1. INTEX-B flight tracks (April-May 2006)
Recent increases in Asian emissions and consequences for transpacific ozone pollution in the United States: GEOS-Chem model interpretation of Aura and INTEX-B observations
Lin Zhang, Daniel J. Jacob, Kevin W. Bowman, Daniel A. Jaffe, Folkert K. Boersma, Wallace W. McMillan, the INTEX-B and TES science teams
AGU Fall Meeting
(Dec 14, 2007)
INTEX-B flight tracks (April-May 2006)
The rapid industrialization in Asia has raised the issue of how the rising Asian emissions affect the US surface air quality. Here we will talk about transpacific ozone pollution using Aura and INTEX-B observations interpreted with the GEOS-Chem model.
During INTEX-B, we have an integrated aircraft and satellite data set. This gives us a great opportunity to better understand the transport mechanism of transpacific ozone.

2. Asian 2006 NOx emissions constrained from OMI
Asian NOx anthropogenic emissions for the year 2000 from Streets et al. [2003]
2 x 2000 Asian NOx anthropogenic emissions
OMI retrieval from KNMI
OMI NO2 tropospheric column observations demonstrate a factor of 2 increase of Asian anthropogenic NOx emissions from 2000 to 2006.
The factor of 2 increase in East China is consistent with bottom-up estimates from David Streets.
Corrections in Japan and Korea may reflect an underestimation in the prior emissions inventory.
Estimates from David Streets also show Asian NMVOC emissions increased by 45% from 2000 to 2006.

3. Mean ozone and CO concentrations
During INTEX-B (Apr 16 – May ), averaged in 4x5 grid cells
TES
GEOS-Chem with TES AK
GEOS-4, 2 x 2.5 resolution, sampled along TES orbits and applied with TES AK
This gives us confidence in the ozone simulation.
This shows the mean concentrations. Transpacific transport is episodic.
Comparison to aircraft and ozonesondes:
TES
CO: within 5% of DC-8 measurements at 680 hPa (Luo et al. [2007])
Ozone: 3-10 ppbv positive bias compared with sondes (Nassar et al. [2007])
GEOS-Chem
CO: 10% lower than INTEX-B DC-8 and C-130 measurements
Ozone: unbiased compared with aircraft measurements

4. Transpacific transport observed from satellites
TES Ozone
TES CO
AIRS CO
TES CO
AIRS CO
AIRS CO

5. TES and AIRS observations of a transpacific plume
GEOS-Chem
AIRS
CO columns B A

6. Aircraft Measured Transpacific Plume on May 9th
A-north branch
Backward and forward trajectories for the plume A
Solid: observations
Dash: GEOS-Chem
PAN B O3 CO
Simulated net ozone production on May 9 at 680 hPa
B-south branch
PAN A B O3 CO
HNO3 NO
Data from: Henry Fuelburg (trajectory), Melody Avery (O3), Glen Sachse (CO), Hanwant Singh (PAN), Jack Dibb (HNO3), Ron Cohen (NO2), and Greg Huey (NO)

7. Enhanced gross ozone production from Asian emissions at 800 hPa
Ozone production in transpacific plumes
Mean for the INTEX-B period (April 17-May 15, 2006)
Enhanced gross ozone production from Asian emissions at 800 hPa
Differences of gross ozone production rates from the standard simulation and a sensitivity simulation L
Sea level pressure and 800 hPa winds overplotted H
Direct transport of Asian ozone produced in the boundary layer and continuous ozone formation over the Pacific
Splitting of transpacific plumes over the northeast Pacific

8. Latitudinal distribution of NOx and PAN at 1.5 -5 km
Transport of Asian ozone and its precursors
Simulated Asian CO, PAN. ozone, and NOx enhancements at 800 hPa for INTEX-B CO
Ozone
PAN
NOx
Latitudinal distribution of NOx and PAN at km
NOx
PAN

9. Impact of Asian emissions on U.S. surface ozone
Data from Dan Jaffe
O3 measurements at Mt. Bachelor
(44oN, 122oW, 2.7 km, in central Oregon)
Surface O3 enhancements from Asian anthropogenic emissions for INTEX-B
54 ± 10
53 ± 8
9.4 ± 2.5
1 – 5 ppbv
Let me get down to our bottom line. How would transpacific ozone pollution affect the US surface ozone air quality?
rise in Asian emissions has increased U.S. surface ozone
by 1-2 ppbv in the West.

10. Summary
Integrated analysis of satellite, aircraft, ground site observations and a global model to better understand transpacific ozone pollution
OMI Tropospheric NO2 column measurements show nearly a factor of 2 increase in NOx anthropogenic emissions over eastern China from 2000 to 2006.
TES and AIRS observations provide great information on identifying transpacific transport events and their progressions.
Splitting of transpacific plumes often takes place over the northeast Pacific. Ozone production driven by PAN decomposition was observed in the southern branch which affects U.S. air quality.
Asian anthropogenic emissions increase the U.S. surface ozone levels by 5-7 ppbv in the west, and by 9 ppbv at Mountain sites such as MBO. The rise in Asian anthropogenic emissions increased surface ozone by 1-2 ppbv in the western United States, and up to 5 ppbv at MBO.
To summarize: We used the integrated data set of satellite, aircraft and ground site during INTEX-B for better understanding transpacific ozone pollution.

11. Extra

12. Influences of Rising Asian NMVOC Emissions
Changes of NOx, ozone, PAN and HNO3 due to rising Asian NMVOC anthropogenic emissions
Longitude vs. altitude over 30N-45N, April-May 2006
NOx-saturated condition over East China; Formation of PAN over East Asia is sensitive to NMVOCs; PAN decomposition over the North Pacific releases NOx.
The influence of 45% Rise in Asian NMVOC anthropogenic emissions on the US surface ozone is negligible (<0.1 ppbv, and 0.4 ppbv at MBO).

13. Comparisons of Mean Vertical Profiles for INTEX-B

14. Surface Ozone Enhancement from Asian Emissions
for INTEX-B (Apr 16 – May )