VALIDATION OF OMI TROPOSPHERIC NOVALIDATION OF OMI TROPOSPHERIC NO22 DURING INTEX-B DURING INTEX-B

AND APPLICATION TO CONSTRAIN NOAND APPLICATION TO CONSTRAIN NOxx EMISSIONS EMISSIONS

IN THE EASTERN UNITED STATES AND MEXICOIN THE EASTERN UNITED STATES AND MEXICO

K. F. Boersma, D. J. Jacob, E.J. Bucsela, A.E. Perring, R. Dirksen, R.J. van der A, R.M. Yantosca, R.J. Park, M.O. Wening, T.H, Bertram,

R.C. Cohen

OMI NO2 VALIDATION DURING INTEX-B AIRCRAFT CAMPAIGN

21 DC-8 validation spirals(open circles)

Mean OMI tropospheric NO2 (March 2006 - KNMI near-real-time product v0.8)

Spiral 2 (up)

OMI VALIDATION SPIRAL IN INTEX-BOMI VALIDATION SPIRAL IN INTEX-B

NO2 (ppbv)

Spiral 1 (down)

DC-8 floor is 1000 ft. over land, 500 ft. over ocean: must extrapolate to surface for comparison to OMI tropospheric column

Pre

ssu

re (

hP

a)

1000

200

0 2

In situ data fromU.C .Berkeley(Ron Cohen)

OMI VALIDATION STATISTICS IN INTEX-BOMI VALIDATION STATISTICS IN INTEX-B

Mexico City points: large extrapolationto the ground Is required

• Subset with extrapolated fraction < 30% yields slope = 0.99 ± 0.17 (r2 = 0.67, n = 12)• Ocean subset indicates OMI negative bias = - 0.6x1015 molecules cm-2, fitting error 0.5x1015 molecules cm-2

CONTINUITY FROM SCIAMACHY TO OMICONTINUITY FROM SCIAMACHY TO OMIDifferences between OMI (13:30) and SCIAMACHY (10:00) can be explained by diurnal variation in NOx emissions and chemistry [Boersma et al., 2007]

Mean August 2006 data

CONSTRAINING NOCONSTRAINING NOx x EMISSIONS IN EASTERN U.S. FOR MARCH 2006EMISSIONS IN EASTERN U.S. FOR MARCH 2006

Bottom-up: EPA NEI99 for March OMI with NO2/ENOx from GEOS-Chem

Adjust NEI 99 data to match OMI for different NOx emission categories:

• Power plants, industry 25%• On-road vehicles 30%• Off-road vehicles 9%•TOTAL ANTHROPOGENIC 3% Resulting fit r2 = 0.87

Error ± 25%

Could rising vehicular emissions counter benefit of power plant reductions?

CONSTRAINING NOCONSTRAINING NOxx EMISSIONS IN MEXICO EMISSIONS IN MEXICO Bottom-up: BRAVO in N. Mexico,

GEIA elsewhere, 20% soil contribution OMI with NO2/ENOx from GEOS-Chem

• Bottom-up inventory too low by factor of 2.0

• Mexico City: likely due to fires

• Elsewhere: likely due to soil emissions

TOWARD BETTER UNDERSTANDING OF THE MIDDLE EAST TOWARD BETTER UNDERSTANDING OF THE MIDDLE EAST OZONE MAXIMUMOZONE MAXIMUM

Zhang et al. [2006]

averagingkernels

(July 2005)

TES observations for July 2005 reprocessed with uniform a priori

OMI TROPOSPHERIC NOOMI TROPOSPHERIC NO22 DATA OVER MIDDLE EAST DATA OVER MIDDLE EAST

Comparison with bottom-up estimate (GEIA) indicates large underestimatesof NOx emissions in Iran and Saudi Arabia

OMI EVALUATION WITH URBAN NOOMI EVALUATION WITH URBAN NO22 DATA IN ISRAEL DATA IN ISRAEL

Tro

po

sph

eric

NO

2 co

lum

n,

1015

cm

-2

Carmiel

Beer Sheva

OMIin situ

Seasonal variation for 2006; in situ surface dataextrapolated through local boundary layer depth

with Y. Rudich and M. Trainic (Weizmann)

COMPARISON OF OMI AND SCIAMACHY WITH NOCOMPARISON OF OMI AND SCIAMACHY WITH NO22 DATA DATA

AT ALL ISRAEL STATIONSAT ALL ISRAEL STATIONS

SCIAMACHY (10:00 local) OMI (13:30 local)

r = 0.55 (n=136)

RMA: y = 0.19 + 0.97x

r = 0.61 (n=396)

RMA: y = -1.28 + 0.90x