Atmospheric Chemistry and Physics Discussions www.atmos-chem-phys-discuss.net 1680-7367 1680-7375 8 5 2008 10.5194/acpd-8-16981-2008 http://www.atmos-chem-phys-discuss.net/8/16981/2008/ http://www.atmos-chem-phys-discuss.net/8/16981/2008/acpd-8-16981-2008.html http://www.atmos-chem-phys-discuss.net/8/16981/2008/acpd-8-16981-2008.pdf 16981 17036 2008-09-10 Evaluating the performance of pyrogenic and biogenic emission inventories against one decade of space-based formaldehyde columns T. Stavrakou J.-F. Müller I. De Smedt M. Van Roozendael G. R. van der Werf L. Giglio A. Guenther Belgian Institute for Space Aeronomy, Avenue Circulaire 3, 1180, Brussels, Belgium Faculty of Earth and Life Sciences, Vrije Universiteit Amsterdam, De Boelelaan 1085, 1081 HV Amsterdam, The Netherlands Science Systems and Applications, Inc. NASA Goddard Space Flight Center, Greenbelt, MD 20771, USA National Center for Atmospheric Research, Boulder, CO 80303, USA A new one-decade dataset of formaldehyde (HCHO) columns retrieved from GOME and SCIAMACHY is compared with HCHO columns simulated by an updated version of the IMAGES global chemical transport model. This model version includes an optimized chemical scheme with respect to HCHO production, where the short-term and final HCHO yields from pyrogenically emitted non-methane volatile organic compounds (NMVOCs) are estimated from the Master Chemical Mechanism (MCM) and an explicit speciation profile of pyrogenic emissions. The model is driven by the Global Fire Emissions Database (GFED) version 1 or 2 for biomass burning, whereas biogenic emissions are provided either by the Global Emissions Inventory Activity (GEIA), or by a newly developed inventory based on the Model of Emissions of Gases and Aerosols from Nature (MEGAN) algorithms driven by meteorological fields from the European Centre for Medium-Range Weather Forecasts (ECMWF). The comparisons focus on tropical ecosystems, North America and China, which experience strong biogenic and biomass burning NMVOC emissions reflected in the enhanced measured HCHO columns. These comparisons aim at testing the ability of the model to reproduce the observed features of the HCHO distribution on the global scale and at providing a first assessment of the performance of the current emission inventories. The high correlation coefficients (<i>r</i>>0.8) between the observed and simulated columns over most regions indicate a very good consistency between the model, the implemented inventories and the HCHO dataset. The use of the MEGAN-ECMWF inventory improves the model/data agreement in almost all regions, but biases persist over parts of Africa and the Northern Australia. Although neither GFED version is consistent with the data over all regions, a better match is achieved over Indonesia and Southern Africa when GFEDv2 is used, but GFEDv1 succeeds better in getting the correct seasonal patterns and intensities of the fire episodes over the Amazon basin, as reflected by the higher correlations calculated in this region. Abbot, D., Palmer, P I., Martin, R V., Chance, K V., Jacob, D J., and Guenther, A.: Seasonal and interannual variability of North American isoprene emissions as determined by formaldehyde column measurements from space, Geophys. Res. Lett., 30, 17, doi:10.1029/2003GL017336, 2003. Andreae, M O. and Merlet, P.: Emission of trace gases and aerosols from biomass burning, Global Biogeochem. Cy., 15, 955–966, 2001. Aragão, L E O C., Malhi, Y., Roman-Cuesta, R M., Saatchi, S., Anderson, L O., and Shimabukuro, Y E.: Fingerprints of the 1997/1998 and 2005 droughts and their impact on the susceptibility of Amazonian rainforests to fires, Geophys. Phys. Lett., 34, L07701, doi:10.1029/2006GL028946, 