ACPD Atmospheric Chemistry and Physics Discussions ACPD 1680-7375 Copernicus GmbH Göttingen, Germany 10.5194/acpd-9-9367-2009 Analysing spatio-temporal patterns of the global NO<sub>2</sub>-distribution retrieved from GOME satellite observations using a generalized additive model Hayn M. 1 Beirle S. 2 Hamprecht F. A. 3 Platt U. 4 Menze B. H. 3 5 Wagner T. 2 Institut für Mathematik, University of Potsdam, Potsdam, Germany MPI for Chemistry, Mainz, Germany Interdisciplinary Center for Scientific Computing, University of Heidelberg, Heidelberg, Germany Institut für Umweltphysik, University of Heidelberg, Heidelberg, Germany Computer Science and Artificial Intelligence Lab, Massachusetts Institute of Technology, Cambridge/MA, USA 09 04 2009 9 2 9367 9398 This is an open-access article ditributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. This article is available from http://www.atmos-chem-phys-discuss.net/9/9367/2009/acpd-9-9367-2009.html The full text article is available as a PDF file from http://www.atmos-chem-phys-discuss.net/9/9367/2009/acpd-9-9367-2009.pdf

With the increasing availability of observations from different space-borne sensors, the joint analysis of observational data from multiple sources becomes more and more attractive. For such an analysis – oftentimes with little prior knowledge about local and global interactions between the different observational variables available – an explorative data-driven analysis of the remote sensing data may be of particular relevance. <br><br> In the present work we used generalized additive models (GAM) in this task, in an exemplary study of spatio-temporal patterns in the tropospheric NO<sub>2</sub>-distribution derived from GOME satellite observations (1996 to 2001) at global scale. We modelled different temporal trends in the time series of the observed NO<sub>2</sub>, but focused on identifying correlations between NO<sub>2</sub> and local wind fields. Here, our nonparametric modelling approach had several advantages over standard parametric models: While the model-based analysis allowed to test predefined hypotheses (assuming, for example, sinusoidal seasonal trends) only, the GAM allowed to learn functional relations between different observational variables directly from the data. This was of particular interest in the present task, as little was known about relations between the observed NO<sub>2</sub> distribution and transport processes by local wind fields, and the formulation of general functional relationships to be tested remained difficult. <br><br> We found the observed temporal trends – weekly, seasonal and linear changes – to be in overall good agreement with previous studies and alternative ways of data analysis. However, NO<sub>2</sub> observations showed to be affected by wind-dominated processes over several areas, world wide. Here we were able to estimate the extent of areas affected by specific NO<sub>2</sub> emission sources, and to highlight likely atmospheric transport pathways. Overall, using a nonparametric model provided favourable means for a rapid inspection of this large spatio-temporal data set,with less bias than parametric approaches, and allowing to visualize dynamical processes of the NO<sub>2</sub> distribution at a global scale.

