CO as a Precursor of Ozone and a Tracer of Transport: Evidence from

MOPITT Data

J. Kar (UT), H. Bremer (UB), James R. Drummond (UT), F. Nichitiu (UT), J. Zou (UT), J. Liu (UT), Y. Rochon

(MSC), J. C. Gille (NCAR), M. N. Deeter(NCAR), G. Francis (NCAR), D.

Ziskin (NCAR), J. Warner (NCAR)

Carbon Monoxide (CO)

Sink of OH Precursor of Ozone

Tracer of Transport ( ~ few mths)

Use MOPITT CO data to address:

• Correlation between CO and O3 in the context of biomass burning in the tropics (Delineate the causes of ozone variation)

• Signature of transport phenomena (Convection, STE?!)

• MOPITT measures upwelling radiation by gas correlation radiometry in thermal IR near 4.7 m and reflected solar radiation near 2.3 m

• CO mixing ratio profiles and total columns are retrieved by Optimal Estimation Technique. Mixing ratios reported at surface, 850, 700,500,350,250,150 hPa

• a Priori Single and constant over time (variations in retrievals reflect geophysical variations).

• Retrievals on different levels are not independent Averaging Kernel (Vertical resolution)

• Validation of MOPITT data– MOPITT CO biased by < 8%

MOPITT CO and SHADOZ Ozone Profiles at Natal

Comparison of MOPITT CO and MODIS Aerosols

Comparison of MOPITT CO and SHADOZ Ozone

Bremer et al.,2004JGR (In press)

Fire Data From ATSR for MAM, 2001

Courtesy: Sam Oltmans

10 Year Climatology of 10 day Back Trajectories

Convection Signature in MOPITT CO Data Near Calcutta(22.3N, 88.2E)

Back Trajectories, OLR and SST Indicate Convective Activity

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x

x

x

x

30-50

CO m.r.(ppbv)

Pre

ssur

e(hP

a)Locations of CO Profiles with Possible Signature of

Convection(2002)

STE as seen in MOPITT CO Data near Wallops Island (37.8N, 75.5W)

Conclusions:• Distinct seasonal patterns of CO at several SHADOZ stations indicate strong influence of African and South American biomass burning.

• Enhanced CO columns are consistent with corresponding enhancement in tropospheric ozone content from sonde data except at San Cristobal and Paramaribo.

• Signatures of Convection and Stratosphere Troposphere Exchange events can be detected in MOPITT CO data.

• Zonal mean height latitude cross sections of CO indicate convective transport in the southern tropics, possible signature of downward branch of Hadley cell (NH) and a seasonal migration of the boundary between the polluted northern hemisphere and relatively clean southern hemisphere.