2007. Atkinson, R.: Gas-phase tropospheric chemistry of organic compounds, J. Phys. Chem. Ref. Data, Monograph No. 2, 1994. Atkinson, R., Baulch, D. L., Cox, R. A., Crowley, J. N., Hampson, R. F., Hynes, R. G., Jenkin, M. E., Rossi, M. J., Troe, J., et al.: Evaluated kinetic and photochemical data for atmospheric chemistry: Volume II – gas phase reactions of organic species, Atmos. Chem. Phys., 6, 3625–4055, 2006. Boersma, K F., Eskes, H J., and Brinksma, E J.: Error analysis for tropospheric NO₂ retrieval from space, J. Geophys. Res., 109, D04311, doi:10.1029/2003JD003962, 2004. Brasseur, G P., Orlando, J J., and Tyndall, G S.: Atmospheric Chemistry and Global Change, Oxford University Press, 654 pp., 1999. Cantrell C A., Davidson, J A., McDaniel, A H., Shetter, R E., and Calvert, J G.: Temperature-dependent formaldehyde cross sections in the near-ultraviolet spectral region, J. Phys. Chem., 94, 3902–3908, 1990. Chance, K. and Spurr, R J D. : Ring effect studies: Rayleigh scattering including molecular parameters for rotational Raman scattering, and the Fraunhofer spectrum, Appl. Optics, 36, 5224–5230, 1997. Chance, K V., Palmer, P I., Spurr, R J D., Martin, R V., Kurosu, T P., and Jacob, D J.: Satellite observations of formaldehyde over North America from GOME, Geophys. Res. Lett., 27, 3461–3464, 2000. Cronin, L.: Key Guide to Australian Trees, Reed Natural History Australia, 191 pp., 2000. Damian, V., Sandu, A., Damian, M., Potra, F., and Carmichael, G R.: The Kinetic PreProcessor KPP – A Software Environment for Solving Chemical Kinetics, Comput. Chem. Eng., 26, 1567–1579, 2002. Dentener, F., Kinne, S., Bond, T., Boucher, O., Cofala, J., Generoso, S., Ginoux, P., Gong, S., Hoelzemann, J. J., Ito, A., Marelli, L., Penner, J. E., Putaud, J.-P., Textor, C., Schulz, M., van der Werf, G. R., and Wilson, J.: Emissions of primary aerosol and precursor gases in the years 2000 and 1750 prescribed data-sets for AeroCom, Atmos. Chem. Phys., 6, 4321–4344, 2006. De Smedt, I., Müller, J.-F., Stavrakou, T., van der A, R., Eskes, H., and Van Roozendael, M.: Twelve years of global observations of formaldehyde in the troposphere using GOME and SCIAMACHY sensors, Atmos. Chem. Phys., 8, 4947–4963, 2008. Evans, M J., Fiore, A., and Jacob, D J.: The GEOS-Chem chemical mechanism version 5-07-8, Harvard University, Cambridge, MA, USA, http://homepages.see.leeds.ac.uk/\~lecmje/GEOS-CHEM/geoschem_mech.pdf, 2003. Fried, A., Walega, J G., Olson, J R., Crawford, J H., Chen, G., Weibring, P., Richter, D., Roller, C., Tittel, F., Heikes, B G., Snow, J A., Shen, H., O'Sullivan, D W., Porter, M J., Fuelberg, H E., Halland, J J., and Millet, D B.: Formaldehyde over North America and the North Atlantic during the Summer 2004 INTEX Campaign: Methods, Observed Distributions, and Measurement-Comparisons, J. Geophys. Res., 113, D10302, doi:10.1029/2007JD009185, 2008. Fu, T.-M., Jacob, D J., Palmer, P I., Chance, K., Wang, Y X., Barletta, B., Blake, D R., Stanton, J C., and Pilling, M J.: Space-based formaldehyde measurements as constraints on volatile organic compound emissions in east and south Asia and implication for ozone, J. Geophys. Res., 112, D06312, doi:10.1029.2006JD007853, 2007. Geron, C., Owen, S., Guenther, A., Greenberg, J., Rasmussen, R., Bai, J H., Li, Q.