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

Transcription

1 Interannual variability of CO and its relation to long-range transport and biomass burning A. Gloudemans1, J. de Laat1,2, H. Schrijver1, I. Aben1, J.F. Meirink2, G. vd Werf3, M. Krol1,4 SRON Netherlands Institute for Space Research 2 KNMI, 3VU, 4WUR 1

2 SCIAMACHY CO retrievals: a real challenge! CO lines SWIR ~ nm, sensitive down to Earth surface where the CO sources are CO lines are weak and often overlap with strong H2O and CH4 lines Important instrument calibration issues further complicate the CO retrievals, in particular: Presence of ice layer on the detector Increasing number of dead/bad detector pixels (radiation damage) Surface reflectance SWIR: Oceans <0.01 Densely vegetated areas ~0.05 Dry desert regions >0.5 Clouds ~

3 Enhanced carbon monoxide from Greek forest fires OMI aerosol index 3

4 New retrieval version: IMLM v7.4 Gloudemans et al. (2009) ACP, 9,

5 SCIAMACHY CO over the oceans: clouds Red: high clouds, small cloud top pressures Blue: low clouds, large cloud top pressures Gloudemans et al. (2009) Cloud top height (hpa) 5

6 SCIAMACHY CH4 cloud top pressures Low clouds: surface 800 hpa High clouds: pressure <800 hpa Gloudemans et al. (2009) 6

7 Interannual variability over Indonesia Gloudemans et al. (2009) ACP, 9,

8 Gloudemans et al. (2009) Atmospheric Science Conference September

9 Gloudemans et al. (2009) ACP, 9,

10 Transport of biomass-burning CO Gloudemans et al. (GRL, 2006) 10

11 South American emissions Van der Werf et al. (ACP, 2006) Gloudemans et al. (GRL, 2006) 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!! 11

12 Gloudemans et al. (2009) ACP, 9,

13 SCIAMACHY CO and transport of Asian pollution 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. 13

14 Conclusions SCIAMACHY can measure CO over the oceans above low clouds SCIAMACHY CO agrees well with model simulations Instrument noise error good indication of overall error in CO total columns, small bias (1.1017) compared to TM4-model Enhanced CO due to biomass burning, the corresponding long-range transport and their interannual variation are clearly seen: clear contribution of CO emitted by South-American forest fires to CO enhancements over Australia : >50% over central Australia in 2004 Long-range transport of pollution from Asia clearly seen Interannual variations can be studied: year-to-year changes in good agreement with MOPITT, models, FTIR,... 14

15 data available, more years under way contact : a.gloudemans@sron.nl Quick look of SCIAMACHY CO data with Google Earth: