SATELLITE OBSERVATIONS OF OZONE SATELLITE OBSERVATIONS OF OZONE PRECURSORS FROM GOMEPRECURSORS FROM GOME

Randall Martin, Daniel Jacob,Paul Palmer, Qinbin Li

Harvard University Kelly Chance, Thomas Kurosu

Harvard-Smithsonian Center for Astrophysics

SURFACE OZONE ENHANCEMENTS CAUSED BY SURFACE OZONE ENHANCEMENTS CAUSED BY ANTHROPOGENIC EMISSIONS FROM DIFFERENT CONTINENTS ANTHROPOGENIC EMISSIONS FROM DIFFERENT CONTINENTS

GEOS-CHEM model July 1997

North America

Europe

Asia

Li et al. [2002]

THE GOME SATELLITE INSTRUMENTTHE GOME SATELLITE INSTRUMENT

•Launched in April 1995

•Nadir-viewing solar backscatter instrument (237-794 nm)

• Low-elevation polar sun-synchronous orbit, 10:30 a.m. observation time

• Field of view 320x40 km2, three cross-track scenes

• Complete global coverage in 3 days

USE GOME MEASUREMENTS OF NOUSE GOME MEASUREMENTS OF NO22 AND HCHO COLUMNS AND HCHO COLUMNS

TO MAP NOTO MAP NOx x AND VOC EMISSIONSAND VOC EMISSIONS

Emission

NO NO2

HNO3

lifetime <1 day

NITROGEN OXIDES (NOx) VOLATILE ORGANIC CARBON (VOC)

Emission

VOC

OHHCHO hours

CO

hours

BOUNDARYLAYER

GOME

NO/NO2

W ALTITUDE

RETRIEVAL OF TROPOSPHERIC NORETRIEVAL OF TROPOSPHERIC NO2 2 FROM GOME FROM GOME (errors (errors in 10in 101515 molecules cm molecules cm-2-2))

GOME SPECTRUM (423-451 nm)

SLANT NO2 COLUMN

TROPOSPHERIC SLANT NO2 COLUMN

TROPOSPHERIC NO2 COLUMN

Fit spectrum

Remove stratospheric contribution, diffuser plate artifact

Use Central Pacific GOME data with:•HALOE to test strat zonal invariance•PEM-Tropics, GEOS-CHEM 3-D model to treat tropospheric residual

Apply AMF to convert slant column to vertical column

Use radiative transfer model with:•local surface albedos from GOME •local vertical shape factors from GEOS-CHEM• local cloud info from GOMECAT

O3, O4, H2O, Ring

Quantitative retrieval for partly cloudy scenes

CAN WE USE GOME TO ESTIMATE NOCAN WE USE GOME TO ESTIMATE NOx x EMISSIONS?EMISSIONS?TEST IN U.S. WHERE GOOD TEST IN U.S. WHERE GOOD A PRIORI A PRIORI EXISTS EXISTS

Comparison of GOME retrieval (July 1996) to GEOS-CHEM model fieldsusing EPA emission inventory for NOx

GOME

GEOS-CHEM(EPA emissions) NO/NO2

WITH ALTITUDE

NOx lifetime <1day

BIAS = +18%r = 0.78

GOME RETRIEVAL OF TROPOSPHERIC NOGOME RETRIEVAL OF TROPOSPHERIC NO22

vs. GEOS-CHEM SIMULATION (July 1996)vs. GEOS-CHEM SIMULATION (July 1996)

GEIA & Loganemissionsscaled to 1996

[1016molec cm-2]

GEOS-CHEM GOME

ISOPRENE MAIN SOURCE OF HCHO IN U.S. IN SUMMERISOPRENE MAIN SOURCE OF HCHO IN U.S. IN SUMMER HCHO columns – July 1996HCHO columns – July 1996

r2 = 0.7

Bias = 11%

Model:Observed HCHO columns

GEIA isoprene emissions

[1012 atoms C cm-2 s-1]

Palmer et al.

GEOS-CHEM RELATIONSHIP BETWEEN HCHO COLUMNS GEOS-CHEM RELATIONSHIP BETWEEN HCHO COLUMNS AND ISOPRENE EMISSIONS IN N AMERICAAND ISOPRENE EMISSIONS IN N AMERICA

Use relationship to map isoprene emissions from GOME observationsUse relationship to map isoprene emissions from GOME observations

Palmer et al. [2002]

GEOS-CHEMJuly 1996

NW NE

SESW

Isoprene emission [1013 atomC cm-2 s-1]

model without isoprene

Mod

el H

CH

O c

olu

mn

[101

6 m

ole

c c

m-2

]

ISOPRENE EMISSIONS FOR ISOPRENE EMISSIONS FOR JULY 1996 DETERMINED BY JULY 1996 DETERMINED BY SCALING OF GOME SCALING OF GOME FORMALDEHYDE COLUMNS FORMALDEHYDE COLUMNS [Palmer et al., 2002][Palmer et al., 2002]

GOME

CONSISTENT WITH IN-SITU HCHO OBSERVATIONSGEIA

r2 = 0.53

Bias -3%

GOMEr2 = 0.77

Bias -12%

GOME TROPOSPHERIC SLANT COLUMNS GOME TROPOSPHERIC SLANT COLUMNS DURING TRACE-P (3/15 - 4/15, 2001)DURING TRACE-P (3/15 - 4/15, 2001)

NO2 HCHO

NEXT STEP: COUPLED CHEMISTRY-AEROSOL MODELNEXT STEP: COUPLED CHEMISTRY-AEROSOL MODELRadiative and chemical (uptake HORadiative and chemical (uptake HO22, NO, NO22, NO, NO33) effects of ) effects of

aerosols (SOaerosols (SO44, BC, OC, Dust, Sea-Salt) , BC, OC, Dust, Sea-Salt)

Off-line aerosol fields from Ginoux et al. [2001] and Chin et al. [2002]

GEOS-CHEM March OH

O3

AEROSOLS REDUCE SURFACE OAEROSOLS REDUCE SURFACE O33 AND OH AND OH

GEOS-CHEM August OH

O3

Off-line aerosol fields from Ginoux et al. [2001] and Chin et al. [2002]

CONCLUSIONSCONCLUSIONS

OH and O3 from Aerosols

Isoprene from GOME

NOx from GOME

Intercontinental O3 transport