-J., and Baker, B.: Volatile organic compounds from vegetation in southern Yunnan Province, China: Emission rates and some potential regional implications, Atmos. Environ., 40, 1759–1773, 2006. Giglio, L., Kendall, J D., and Mack, R.: A multi-year active fire dataset for the tropics derived from the TRMM VIRS, Int. J Remote Sens., 24, 22, 4505–4525, 2003. Giglio, L., van der Werf, G. R., Randerson, J. T., Collatz, G. J., and Kasibhatla, P.: Global estimation of burned area using MODIS active fire observations, Atmos. Chem. Phys., 6, 957–974, 2006. Giglio, L.: Characterization of the tropical diurnal fire cycle using VIRS and MODIS observations, Remote Sense Environ., 108, 407–421, 2007. Grainger, J. F. and Ring, J.: Anomalous Fraunhofer line profiles, Nature, 193, 762–762, 1962. Guenther, A., Hewitt, C N., Erickson, D., Fall, R., Geron, C., Graedel, T., Harley, P., Klinger, L., Lerdau, M., McKay, W A., Pierce, T., Scholes, B., Steinbrecher, R., Tallamraju, R., Taylor, J., and Zimmerman, P.: A global model of natural volatile organic compound emissions, J. Geophys. Res., 100, 8873–8892, 1995. Guenther, A., Karl, T., Harley, P., Wiedinmyer, C., Palmer, P I., and Geron, C.: Estimates of the global terrestrial isoprene emissions using MEGAN (Model of Emissions of Gases and Aerosols from Nature), Atmos. Chem. Phys., 6, 3181–3210, 2006. He, C., Murray, F., and Lyons, T.: Monoterpene and isoprene emissions from 15 \it Eucalyptus species in Australia, Atmos. Environ., 34, 645–655, 2000. Heikes, B., Snow, J., Egli, P., O'Sullivan, D., Crawford, J., Olson, J., Chen, G., Davis, D., Blake, N., and Blake, D.: Formaldehyde over the central Pacific during PEM-Tropics B, J. Geophys. Res., 106, D23, 32 717–32 731, 2001. Houweling, S., Dentener, F., and Lelieveld, J.: The impact of non-methane hydrocarbon compounds on tropospheric photochemistry, J. Geophys. Res., 103, 10 673–10 696, 1998. Jacob, D J., Field, B D., Li, Q., Blake, D R., de Gouw, J., Warneke, C., Hansel, A., Wisthaler, A., Singh, H B., and Guenther, A.: Global budget of methanol: constraints from atmospheric observations, J. Geophys. Res., 110, D08303, doi:10.1029/2004JD005172, 2005. Justice, C O., Giglio, L., Korontzi, S., Owens, J., Morisette, J T., Roy, D., Descloitres, J., Alleaume, S., Petitcolin, F., and Kaufman, Y.: The MODIS fire products, Remote Sens. Environ., 83, (1–2), 244–262, 2002. Karl, T., Guenther, A., Yokelson, R J., Greenberg, J., Potosnak, M., Blake, D R., and Artaxo, P.: The tropical forest and fire emissions experiment: Emission, chemistry, and transport of biogenic volatile organic compounds in the lower atmosphere over Amazonia, J. Geophys. Res., 112, D18302, doi:10.1029/2007JD008539, 2007. Khokhar, M F., Frankenberg, C., Van Roozendael, M., Beirle, S., Kühl, S., Richter, A., Platt, U., and Wagner, T.: Satellite observations of atmospheric SO₂ from volcanic eruptions during the time period of 1996 to 2002, Adv. Space Res., 36(5), 879–887, doi:10.1016/j.asr.2005.04.114, 2005. Koelemeijer, R B A., Stammes, P., Hovenier, J W., and de Haan, J F.: Global distributions of effective cloud fraction and cloud top pressure derived from oxygen A band spectra measured by the Global Ozone Monitoring Experiment: comparison to ISCCP data, J. Geophys. Res., 107, D12, 4151, doi:10.1029/2001JD000840, 2002. Koelemeijer, R B A., de Haan, J F., and Stammes, P.: A database of spectral surface reflectivity in the range 335–772 nm derived from 5.5~years of GOME observations, J. Geophys. Res., 108, D2, 4070, doi:10.1029/2002JD002429, 2003. Kuhn, U., Andreae, M O., Ammann, C., Araújo, A C., Brancaleoni, E., Ciccioli, P., Dindorf, T., Frattoni, M., Gatti, L V., Ganzeveld, L., Kruijt, B., Lelieveld, J., Lloyd, J., Meixner, F. X., Nobre, A D., Pöschl, U., Spirig, C., Stefani, P., Thielmann, A., Valentini, R., and Kesselmeier, J.: Isoprene and monoterpene fluxes from Central Amazonian rainforest inferred from tower-based and airborne measurements, and implications on the atmospheric chemistry and the local carbon budget, Atmos. Chem. Phys., 7, 2855–2879, 2007. Kylling, K., Stammes, P., and Tsay, S C.: A reliable and efficient two-stream