AMFIC Progress Meeting, Barcelona, 24 June Space-nadir observations of formaldehyde, glyoxal and SO 2 columns with SCIAMACHY and GOME-2. Isabelle De Smedt, C. Lerot, J. Van Geffen, J. Stavrakou, J.-F. Muller, M. Van Roozendael. AMFIC Progress Meeting, Barcelona, 24 June Formaldehyde and Glyoxal Sources Anthr., 29% Fires, 20% Biog., 51% CH 4 oxidation 60% Biogenic 30% Anthropogenic 7% Fires 3% H 2 COCHOCHO Oxidation of CH 4 Oxidation of NMVOCs Direct emissions from fuel combustion biomass burning H 2 CO and CHOCHO are short-lived species with a lifetime of about a few hours. AMFIC Progress Meeting, Barcelona, 24 June Slant column retrieval: H 2 CO absorption cross-section of Meller and Moortgat (2000). Fitting interval: nm. Air mass factors determination: Look-up table of altitude-resolved scattering weights (DISORT). A-priori profile shapes from IMAGESv2 CTM. Cloud correction (Frescov5), no explicit correction for aerosols. De Smedt et al., ACP, 2008 H 2 CO total columns from GOME-2 Reference sector correction: Daily correction based on the IMAGES columns in the Pacific Ocean, where H 2 CO is only produced by methane oxidation. AMFIC Progress Meeting, Barcelona, 24 June H 2 CO Yearly Averaged Columns SCIAMACHY 2007GOME 1999 The better coverage of GOME-2 allows to reduce noise when averaging the observations. a better identification of the local emissions and of their spatial structure. GOME H 2 CO VCD x10 15 molec/cm GOME AMFIC Progress Meeting, Barcelona, 24 June Time series of monthly mean H 2 CO columns Very good agreement in tropical regions. In mid-latitudes, signal dominated by biogenic emissions. In winter, the GOME-2 columns underestimated. Central America South Eastern US GOME/ERS-2 SCIAMACHY/ENVISAT GOME-2/METOP-A AMFIC Progress Meeting, Barcelona, 24 June Max-DOAS H 2 CO columns in Beijing monthly averaged columns - 1OO km around Beijing The first version on the GOME-2 H 2 CO columns underestimated in Beijing. DOAS fit improvement: BrO fitted in a larger window ( nm). AMF (wavelength, SZA) applied to O 3 cross- sections. AMFIC Progress Meeting, Barcelona, 24 June H 2 CO columns in Beijing Comparison with Chimere results. AMFIC Progress Meeting, Barcelona, 24 June Averaging kernels H 2 CO columns in Beijing Comparison with Chimere results. H 2 CO Profile AMFIC Progress Meeting, Barcelona, 24 June H 2 CO columns in Beijing Comparison with Chimere results. AMFIC Progress Meeting, Barcelona, 24 June Glyoxal total columns from GOME-2 Fitting window: 435 nm 460 nm Correction for the liquid water absorption Air mass factors calculated with DISORT Daily normalization: 2e14 molec/cm in the Pacific reference sector C. Lerot, BIRA-IASB AMFIC Progress Meeting, Barcelona, 24 June Important seasonality observed by GOME-2. The GOME-2 averages strongly differ depending on the pixel selection. Nevertheless, a large statistics has to be ensured to have reliable values. Glyoxal from CHIMERE is strongly low-biased. Very preliminary!! CHOCHO columns in Beijing C. Lerot, BIRA-IASB AMFIC Progress Meeting, Barcelona, 24 June Glyoxal and formaldehyde from GOME-2 Anthropogenic emissions also contribute to high glyoxal and H 2 CO concentrations, especially in the Asias megacities. Such measurements offer the potential to improve the estimates of sources, and in particular to better discriminate the natural and anthropogenic sources. CHOCHOH 2 CO Population Density AMFIC Progress Meeting, Barcelona, 24 June SO 2 observations from satellite SO 2 is measured by different satellite-based instruments, both in the UV/Visible and the Infrared. SO 2 retrieval and monitoring at BIRA-IASB is primarily within the Support to Aviation Control Service (SACS) of GSE-PROMOTE, which will be extended beyond the end of PROMOTE (sept. 2009). Data in use comes from SCIAMACHY (retrieved at BIRA- IASB), GOME-2 (DLR) and OMI (NASA). Service is currently under reconstruction, to improve it and to prepare the service for future extensions (e.g. data from IASI). Will concentrate here on SCIAMACHY data since 2004. AMFIC Progress Meeting, Barcelona, 24 June SO 2 retrieval from SCIAMACHY Fitting window: nm. Interference with O 3 absorption corrected with a function SO 2 = A * (O 3 )^2, where A is a constant per month determined from a fit through the data of all months in SO 2 vertical column determined using air-mass factor look- up tables provided by DLR (for anthropogenic SO 2 the plume is assumed to be at 1 km above ground level). AMFIC Progress Meeting, Barcelona, 24 June SCIAMACHY SO 2 in Beijing J. Van Geffen, BIRA-IASB AMFIC Progress Meeting, Barcelona, 24 June SCIAMACHY and Max-DOAS SO 2 in Beijing SCIAMACHY SO 2 column over Beijing too low compared to the ground-based measurements during the winter months (SZA above 60 degrees). SCIAMACHY data still affected by a seasonal bias related to an ozone interference at large SZA. AMFIC Progress Meeting, Barcelona, 24 June SCIAMACHY SO 2 Time Series in Beijing SO 2 concentrations just north of Beijing much lower due to the location of mountains there: no local emissions. Assumptions: 1.Winter time measurements biased in the same way North and South of Beijing (same SZA). 2.Time-series should be flat North of Beijing. Correction of the artifact by subtracting SO 2 values North of Beijing outside the winter months from those South of Beijing (adding an offset of 0.2 DU). AMFIC Progress Meeting, Barcelona, 24 June Problem is only partly solved... SCIAMACHY and Max-DOAS SO2 in Beijing AMFIC Progress Meeting, Barcelona, 24 June SO 2 from GOME-2 over Beijing GOME-2 seems to be doing a little better than SCIA. GOME-2 data provided by Meike Rix and Pieter Valks, DLR. AMFIC Progress Meeting, Barcelona, 24 June GOME-2 H 2 CO: Retrieval improved at mid-latitudes: O 3 cross-section corrected with a 2D-AMF table. BrO fitted in a separated and larger window. GOME-2 columns are now ready to be distributed on the AMFIC website, together with SCIAMACHY columns. 2.GOME-2 CHOCHO: The impact of the liquid water retrieval on the glyoxal retrieval need to be evaluated more precisely. The retrieval errors (random and systematic) need to be estimated. 3.For Both H 2 CO and CHOCHO The aerosol effects need to be included in the AMF determination. More validation with ground-based products are needed. The synergistic use of H 2 CO and CHOCHO total columns may contribute to increase the constraints on pyrogenic and anthropogenic NMVOC emissions derived by inverse modelling techniques. Conclusions and perspectives AMFIC Progress Meeting, Barcelona, 24 June SO2: The SCIAMACHY columns are still under improvement, mainly in winter and at high SZA. GOME-2 columns seem to better match with ground-based measurements. GOME-2 columns currently provided by DLR but a scientific product will be developed at BIRA-IASB. Aerosols have to be taken into account in the AMF calculation. More validation data are needed in China! Conclusions and perspectives