1. Asian outflow and chemical evolution of ozone and nitrogen oxides over the Pacific
Mathew Evans, Daniel Jacob, Harvard Group,
TRACE-P Science Team et al.

2. Questions
How well do we understand the behavior of the O3-HOx-NOx system in Asian outflow?
What is the relative contribution of different sources on O3 and nitrogen oxides in Asian outflow over the Pacific?

3. GEOS CHEM vs observations
Model sampled along flight tracks
Outputs concentrations and rates O3 CO NO
NO2
NOy
PAN
PPN
HNO3 OH
HO2
RO2
H2O2
CH2O
CH3OOH
C2H6
C3H8
Acetone Acetaldehyde
j(O1D)
j(NO2)
H2O
Temp

4. Comparison of model and GOME NO2 preliminary slant column
K Chance, T Kurosu
Smithsonian Astrophysical Observatory
R.V. Martin, P.I. Palmer, Harvard

5. Comparison of model and GOME CH2O preliminary slant column

6. Model and observed O3
West
Mid
North
South
Model / Measurements

7. Model and observed NO
West
Mid
North
South
Model / Measurements

8. Model and observed OH
West
Mid
North
South
Model / Measurements

9. NOy to CO Anthropogenic vs Biomass burning sources
North
South

10. O3 - PAN relationship Model versus observations (color = Latitude)
High latitude
Boundary layer
Low latitude
Free troposphere

11. Impact of anthro. emissions on March NOx Fractional decrease in NOx when anthropogenic emissions are shut off
Fractional decrease in NOx concentration

12. Impact of anthro. emissions on March O3 Decrease in concentration when anthropogenic emissions are shut off
Difference in O3 concentration (ppbv)

13. O3 model / observed ensemble of TRACE-P data and sensitivity simulations

14. Preliminary conclusions
Distribution of NOx observed during TRACEP is consistent with our understanding of combustion sources
Large O3 anthropogenic enhancement in boundary layer Asian outflow with destruction during aging over Pacific.
Free tropospheric O3 in Asian outflow has comparable sources from anthropogenic, biomass burning and lightning
Large model overestimate of HOx and H2O2 and CH2O???
Mystery VOC source over Hainan???