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Transpacific Transport of Ozone Pollution During INTEX-B

Lin Zhang, Daniel J. Jacob, INTEX-B Science Team, TES Science Team

GEOS-Chem User Meeting

Harvard University

Apr 13 2007

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GEOS-Chem simulation

  • V7-04-09 with GEOS-4, 2º x 2.5º
  • Lightning 6 Tg N/yr, regional rescaled with OTD/LIS climatology (Lee Murray)
  • 2004 NOx emission for China (Q. Zhang et al. 2007) (Yuxuan Wang, 65% higher than 2000)
  • Streets et al [2006] CO emission for China increased by 57% (number from B. Pierce/D. Streets at the INTEX-B workshop)

INTEX-B flight tracks

INTEX-B pacific part (Apr 17-May 15, 2006)

  • Characterize ozone production in transpacific plumes.
  • Measurements from M. A. Avery, W. H. Brune, T. Campos, C. A. Cantrell, R. C. Cohen, F. M. Flocke, B. Heikes, G. Huey, L. Mauldin, G. W. Sachse, H. B. Singh, A. J. Weinheimer, and P. O. Wennberg

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MOPITT observed CO column trend over China

Eastern China (20N-50N, 100E-130E)

1.6% relative to 2000

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DC8

C130

CO

NOx

PAN

Ozone

Comparisons of mean vertical profiles of CO, NO2, PAN and ozone

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Ozone production in transpacific plumes

  • Direct ozone transport and ozone produced during transport
  • Transpacific plumes often split into two branches. Ozone production takes place in the south branch.

L

H

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The mean Asian ozone, CO, NOx, and PAN enhancements over the North Pacific at 800 hPa during the INTEX-B period

Latitudinal distribution of NO2 and PAN below 4 km

Conversion from PAN to NOx in the subtropics

Ozone

CO

NOx

PAN

NO2

PAN

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Altitude-longitude section of the Asian ozone enhancement at 30-40N

NA

for the INTEX-B period mean

for the May 5-11 plume

NA

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A

B

Aircraft measured transpacific plume on May 9th

A

B

A-south branch

GEOS-Chem Tropospheric CO Column on May 9

Simulated net ozone production at 680 hPa on May 9

Solid: observations

Dot: GEOS-Chem

B-north branch

PAN

PAN

HNO3

NO

O3

CO

CO

O3

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May 5

May 6

May 7

May 8

May 9

TES observations of the transpacific plume

TES

GEOS-Chem

Tropospheric CO column

GEOS-Chem with TES AK

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TES observed transpacific transport of ozone pollution

TES

GEOS-Chem simulated Asian ozone enhancement

Ozone concentration at 500 hPa

GEOS-Chem

with TES AK

May 5-6

May 7-8

May 9-10

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Measurements by Dan Jaffe at Mt. Bachelor (2.7 km)

Bias = -14 ppbv

R = 0.34

Bias = -1ppbv

R = 0.74

observed CO (139 ± 14)

model CO (125 ± 12)

model Asian CO enhancement (47 ± 7)

observed ozone (54 ± 10)

model ozone (53 ± 8)

Asian Ozone enhancement

(10 ± 2 )

Ozone produced in Asian BL

(4 ± 1.4)

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Back-ups

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Model Ozone at Surface for the INTEX-B period

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MOPITT and AIRS observations of the Asian plume

MOPITT (AM)

AIRS

Total CO column

May 5

May 6

May 7

May 8

May 9