algorithm for spherical radiative transfer: Documentation of accuracy in realistic layered media, J. Atmos. Phys., 21, 115–150, 1995. Lelieveld, J., Butler, T M., Crowley, J N., Dillon, T J., Fischer, H., Ganzeveld, L., Harder, H., Lawrence, M G., Martinez, M., Taraborelli, D., and Williams, J.: Atmospheric oxidation capacity sustained by a tropical forest, Nature, 452, 737–740, 2008. Li, Q., Jacob, D J., Yantosca, R M., Heald, C L., Singh, H B., Koike, M., Zhao, Y., Sachse, G W., and Streets, D G.: A global three-dimensional model analysis of the atmospheric budgets of HCN and CH₃CN: constraints from aircraft and ground measurements, J. Geophys. Res., 108, D21, 8827, doi:10.1029/2002JD003075, 2003. Madronich, S. and Flocke, S.: The role of solar radiation in atmospheric chemistry, in: Handbook of Environmental Chemistry, edited by: Boule, P., Springer Verlag, Heidelberg, 1–26, 1998. Marengo, J A., Nobre, C A., Tomasella, J., Oyama, M D., de Oliveira, G S., de Oliveira, R., Camargo, H., Alves, L M., and Brown, I F.: The drought of Amazonia in 2005, J. Climate, 21, 495–516, 2008. Martin, R V., Chance, K., Jacob, D J., Kurosu, T P., Spurr, R J D., Bucsela, E., Gleason, J F., Palmer, P I., Bey, I., Fiore, A M., Li, Q., Yantosca, R M., and Koelemeijer, R B A.: An improved retrieval of tropospheric nitrogen dioxide from GOME, J. Geophys. Res., 107, D20, doi:10.1029/2001JD001027, 2001. Martin, R V., Jacob, D J., Chance, K. V., Kurosu, T P., Palmer, P. I., and Evans, J.: Global inventory on nitrogen dioxide emissions constrained by space-based observations of NO₂ Columns, J. Geophys. Res., 108, D17, doi:10.1029/2003JD003453, 2003. Meller, R. and Moortgat, G K. : Temperature dependence of the absorption cross section of HCHO between 223 and 323 K in the wavelength range 225–375 nm, J. Geophys. Res., 105, D6, 7089–7102, doi:10.1029/1999JD901074, 2000. Meyer-Arnek, J., Ladstätter-Weiß enmayer, A., Richter, A., Wittrock, F., and Burrows, J P.: A study of trace gas columns of O₃, NO₂ and HCHO over Africa in September 1997, Faraday Discuss., 130, 387–405, 2005. Millet, D B., Jacob, D J., Turquety, S., Hudman, R C., Wu, S., Fried, A., Walega, J., Heikes, B G., Blake, D R., Singh, H B., Anderson, B E., and Clarke, A D.: Formaldehyde distribution over North America: implications for satellite retrievals of formaldehyde columns and isoprene emission, J. Geophys. Res., 111, D24S02, doi:10.1029/2005JD006853, 2006. Millet, D B., Jacob, D J., Fu, T.-M., Kurosu, T P., Chance, K., Heald, C L., and Guenther, A.: Spatial distribution of isoprene emissions from North America derived from formaldehyde column measurements by the OMI satellite sensor, J. Geophys. Res., 113, D02307, doi:10.1029/2007JD008950, 2008. Müller, J.-F. and Stavrakou, T.: Inversion of CO and NO_x emissions using the adjoint of the IMAGES model, Atmos. Chem. Phys., 5, 1157–1186, 2005. Müller, J.-F., Stavrakou, T., Wallens, S., De Smedt, I., Van Roozendael, M., Potosnak, M., Rinne, J., Munger, B., Goldstein, A., and Guenther, A. B.: Global isoprene emissions estimates using MEGAN, ECMWF analyses and a detailed canopy environment model, Atmos. Chem. Phys., 8, 1329–1341, 2008. Olivier, J~.G J., Berdowski, J J M., Peters, J A H W., Bakker, J., Visschedijk, A J H., and Bloos, J.-P J.: Applications of EDGAR. Including a description of EDGAR 3.0: reference database with trend data for 1970-1995, RIVM report no. 773301 001/ NOP report no. 410200 051, RIVM, Bilthoven, 2001. Olivier, J~.G J.: Part III: Greenhouse gas emissions. 1. Shares and trends in greenhouse gas emissions; 2. Sources and methods: greenhouse gas emissions for 1990 and 1995 in "CO₂ emissions from fuel combustion 1971–2000", 1–31, International Energy Agency, Paris, ISBN 92-64-09794-5, 2002. Olivier, J~.G J., Peters, J., Granier, C., Pétron, G., Müller, J.