Interannual variability of CO and its relation to long ...

A. Gloudemans1, J. de Laat1,2, H. Schrijver1, I. Aben1, J.F. Meirink2, G. vd Werf3, M. Krol1,4

Interannual variability of CO and its relation to long-range transport and biomass burning

11SRON Netherlands Institute for Space Research SRON Netherlands Institute for Space Research 22KNMI, KNMI, 33VU, VU, 44WURWUR

Atmospheric Science Conference - 7-11 September 2009 - Barcelona 2

SCIAMACHY CO retrievals: a real challenge!SCIAMACHY CO retrievals: a real challenge! CO lines SWIR ~2310-2380 nm, CO lines SWIR ~2310-2380 nm, sensitive down to Earth surface sensitive down to Earth surface where the CO sources arewhere the CO sources are CO lines are weak and often overlap with strong HCO lines are weak and often overlap with strong H22O and CHO and CH44 lines lines

Important instrument calibration issues further complicate the CO Important instrument calibration issues further complicate the CO retrievals, in particular:retrievals, in particular:Presence of ice layer on the detector Presence of ice layer on the detector Increasing number of dead/bad detector pixels (radiation damage)Increasing number of dead/bad detector pixels (radiation damage)

Surface reflectance SWIR: Surface reflectance SWIR: Oceans <0.01Oceans <0.01Densely vegetated areas ~0.05Densely vegetated areas ~0.05Dry desert regions >0.5Dry desert regions >0.5Clouds ~0.3-0.5Clouds ~0.3-0.5


Enhanced carbon monoxideEnhanced carbon monoxidefrom Greek forest firesfrom Greek forest fires

OMI aerosol index


New retrieval version: IMLM v7.4New retrieval version: IMLM v7.4

Gloudemans et al. (2009) ACP, 9, 3799-3813


SCIAMACHY CO over the oceans: cloudsSCIAMACHY CO over the oceans: clouds

• Use SWIR CH4 as cloud top height estimate

• Good agreement between CH4 cloud top height and FRESCO+ cloud top height

Red: high clouds, small cloud top pressures

Blue: low clouds, large cloud top pressures

Cloud top height (hPa)

Gloudemans et al. (2009)


SCIAMACHY CHSCIAMACHY CH44 cloud top pressures cloud top pressures

Low clouds: surface – 800 hPa

High clouds: pressure <800 hPa



Interannual variability over IndonesiaInterannual variability over Indonesia


Atmospheric Science Conference - 7-11 September 2009 - Barcelona 8http://www.nasa.gov/centers/goddard/news/topstory/2007/elnino_wildfire.html



Transport of biomass-burning COTransport of biomass-burning CO

Gloudemans et al. (GRL, 2006)


Gloudemans et al. (GRL, 2006)

Van der Werf et al. (ACP, 2006)

South American emissions

• S-America biomass-burning (BB) emissions much higher in 2004

• modeled emissions possibly still too low

• signal BB S-America primarily from S-America, peak Sept.

• signal BB Africa primarily from Africa, with a contribution from

S-America which lags in time ~few weeks.

• in Australia, depending on the location the main contribution

sometimes originates from BB in S-America !!


SCIAMACHY CO and transport of Asian pollutionSCIAMACHY CO and transport of Asian pollution

- Clouds are bright Clouds are bright sufficient signal to sufficient signal to noisenoise- Simultanously measured CH4 column: good Simultanously measured CH4 column: good proxy for cloud top height.proxy for cloud top height.- only use low cloudsonly use low clouds

- Annual 1x1 meanAnnual 1x1 mean- SCIA CO columns above cloud SCIA CO columns above cloud + TM4 below cloud = CO total + TM4 below cloud = CO total columncolumn

- SCIA CO columns above cloud onlySCIA CO columns above cloud only- TM4 above cloudTM4 above cloud- MOPITT total column – bias due to different MOPITT total column – bias due to different sensitivities (clouds, AVK, a priori,…)sensitivities (clouds, AVK, a priori,…)- Preliminary, qualitative comparison onlyPreliminary, qualitative comparison only- Detailed quantitative comparison of Detailed quantitative comparison of SCIAMACHY and MOPITT is in progressSCIAMACHY and MOPITT is in progress

Variability SCIAMACHY CO very similar to MOPITT

Turquety et al. (2008, ACP)

De Laat et al. (2009, submitted)See also poster by De Laat et al.


ConclusionsConclusions

• SCIAMACHY CO agrees well with model simulationsSCIAMACHY CO agrees well with model simulations

• Instrument noise error good indication of overall errorInstrument noise error good indication of overall error in CO total in CO total columns, small bias (1.10columns, small bias (1.101717) compared to TM4-model) compared to TM4-model

• Enhanced CO due to biomass burning and large scale pollution in Enhanced CO due to biomass burning and large scale pollution in Asia clearly seenAsia clearly seen

• SCIAMACHY CO data provides indication that SCIAMACHY CO data provides indication that GFEDv2 emissions GFEDv2 emissions may still be too lowmay still be too low

• SCIAMACHY CO sees long-range transport: SCIAMACHY CO sees long-range transport:

- clear contribution of CO emitted by South-American forest fires clear contribution of CO emitted by South-American forest fires to CO enhancements over Australiato CO enhancements over Australia : >50% over central : >50% over central Australia in 2004Australia in 2004

- Long range transport from AsiaLong range transport from Asia

• Interannual variations can be studied: 3 years available; Interannual variations can be studied: 3 years available;

more years are under waymore years are under way

• SCIAMACHY can measure CO over the oceans above low cloudsSCIAMACHY can measure CO over the oceans above low clouds

• SCIAMACHY CO agrees well with model simulationsSCIAMACHY CO agrees well with model simulations

• Instrument noise error good indication of overall errorInstrument noise error good indication of overall error in CO total in CO total columns, small bias (1.10columns, small bias (1.101717) compared to TM4-model) compared to TM4-model

• Enhanced CO due to biomass burning, the corresponding long-range Enhanced CO due to biomass burning, the corresponding long-range transport and their interannual variation are clearly seen:transport and their interannual variation are clearly seen:

clear contribution of CO emitted by South-American forest fires to CO clear contribution of CO emitted by South-American forest fires to CO enhancements over Australiaenhancements over Australia : >50% over central Australia in 2004 : >50% over central Australia in 2004

• Long-range transport of pollution from Asia clearly seenLong-range transport of pollution from Asia clearly seen

• Interannual variations can be studied: year-to-year changes in good Interannual variations can be studied: year-to-year changes in good agreement with MOPITT, models, FTIR, ....agreement with MOPITT, models, FTIR, ....

www.sciamachy.org/products

2003-2007 data available, more years under way

contact : [email protected]

Quick look of SCIAMACHY CO data with Google Earth:

http://www.sron.nl/google_earth

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Interannual variability of CO and its relation to long ...

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