 References Aldrin, M. and Haff, I. H.: Generalised additive modelling of air pollution, traffic volume and meteorology, Atmos. Environ., 39(11), 2145–2155, 2005. Beirle, S., Platt, U., Wenig, M., and Wagner, T.: Weekly cycle of NO<sub>2</sub> by GOME measurements: a signature of anthropogenic sources, Atmos. Chem. Phys., 3, 2225–2232, 2003. Beirle, S.: Estimating source strengths and lifetime of Nitrogen Oxides from satellite data, PhD thesis, Ruperto-Carola University of Heidelberg, Germany, 2004. Beirle, S., Platt, U., Wenig, M., and Wagner, T.: NO<sub>x</sub> production by lightning estimated with GOME, Adv. Space Res., 793–797, 2004. 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. Bovensmann, H., Burrows, J. P., Buchwitz, M. et al.: SCIAMACHY: Mission Objectives and Measurement Modes, J. Atmos. Sci., 56(2), 127–150, 1999. Brillinger, D.: An application of statistics to meteorology: estimation of motion, in:Festschrift for Lucien Le Cam, edited by: Pollard, D. and Yang, G., Springer, New York, 1994. % %Burrows, J. P., Rozanov, V. V., Vountas, M., Richter, A., Platt, U., Haug, %H., Marquard, L., and Chance, K.: Study of the Ring effect, Final Report for ESA Contract %10996/94/NL/CN, 1994. Burrows, J. P., Weber, M., Buchwitz, M., et al.: The Global Ozone Monitoring Experiment (GOME): Mission concept and first results, J. Atmos. Sci., 56, 151–175, 1999. Craven, P. and Wahba, G.: Smoothing noisy data with spline functions, Numer. Math., 31, 377–403, 1979. Dominici, F., McDermott, A., S. L. Zeger, et al.: On the Use of Generalized Additive Models in Time-Series Studies of Air Pollution and Health, Am. J. Epidemiol., 156(3), 193–203, 2002. Elsayed, N. M.: Toxicity of nitrogen dioxide: an introduction, Toxicology, 89(3), 161–74, 1994. ESA: Global Ozone Monitoring Experiment (GOME), Users Manual, ESA Publications Devision, SP-1182, edited by: Bednarz, F., ISBN: 92-9092-327, 1995. Grzegorski, M., Wenig, M., Platt, U., Stammes, P., Fournier, N., and Wagner, T.: The Heidelberg iterative cloud retrieval utilities (HICRU) and its application to GOME data, Atmos. Chem. Phys., 6, 4461–4476, 2006. Hastie, T. J. and Tibshirani, R. J.: Generalized Additive Models, Statistical Science, 1(3), 297–318, 1986. Hastie, T. J. and Tibshirani, R. J.: Generalized Additive Models, Chapman & Hall/CRC, 1990. Jacob, D. J.: Introduction to Atmospheric Chemistry, Princeton University Press, 1999. Jaeglé, L., Martin, R. V., Chance, K., et al.: Satellite mapping of rain-induced nitric oxide emissions from soils, J. Geophys. Res., 109, D21310, doi:10.1029/2004JD004787, 2004. K&aring;llberg, P., Simmons, A., Uppala, S., and Fuentes, M.: ECMWF: The ERA-40 Archive, ERA-40 Project Report Series No. 17, 2004. Kim, J. and Hong, J.: A GAM for Daily Ozone Concentration in Seoul, Key Eng. Mat., 277–279, 497–502, 2005. Leue, C., Wenig, M., Wagner, T., Klimm, O., Platt, U., and Jähne, B.: Quantitative analysis of NO<sub>x</sub> emissions from GOME satellite image sequences, J. Geophys. Res., 106(D6), 5493–5505, 2001. Martin, R. V., Chance, K., Jacob, D. J., et al.: An improved retrieval of tropospheric nitrogen dioxide from GOME, J. Geophys. Res., 107(D20), 4437, doi:10.1029/2001JD001027, 2002. McCullagh, P. and Nelder, J. A.: Generalized Linear Models, London: Chapman and Hall, 1989. Olivier et al.: Global air emission inventories for anthropogenic sources of NOx, NH3 and N<sub>2</sub>O in 1990, Environ. Pollut., 102, 135–148, 1990. Platt, U.: Differential optical absorption spectroscopy (DOAS), In: Sigrist, M., editor, Air Monitoring by Spectrometric Techniques, 27–84, John Wiley, New