-F., and Wallens, S.: Present and future surface emissions of atmospheric compounds, POET Report 2, EU project EVK2-1999-00011, 2003. Otter, L., Guenther, A., Wiedinmyer, C., Fleming, G., Harley, P., and Greenberg, J.: Spatial and temporal variations in biogenic volatile organic compound emissions for Africa south of the equator, J. Geophys. Res., 108, D13, 8505, doi:10.1029/2002JD002609, 2003. Palmer, P I., Jacob, D J., Chance, K., Martin, R V., Spurr, R J D., Kurosu, T P., Bey, I., Yantosca, R., Fiore, A., and Li, Q.: Air-mass factor formulation for spectroscopic measurements from satellites: application to formaldehyde retrievals from GOME, J. Geophys. Res., 106, 14 539–14 550, 2001. Palmer, P., Abbot, D S., Fu, T.-M., Jacob, D J., Chance, K., Kurosu, T P., Guenther, A., Wiedinmyer, C., Stanton, J S., Pilling, M J., Pressley, S N., Lamb, B., and Summer, A L.: Quantifying the seasonal and interannual variability of North American isoprene emissions using satellite observations of the formaldehyde column, J. Geophys. Res., 111, D12315, doi:10.1029/2005JD006689, 2006. Palmer, P. I., Barkley, M. P., Kurosu, T. P., Lewis, A. C., Saxton, J. E., Chance, K., and Gatti, L. V.: Interpreting satellite column observations of formaldehyde over tropical South America, Phil. Trans. R. Soc. A., 365, 1741–1751, 2007. Peeters, J., Vereecken, L., and Fantechi, G.: The detailed mechanism of the OH-initiated atmospheric oxidation of alpha-pinene: a theoretical study, Phys. Chem. Chem. Phys., 3, 5489–5504, 2001. Pfister, G., Emmons, L K., Hess, P G., Lamarque, J.-F., Walters, S., Guenther, A., Palmer, P I., and Lawrence, P.: Contribution of isoprene to chemical budgets: A model tracer study with the NCAR CTM MOZART-4, J. Geophys. Res., 113, D05308, doi:10.1029/2007JD008948, 2008. Pinho, P G., Pio, C A., and Jenkin, M E.: Evaluation of isoprene degradation in the detailed tropospheric chemical mechanism, MCM v3, using environmental chamber data, Atmos. Environ., 39, 1303–1322, 2005. Platt, U.: Differential Optical Absorption Spectroscopy (DOAS), in: Air Monitoring by Spectroscopic Techniques, edited by: Sigrist, M W. John Wiley & Sons, Inc., New York, 1994. Pöschl, U., von Kuhlmann, R., Poisson, N., and Crutzen, P J.: Development and intercomparison of condensed isoprene oxidation mechanisms for global atmospheric modeling, J. Atmos. Chem., 37, 29–52, 2000. Richter, A. and Wagner, T.: Diffuser plate spectral structures and their influence on GOME slant columns, Tech. Note, Bremen Univ. and Heidelberg Univ., 2001. Rossow, W B., Walker, A W., Beuschel, D E., and Roiter, M D.: International Satellite Cloud Climatology Project (ISCCP) Documentation of New Cloud Datasets, Report WMO/TD-No. 737, World Meteorological Organization, Geneva, 115 pp., 1996. Sander, S P., Finlayson-Pitts, B J., Friedl, R R., Golden, D M., Huie, R E., Keller-Rudek, H., Kolb, C E., Kurylo, M J., Molina, M J., Moortgat, G K., Orkin, L V., Ravishankara, A R., and Wine, P H.: Chemical Kinetics and Photochemical data for use in atmospheric studies, Evaluation number 15, NASA Panel for data evaluation, JPL Publication 06-2, Jet Propulsion Laboratory, Pasadena, 2006. Sandu, A. and Sander, R.: Technical Note: Simulating chemical systems in Fortran90 and Matlab with the Kinetic PreProcessor KPP-2.1, Atmos. Chem. Phys., 6, 187–195, 2006. Saunders, S M., Jenkin, M E., Derwent, R G., and Pilling, M J.: Protocol for the development of the Master Chemical Mechanism, MCM v3 (Part A): tropospheric degradation of non-aromatic volatile organic compounds, Atmos. Chem. Phys., 3, 161–180, 2003. Singh H B., Brune, W H., Crawford, J