Applications of space-borne Carbon- monoxide measurements in Atmospheric Chemistry and Air Quality Maarten Krol, Wageningen University / SRON / IMAU Jos de Laat (KNMI) & Annemieke Gloudemans & Ilse Aben (SRON) Jan Fokke Meirink (IMAU/KNMI) & Guido van der Werf (VU)
Research Question How can satellite measurements help to improve our knowledge on the CO budget?
Emission Catagory Tg/yearUncertainty Fossil + BioFuel % Tropical Fires 17070% Savanna Fires 26870% Extra-Tropical Fires 2970% Biogenic 16060% Oxidation (NMHC)73460% Oxidation (CH 4 )79620% Total2748 Stavrakou & Muller, 2006 Main Sink: oxidation by the OH radical
De Laat et al. GRL 2006 IMLM v6.3 September August 2004 De Laat et al. GRL 2006 SCIAMACHY CO NIR (like TROPOMI) Surface Sensitivity Large Noise Errors: Ice on detector Weak Lines Low NIR Albedo Averaging reduces noise related errors!
Gloudemans et al. GRL : Sampling model: at right place & time 2: Inaccurate measurements get smaller weight Biomass burning Tracer studies
Considerable contribution from longe-range transport e.g. from South America “Excess” CO column
de Laat et al., JGR, 2007 Improved Biomass Burning estimates
de Laat et al., JGR, 2007
Error estimate: x10 18 #/cm 2
SCIAMACHY CO over oceans IMLM 7.3 September December 2005 Over Land: CC < 20% Over Ocean: Cloud top > 800 hPa TM4 vs. SCIAMACHY
Modeled distribution consistent with SCIAMACHY observations TM4 on average too low (NH) Measurements over clouds!
Remarks on modelling: Models needed for quantitative analysis Data-assimilation: estimate “uncertain parameters” (emissions, initial composition) satellite applications: must ingest large amounts of data (SCIAMACHY, TES, MOPITT) All data sources have their own errors and biases: bias correction is required (e.g. ECMWF)
Available techniques Ensemble Kalman Filter (e.g. CarbonTracker) 4D-VAR (e.g. talk Ilse Aben, ECMWF) Application to CO underway...
TRANSCOM meeting: 2-6 June 2008, Utrecht Conclusions Development of models and assimilation techniques important for quantitative use satellite data SCIAMACHY CO: promising development Sensitivity down to Earth surface TROPOMI CO: higher resolution, more cloudfree pixels, 5x better sensitivity