York, 1994. Richter, A. and Burrows, J. P.: Tropospheric NO2 from GOME Measurements, Adv. Space Res., 29(11), 1673–1683, 2002. Richter, A., Burrows, J. P., Nüß, H., Granier, C., and Niemeier, U.: Increase in tropospheric nitrogen dioxide over China observed from space, Nature, 437(7055), 129–132, 2005. Seinfeld, J. H. and Pandis, S. N.: Atmospheric Chemistry and Physics, John Wiley and Sons, 1997. Smith, R. L., Davis, J. M., and Speckman, P.: Human health effects of environmental pollution in the atmosphere, In: Barnett V, Stein A, Turkman F, eds. Statistics in the environment 4: statistical aspects of health and the environment, 91–115, Chichester, United Kingdom: John Wiley & Sons Ltd, citeseer.ist.psu.edu/rl99human.html, 1999. Solomon, S., Schmeltekopf, A. L., and Sanders, R. W.: On the interpretation of zenith sky absorption measurements, J. Geophys. Res., 92, 8311–8319, 1987. Stige, L. C., Stave, J., Chan, K.-S., Ciannelli, L., Pettorelli, N., Glantz, M., Herren, H. R., and Stenseth, N. C.: The effect of climate variation on agro-pastoral production in Africa, Proceedings of the National Academy of Sciences, PNAS, 103(9), 2006. Stohl, A., Huntrieser, H., Richter, A., Beirle, S., Cooper, O. R., Eckhardt, S., Forster, C., James, P., Spichtinger, N., Wenig, M., Wagner, T., Burrows, J. P., and Platt, U.: Rapid intercontinental air pollution transport associated with a meteorological bomb, Atmos. Chem. Phys., 3, 969–985, 2003. Toutenburg, H. and Heumann, C.: Induktive Statistik, Eine Einführung mit R und SPSS Reihe, Springer-Lehrbuch, 2008. Uno, I., Ohara, T., and Wakamatsu, S.: Analysis of wintertime NO<sub>2</sub> pollution in the Tokyo Metropolitan area, Atmos. Environ., 30(5), 703–713(11), 1996. van der A, R. J., Peters, D. H. M. U.,, Eskes, Boersma, K. F., Van Roozendael, M., De Smedt, I., and Kelder, H. M.: Detection of the trend and seasonal variation in tropospheric NO<sub>2</sub> over China, J. Geophys. Res., 111, D12317, doi:10.1029/2005JD006594 2006. van der A, R. J., Eskes, H. J., Boersma, K. F., van Noije, T. P. C., Van Roozendael, M., De Smedt, I., Peters, D. H. M. U., Kuenen, J. J. P., and Meijer, E. W.: Identification of NO<sub>2</sub> sources and their trends from space using seasonal variability analyses, J. Geophys. Res., 113, doi:10.1029/2007JD009021, 2008. Velders, G. J. M., Granier, C., Portmann, R. W., Pfeilsticker, K., Wenig, M., Wagner, T., Platt, U., Richter, A., and Burrows, J. P.: Global tropospheric NO<sub>2</sub> column distributions: Comparing three-dimensional model calculations with GOME measurements, J. Geophys. Res., 106(D12), 12643–12660, 2001. Wagner, T., Beirle, S., Deutschmann, T., Eigemeier, E., Frankenberg, C., Grzegorski, M., Liu, C., Marbach, T., Platt, U., and Penning de Vries, M.: Monitoring of atmospheric trace gases, clouds, aerosols and surface properties from UV/vis/NIR satellite instruments, J. Opt. A: Pure Appl. Opt., 10, 104019, doi:10.1088/1464-4258/10/10/104019, 2008. Wakamatsu, S., Uno, I., and Ohara, T.: Springtime Photochemical Air Pollution in Osaka: Field Observation, J. Appl. Meteorol., 37, 1100–1106, 1998. Wenig, M., Spichtinger, N., Stohl, A., Held, G., Beirle, S., Wagner, T., Jähne, B., and Platt, U.: Intercontinental transport of nitrogen oxide pollution plumes, Atmos. Chem. Phys., 3, 387–393, 2003. Wood, S. N.: Generalized Additive Models: An Introduction with R, Chapman & Hall/CRC, Taylor & Francis Group, 2006. World Health Organization, Health Aspects of Air. Pollution with Particulate Matter, Ozone and Nitrogen Dioxide. Report on a WHO Working Group, 13–15 January 2003, Bonn, Germany.