What 10 Years of MOPITT Data What 10 Years of MOPITT Data Have Taught Us About Have Taught Us About

Tropospheric ChemistryTropospheric Chemistry

John GilleJohn Gille11, James Drummond, James Drummond22, David Edwards, David Edwards11, ,

Merritt DeeterMerritt Deeter11, Dallas Masters, Dallas Masters11, Louisa Emmons, Louisa Emmons11, ,

Gabi PfisterGabi Pfister11 and Valery Yudin and Valery Yudin11

1 1 National Center for Atmospheric ResearchNational Center for Atmospheric Research2 2 Dalhousie UniversityDalhousie University

MOPITT Measurements ofMOPITT Measurements of Atmospheric Carbon Monoxide Atmospheric Carbon Monoxide

MOPITT = Measurements Of Pollution In The Troposphere MOPITT = Measurements Of Pollution In The Troposphere Carbon monoxide (CO) results from incomplete combustion, Carbon monoxide (CO) results from incomplete combustion,

natural and anthropogenic, as well as the oxidation of CHnatural and anthropogenic, as well as the oxidation of CH44 and and some other organic compoundssome other organic compounds

It is present in the atmosphere from mixing ratios of ~ 60 ppbv (S. It is present in the atmosphere from mixing ratios of ~ 60 ppbv (S. Hemisphere) to ≥ 200 ppbv in polluted regions of the N. Hemisphere) to ≥ 200 ppbv in polluted regions of the N. Hemisphere. Rough global average ~ 125 ppbv at surfaceHemisphere. Rough global average ~ 125 ppbv at surface

Dominant sources are in the troposphere Dominant sources are in the troposphere (Mesospheric and thermospheric photolysis of CO(Mesospheric and thermospheric photolysis of CO22 not considered here) not considered here)

It is important as a sink of tropospheric OH, precursor to OIt is important as a sink of tropospheric OH, precursor to O33 formation, and tracer of its transport as well as that of other formation, and tracer of its transport as well as that of other pollutant gasespollutant gases

Prior to MOPITT Launch, only global data were 4 short periods of Prior to MOPITT Launch, only global data were 4 short periods of measurements by the MAPS instrument on the space shuttle measurements by the MAPS instrument on the space shuttle

CO Through the YearCO Through the Year

January 2009 April 2009

July 2009 October 2008

Total Columns in 1018 mol/cm2

Sensitivity of Tropical CO to ENSOSensitivity of Tropical CO to ENSO

• Low precipitation is associated with a higher fire count and high CO over the Maritime Continent. • While S. America and S. Africa are larger sources of CO, the Maritime continent is Responsible for the majority of the inter-annual variations.

• The large inter-annual varia-tions show the value of the longdata record.

MOPITT 700 hPa CO

EENSOENSO Precipitation Index

CO and FiresCO and Fires

MODIS FireCounts

MOPITT CO250 hPa

MOPITT CO 700 hPa

MODIS Fine Mode Aerosol Optical Depth

Biomass burning is a major source of CO in the tropics and Southern Hemisphere. Here MODIS and MOPITT data for 23-30 September 2003 illustrate the close spatial correspondence between fires, CO (especially low altitude) and fine aerosol products. CO from fires in S. America and Africa combine to fill the S. Atlantic, and cross the Indian Ocean.

(Edwards et al. JGR 2006a)

Boreal Fires

MOPITT data have helpedTo quantify the contributionsOf boreal fires to the global CO budgets.

Pfister et al. (JGR, 2005) used MOPITT data with the MOZART model to estimate the emissions from the 2001 Alaskan wildfires at 30±5 Tg CO, comparable to the anthropogenic emissions for the continental U.S. for the same time period.

Annual and Annual and Interannual VariabilityInterannual Variability

The source of the inter-annual variation is seen to be sources due to biomass burning in Indonesia and Australia.

CO at 700 hPa from 10°N to 65° S as a function of time. There is a clear annual cycle, as well as a large inter-annual variation centered on 20°S.

(Edwards et al., JGR 2006b)

Evidence for Long-Range TransportEvidence for Long-Range Transport

MOPITT COTotal Column1-9 Oct. 2003

Ground-basedFTIR & MOPITT Total Column Measurements

The top panel map shows high column amounts of CO coming from S. America and Africa in northern autumn, being advected across the Indian Ocean, Australia, New Zealand and beyond. The arrival of this plume over Lauder N.Z. is clearly shown in the FTIR data.

(Edwards et al.,JGR 2006a)

A recent development is the use A recent development is the use of adjoints of CTMof adjoints of CTM’’s to obtain s to obtain much more highly spatially much more highly spatially resolved determinations of resolved determinations of sources. The results shown sources. The results shown here are correction factors to here are correction factors to a priori Asian CO sources, a priori Asian CO sources, calculated by large regions, calculated by large regions, and by use of the adjoint, on and by use of the adjoint, on 2°x2.5° continental grid 2°x2.5° continental grid squares. squares.

Inversion to Obtain Source Locations and Strengths

(Kopacz et al, JGR 2009)

Wuhan

Beijing

ShanghaiChengdu

Hong Kong

A NEW CAPABILITY - CombingMOPITT TIR And NIR Channels

Surface CO based on TIR only Surface CO based on NIR + TIR

See H. Worden et al., Poster U33B-0059, (Wednesday Afternoon)

Recent work has made great progress in dealing with the channels measuring reflected solar radiation at 2.3 m. These give much more sensitivity to surface concentrations, and allow easier direct determination of surface sources, bypassing concerns about boundary layer venting to the free troposphere. This can also be used to help estimate CO2 source strengths.

What We Have Learned from MOPITTWhat We Have Learned from MOPITT

MOPITT retrievals show the large range of tropospheric CO mixing MOPITT retrievals show the large range of tropospheric CO mixing ratios, including spatial, annual and inter-annual variations. ratios, including spatial, annual and inter-annual variations.

With a lifetime of several weeks, CO (and gases from similar With a lifetime of several weeks, CO (and gases from similar sources with long lifetimes, e.g. Csources with long lifetimes, e.g. C22HH66) can be transported very long ) can be transported very long distances, and affect air quality far from its sources.distances, and affect air quality far from its sources.

MOPITT data can be assimilated in Chemical Transport Models and MOPITT data can be assimilated in Chemical Transport Models and inverted to yield inverted to yield ““top downtop down”” source locations and strengths, which source locations and strengths, which have frequently been shown to be more accurate than have frequently been shown to be more accurate than ““bottoms upbottoms up”” estimates.estimates.

CO is a precursor to the production of tropospheric ozone, important CO is a precursor to the production of tropospheric ozone, important in Earthin Earth’’s radiative balance, thus it also affects climate.s radiative balance, thus it also affects climate.

No one instrument can answer all questions. MOPITT data have No one instrument can answer all questions. MOPITT data have been used productively with data from other instruments, and with been used productively with data from other instruments, and with models, (but account must be taken of the Averaging Kernels). models, (but account must be taken of the Averaging Kernels).

GOING FORWARD, MOPITTGOING FORWARD, MOPITT’’s high sensitivity to surface CO from s high sensitivity to surface CO from simultaneous NIR and TIR signals promises to open new areas of simultaneous NIR and TIR signals promises to open new areas of research, including possibly estimating COresearch, including possibly estimating CO22 sources. sources.

Backup SlidesBackup Slides

Spring-timeSpring-timeTrans-Pacific TransportTrans-Pacific Transport

(Heald et al., JGR 2006)

MOPITT data have allowed more detailed studies of the transports of CO, particulates and other pollutants from S.E. Asia in northern spring. Many of these emissions are lifted from the surface into the mid-troposphere by advancing fronts. Not all reach North America.

Spring-time Trans-Pacific Transport is Episodic

(Gille and Lyjak, in preparation)

CO averaged from 20°-40°N at 500 hPa, showing the movement of alternating periods of high and low CO transported from E. Asia (~ 120°E) to the west coast of N. America (~ 240° E.) Transit time is ~5-7 days.

The origin is the periodic lifting by frontal passage in Asia, followed by transport with traveling highs and lows of meteorological waves.

Partitioning Variability between Sources and Transport

Pfister et al., ACPD 2009

Deviation from mean in total CO burden over Pacific and U.S. Range bars on abscissa include source and meteorological variability; Range bars or ordinate show meteorological variability with constant source, based on MOZART-4 and MOPITT data

Over Pacific, ½ of variability is due to meteorology, rest due to sources;over U.S. 2/3 of variability is due to meteorology.

Insight into the S. Atlantic Ozone Anomaly

MOPITT CO @ 700 hPa, 20-27 Jan. 2001 TOMS Tropospheric O3 column, January 1-27 2001

MOPITT CO x-section, 10°-14° E.

(Edwards et al., JGR 2003)

Flow schematic

Combined retrieval for MOPITT Thermal IR + Near IR (solar reflectance) channels Comparison with MOZAIC data for Delhi, 9/3/2004

TIR only NIR only TIR + NIR

Pres

sure

(hPa

)Pr

essu

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Pa)

Sedimentation of Aerosols Sedimentation of Aerosols from the Plumefrom the Plume

Although the aerosols and COhave common sources, the aerosols sediment out of the plumes, reducing the ratio of the enhanced AOD to the CO column with time.