H., Jacob, D J., and Russell, P B.: Overview of the summer 2004 Intercontinental Chemical Transport Experiment North America (INTEX-A), J. Geophys. Res., 111, D24S01, doi:10.1029/2006JD007905, 2006. Shim, C., Yang, Y., Choi, Y., Palmer, P I., Abbot, D., and Chance, K.: Constraining global isoprene emissions with Global Ozone Monitoring Experiment (GOME) formaldehyde column measurements, J. Geophys. Res., 110, D24301, doi:10.1029/2004JD005629, 2005. Smolarkiewicz, P K. and Rasch, P J.: Monotone advection on the sphere: An Eulerian versus semi-Lagrangian approach, J. Atmos. Sci., 48, 793–810, 1991. Stammes, K., Tsay, S C., Wiscombe, W., and Jayaweera, K.: Numerically stable algorithm for discrete-ordinate-method radiative transfer in multiple scattering and emitting layered media, Appl. Optics, 27, 2505–2509, 1988. Stavrakou, T. and Müller, J.-F.: Grid-base versus big region approach for inverting CO emissions using Measurement of Pollution in the Troposphere (MOPITT) data, J. Geophys. Res., 111, D15304, doi:10.1029/2005JD006896, 2006. Trostdorf, C R., Gatti, L V., Yamazaki, A., Potosnak, M J., Guenther, A., Martins, W C., and Munger, J W.: Seasonal cycles of isoprene concentrations in the Amazonian rainforest, Atmos. Chem. Phys. Discuss., 4, 1291–1310, 2004. Tyndall, G S., Orlando, J J., Wallington, T J., and Hurley, M D.: Products of the chlorine-atom- and hydroxyl-radical-initiated oxidation of CH₃CN, J. Phys. Chem. A, 105, 5380–5384, 2001. Uppala, S. M., Kallberg, P. W., Simmons, A. J., et al.: The ERA-40 re-analysis, Q. J. Roy. Meteor. Soc., 131, 2961–3012, doi:10.1256/qj.04.176., 2005. van der Werf, G R., Randerson, J T., Collatz, G J., and Giglio, L.: Carbon emissions from fires in tropical and subtropical ecosystems, Glob. Change Biol., 9, 547–562, 2003. van der Werf, G R., Randerson, J T., Collatz, G J., Giglio, L., Kasibhatla, P. S., Arellano, A F., Jr., Olsen, S C., and Kasischke, E S.: Continental scale partitioning of fire emissions during the 1997 to 2001 El Niño/La Niña period, Science, 303, 73–76, 2004. van der Werf, G R., Randerson, J T., Giglio, L., Collatz, G J., Kasibhatla, P S., and Arellano, Jr., A F.: Interannual variability in global biomass burning emissions from 1997 to 2004, Atmos. Chem. Phys., 6, 3423–3441, 2006. Van Roozendael, M., Fayt, C., Lambert, J.-C., Pundt, I., Wagner, T., Richter, A., and Chance, K.: Development of a bromine oxide product from GOME, in Proc. ESAMS'99, WPP-161, 543–547, 1999. Vereecken, L., Müller, J.-F., and Peeters, J.: Low-volatility poly-oxygenates in the OH-initiated atmospheric oxidation of α-pinene: impact of non-traditional peroxyl radical chemistry Phys. Chem. Chem. Phys., 9, 5241–5248, doi:10.1039/b708023a, 2007. Wallens, S.: Modélisation des émissions des composés organiques volatils par la végétation, Ph. D. Thesis, Université Libre de Bruxelles, 2004. Wang, P., Stammes, P., van der A, R., Pinardi, G., and van Roozendael, M.: FRESCO+: an improved O₂ A-band cloud retrieval algorithm for tropospheric trace gas retrievals, Atmos. Chem. Phys. Discuss., 8, 9697–9729, 2008. Wittrock, F., Richter, A., Ladstätter-Weiß enmayer, A., and Burrows, J P.: Global observations of formaldehyde, Proc. ERS-ENVISAT Symposium, ESA-Publ. SP-461, 2000. Wittrock F., Richter, A., Oetjen, H., Burrows, J. P., Kanakidou, M., Myriokefalitakis, S., Volkamer, R., Beirle, S., Platt, U., and Wagner, T. : Simultaneous global observations of glyoxal and formaldehyde from space, Geophys. Res. Lett., 33, L16804, doi:10.1029/2006GL026310, 2006. Zhang, P., Anderson, B., Barlow, M., Tan, B., and Myneni, R.: Climate related vegetation characteristics derived from MODIS LAI and NDVI, J. Geophys. Res., 109, D20105, doi:10.1029/2004JD004720, 2004.