelor Observatory in Oregon (2.7 km altitude) indicates a mean Asian ozone pollution contribution of 9±3 ppbv to the mean observed concentration of 54 ppbv, reflecting mostly an enhancement in background ozone rather than episodic Asian plumes. Asian pollution enhanced surface ozone concentrations by 5?7 ppbv over western North America in spring 2006. The 2000?2006 rise in Asian anthropogenic emissions increased the influence by 1?2 ppbv.

Domaines: Océan, Atmosphère

L. Zhang, D. J. Jacob, K. F. Boersma, D. A. Jaffe, J. R. Olson, et al.. Transpacific transport of ozone pollution and the effect of recent Asian emission increases on air quality in North America: an integrated analysis using satellite, aircraft, ozonesonde, and surface observations. Atmospheric Chemistry and Physics Discussions, 2008, 8 (2), pp.8143-8191. ⟨hal-00304137⟩