1. M. Reuter, EGU, Vienna, Austria, 08.04.2011 Retrieval of atmospheric CO 2 from satellite near-infrared nadir spectra in the frame of ESA’s climate change initiative Retrieval of atmospheric CO 2 from satellite near-infrared nadir spectra in the frame of ESA’s climate change initiative M.Reuter, O.Schneising, M.Buchwitz, J.Heymann, H.Bovensmann, J.P.Burrows Institute of Environmental Physics, University of Bremen, Germany EGU, Vienna, Austria, 08.04.2011

2. M. Reuter, EGU, Vienna, Austria, 08.04.2011 Retrieval of atmospheric CO 2 from satellite near-infrared nadir spectra in the frame of ESA’s climate change initiative ESA’s GHG-CCI: Aims and Motivation

3. M. Reuter, EGU, Vienna, Austria, 08.04.2011 Retrieval of atmospheric CO 2 from satellite near-infrared nadir spectra in the frame of ESA’s climate change initiative ESA’s GHG-CCI: Road Map

4. M. Reuter, EGU, Vienna, Austria, 08.04.2011 Retrieval of atmospheric CO 2 from satellite near-infrared nadir spectra in the frame of ESA’s climate change initiative Two in-house algorithms BESD (XCO 2 )WFMD (XCO 2, XCH 4 ) Inversion Algorithm: Optimal Estimation; Full Physics Least-squares; Light path Proxy A-priori constraints: Yes Constant: CO2(p), aerosol, cirrus,... Per pixel: P, T, H2O,... No (constant atmosphere as linearization point for RT) Atmosphere: ECMWFUS Standard (sev. H2O) Aerosols: State vector (APS)Constant; AAI filter (CO2 only) Clouds: State vector (CWP, CTH); Filtering: MERIS 1x1 km 2 RT cloud free; Filtering: O2 & PMD (CO2 only) Fit windows: Merged fit windowsIndependent fit windows Radiative Transfer: SCIATRAN on-lineSCIATRAN LUT Speed: Slow (~15 min./pixel)Fast (~2 min./orbit) Optimized for: AccuracyCompromise accuracy/speed

5. M. Reuter, EGU, Vienna, Austria, 08.04.2011 Retrieval of atmospheric CO 2 from satellite near-infrared nadir spectra in the frame of ESA’s climate change initiative BESD XCO 2

6. M. Reuter, EGU, Vienna, Austria, 08.04.2011 Retrieval of atmospheric CO 2 from satellite near-infrared nadir spectra in the frame of ESA’s climate change initiative Validation with TCCON FTS measurements 350km Park Falls, USA 350km Bremen, Germany 350km Darwin, Australia 350km Lauder, New Zealand

7. M. Reuter, EGU, Vienna, Austria, 08.04.2011 Retrieval of atmospheric CO 2 from satellite near-infrared nadir spectra in the frame of ESA’s climate change initiative Comparison with FTS, CarbonTracker, GOSAT

8. M. Reuter, EGU, Vienna, Austria, 08.04.2011 Retrieval of atmospheric CO 2 from satellite near-infrared nadir spectra in the frame of ESA’s climate change initiative Statistics No statistical significant regional biases Single measurement precision ~2.5ppm Good agreement of year-to-year increase and seasonal amplitude

9. M. Reuter, EGU, Vienna, Austria, 08.04.2011 Retrieval of atmospheric CO 2 from satellite near-infrared nadir spectra in the frame of ESA’s climate change initiative WFMD XCO 2

10. M. Reuter, EGU, Vienna, Austria, 08.04.2011 Retrieval of atmospheric CO 2 from satellite near-infrared nadir spectra in the frame of ESA’s climate change initiative Global increase

11. M. Reuter, EGU, Vienna, Austria, 08.04.2011 Retrieval of atmospheric CO 2 from satellite near-infrared nadir spectra in the frame of ESA’s climate change initiative CO 2 uptake by growing vegetation Mean wind direction Longitude WestEast XCO 2 XCO 2 gradiant approximately proportional to net surface flux F net F net

12. M. Reuter, EGU, Vienna, Austria, 08.04.2011 Retrieval of atmospheric CO 2 from satellite near-infrared nadir spectra in the frame of ESA’s climate change initiative CO 2 uptake by growing vegetation Overall very good agreement Canada: Stronger CO 2 uptake ?Russia: Weaker CO 2 uptake ?

13. M. Reuter, EGU, Vienna, Austria, 08.04.2011 Retrieval of atmospheric CO 2 from satellite near-infrared nadir spectra in the frame of ESA’s climate change initiative http://www.esa-ghg-cci.org/ Intercomparison with other XCO 2 algorithms More Details: Poster: XY112 M. Buchwitz

14. M. Reuter, EGU, Vienna, Austria, 08.04.2011 Retrieval of atmospheric CO 2 from satellite near-infrared nadir spectra in the frame of ESA’s climate change initiative http://www.esa-ghg-cci.org/ THANKS!