These data are for biomass burning plumes exiting southern Africa over the Indian ocean between 15°- 40°S for the period 1-9 October 2003.

(Edwards et al., JGR 2006a)

Partitioning Variability between Sources and Transport

Pacific U.S.

Pfister et al., ACPD 2009

Correlation (r2) between absolute deviation from mean in total CO burden and different CO contributions over Pacific and U.S. Open bars include source variability, filled bars show constant source, based on MOPITT data and MOZART-4.Over Pacific, ½ of variability due to meteorology, rest due to sources;over U.S. 2/3 of variability due to meteorology.

It became apparent early on that It became apparent early on that modeling of MOPITT modeling of MOPITT measurements was not measurements was not possible without accurate possible without accurate information on the sources, information on the sources, which vary with time and which vary with time and location. location.

The type of differences are The type of differences are illustrated here. These illustrated here. These differences can be used with differences can be used with models and an inversion models and an inversion algorithm to estimate the algorithm to estimate the location and intensity of location and intensity of sources. sources.

MOPITT totalcolumn CO, 4-15 Nov. 2004 average

CO columnsfrom GEOS-Chem, emulating MOPITTobservations

Modeling MOPITT Observations

(Jones et al., ACP 2009)

Long Term Variability of Zonal MeansLong Term Variability of Zonal Means

Sensitivity of Tropical CO to ENSOSensitivity of Tropical CO to ENSO

a. ENSO precipitation indexa. ENSO precipitation index

b. MODIS normalized fire countb. MODIS normalized fire count

c. MOPITT 700 hPa CO mixing ratio c. MOPITT 700 hPa CO mixing ratio (ppbv) for individual SH regions.(ppbv) for individual SH regions.

Low precipitation is associated with a Low precipitation is associated with a higher fire count and high CO over higher fire count and high CO over the Maritime Continent. the Maritime Continent.

While S. America and S. Africa are While S. America and S. Africa are larger sources of CO, the Maritime larger sources of CO, the Maritime continent is responsible for the continent is responsible for the majority of the inter-annual majority of the inter-annual variations.variations.

What We Have Learned What We Have Learned from MOPITTfrom MOPITT

Biomass burning sources of CO are very variable from year to year, Biomass burning sources of CO are very variable from year to year, with sensitivity to climate;with sensitivity to climate;

As CO can lead to the production of tropospheric ozone, important As CO can lead to the production of tropospheric ozone, important in Earthin Earth’’s radiative balance, it also affects climate;s radiative balance, it also affects climate;

BottomBottom’’s up estimates of CO source strengths have frequently been s up estimates of CO source strengths have frequently been shown by comparison to MOPITT data to be underestimates; shown by comparison to MOPITT data to be underestimates;

MOPITT data can be assimilated in Chemical Transport Models and MOPITT data can be assimilated in Chemical Transport Models and inverted to yield source locations and strengths inverted to yield source locations and strengths

With a lifetime of several weeks, CO (and related gases with long With a lifetime of several weeks, CO (and related gases with long lifetimes, e.g. Clifetimes, e.g. C22HH66) can be transported very long distances, and ) can be transported very long distances, and affect air quality far from its sourcesaffect air quality far from its sources

No one instrument can answer all questions. MOPITT data have No one instrument can answer all questions. MOPITT data have been used productively with data from other instruments, and with been used productively with data from other instruments, and with models. models.

The use of reflected NIR and emitted TIR radiation will give The use of reflected NIR and emitted TIR radiation will give additional sensitivity to surface CO.additional sensitivity to surface CO.

Methodological Lessons Methodological Lessons from MOPITTfrom MOPITT

The use of Maximum a-Posteriori Likelihood is now much The use of Maximum a-Posteriori Likelihood is now much more widely employed and understood, including the use of more widely employed and understood, including the use of Averaging Kernels and Degrees of Freedom of the Signal, by Averaging Kernels and Degrees of Freedom of the Signal, by data users;data users;

Because of the low vertical resolution of the data, it is Because of the low vertical resolution of the data, it is usually desirable to use them in conjunction with models. usually desirable to use them in conjunction with models.

Assimilation, if done with proper care treatment of the Assimilation, if done with proper care treatment of the different vertical scales in the models and the data, will different vertical scales in the models and the data, will provide the most complete information from the data.provide the most complete information from the data.

Future DirectionsFuture Directions

TBSTBS

Combining NIR) with TIR Channels Increases Sensitivity to Surface CO

(Comparison with MOZAIC data for Delhi, 9/3/2004)

TIR only NIR only TIR + NIR

Pres

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(hPa

)Pr

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Pa)

AveragingKernels

Retrievals