ACP Atmospheric Chemistry and Physics ACP 1680-7324 Copernicus GmbH Göttingen, Germany 10.5194/acp-12-8851-2012 Analysis of stratospheric NO<sub>2</sub> trends above Jungfraujoch using ground-based UV-visible, FTIR, and satellite nadir observations Hendrick F. 1 Mahieu E. 2 Bodeker G. E. 3 Boersma K. F. 4 5 Chipperfield M. P. 6 De Mazière M. 1 De Smedt I. 1 Demoulin P. 2 Fayt C. 1 Hermans C. 1 Kreher K. 7 Lejeune B. 2 Pinardi G. 1 Servais C. 2 Stübi R. 8 van der A R. 4 Vernier J.-P. 9 10 Van Roozendael M. 1 Belgian Institute for Space Aeronomy (BIRA-IASB), Brussels, Belgium Institute of Astrophysics and Geophysics of the University of Liège, Liège, Belgium Bodeker Scientific, Alexandra, New Zealand Royal Netherlands Meteorological Institute (KNMI), De Bilt, The Netherlands Eindhoven University of Technology, Eindhoven, The Netherlands School of Earth and Environment, University of Leeds, Leeds, UK National Institute of Water and Atmospheric Research, Omakau, Central Otago, New Zealand MeteoSwiss, Payerne, Switzerland Science Systems and Applications, Inc., Hampton, Virginia, USA NASA Langley Research Center, Hampton, Virginia, USA 28 09 2012 12 18 8851 8864 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.net/12/8851/2012/acp-12-8851-2012.html The full text article is available as a PDF file from http://www.atmos-chem-phys.net/12/8851/2012/acp-12-8851-2012.pdf

The trend in stratospheric NO<sub>2</sub> column at the NDACC (Network for the Detection of Atmospheric Composition Change) station of Jungfraujoch (46.5° N, 8.0° E) is assessed using ground-based FTIR and zenith-scattered visible sunlight SAOZ measurements over the period 1990 to 2009 as well as a composite satellite nadir data set constructed from ERS-2/GOME, ENVISAT/SCIAMACHY, and METOP-A/GOME-2 observations over the 1996–2009 period. To calculate the trends, a linear least squares regression model including explanatory variables for a linear trend, the mean annual cycle, the quasi-biennial oscillation (QBO), solar activity, and stratospheric aerosol loading is used. For the 1990–2009 period, statistically indistinguishable trends of −3.7 ± 1.1% decade<sup>−1</sup> and −3.6 ± 0.9% decade<sup>−1</sup> are derived for the SAOZ and FTIR NO<sub>2</sub> column time series, respectively. SAOZ, FTIR, and satellite nadir data sets show a similar decrease over the 1996–2009 period, with trends of −2.4 ± 1.1% decade<sup>−1</sup>, −4.3 ± 1.4% decade<sup>−1</sup>, and −3.6 ± 2.2% decade<sup>−1</sup>, respectively. The fact that these declines are opposite in sign to the globally observed +2.5% decade<sup>−1</sup> trend in N<sub>2</sub>O, suggests that factors other than N<sub>2</sub>O are driving the evolution of stratospheric NO<sub>2</sub> at northern mid-latitudes. Possible causes of the decrease in stratospheric NO<sub>2</sub> columns have been investigated. The most likely cause is a change in the NO<sub>2</sub>/NO partitioning in favor of NO, due to a possible stratospheric cooling and a decrease in stratospheric chlorine content, the latter being further confirmed by the negative trend in the ClONO<sub>2</sub> column derived from FTIR observations at Jungfraujoch. Decreasing ClO concentrations slows the NO + ClO → NO<sub>2</sub> + Cl reaction and a stratospheric cooling slows the NO + O<sub>3</sub> → NO<sub>2</sub> + O<sub>2</sub> reaction, leaving more NO<sub>x</sub> in the form of NO. The slightly positive trends in ozone estimated from ground- and satellite-based data sets are also consistent with the decrease of NO<sub>2</sub> through the NO<sub>2</sub> + O<sub>3</sub> → NO<sub>3</sub> + O<sub>2</sub> reaction. Finally, we cannot rule out the possibility that a strengthening of the Dobson-Brewer circulation, which reduces the time available for N<sub>2</sub>O photolysis in the stratosphere, could also contribute to the observed decline in stratospheric NO<sub>2</sub> above Jungfraujoch.

 References Angelbratt,~J., Mellqvist,~J., Blumenstock,~T., Borsdorff,~T., Brohede,~S., Duchatelet,~P., Forster,~F., Hase,~F., Mahieu,~E., Murtagh,~D., Petersen,~A K., Schneider,~M., Sussmann,~R., and Urban,~J.: A new method to detect long term trends of methane (\chemCH_4) and nitrous oxide (\chemN_2O) total columns measured within the NDACC ground-based high resolution solar FTIR network, Atmos. Chem. Phys., 11, 6167–6183, http://dx.doi.org/10.5194/acp-11-6167-2011doi:10.5194/acp-11-6167-2011, 2011. Bodeker,~G E., Boyd,~I S., and Matthews,~W A.: Trends and variability in vertical ozone and temperature profiles measured by ozonesondes at Lauder, New Zealand: 1986–1996, J Geophys. Res., 103, 28661–28681, 1998. Bodeker,~G E., Shiona,~H., and Eskes,~H.: Indicators of Antarctic ozone depletion, Atmos. Chem. Phys., 5, 2603–2615, http://dx.doi.org/10.5194/acp-5-2603-2005doi:10.5194/acp-5-2603-2005, 2005. Boersma,~K F., Eskes,~H J., and Brinksma,~E J.: Error analysis for tropospheric \chemNO_2 retrieval from space, J Geophys. Res., 109, D04311, http://dx.doi.org/10.1029/2003JD003962doi:10.1029/2003JD003962, 2004. Boersma,~K F., Eskes,~H J., Veefkind,~J P., Brinksma,~E J., van~der~ A,~R J., Sneep,~M., van~den~Oord,~G H J., Levelt,~P F., Stammes,~P., Gleason,~J F., and Bucsela,~E J.: Near-real time retrieval of tropospheric \chemNO_2 from OMI, Atmos. Chem. Phys., 7, 2103–2118, http://dx.doi.org/10.5194/acp-7-2103-2007doi:10.5194/acp-7-2103-2007, 2007. Brohede,~S., McLinden,~C A., Urban,~J., Haley,~C S., Jonsson,~A I., and Murtagh,~D.: Odin stratospheric proxy \chemNO_y measurements and climatology, Atmos. Chem. Phys., 8, 5731–5754, http://dx.doi.org/10.5194/acp-8-5731-2008doi:10.5194/acp-8-5731-2008, 2008. Chang,~L., Palo,~S., Hagan,~M., Richter,~J., Garcia,~R., Riggin,~D., and Frittz,~D.: Structure of the migrating diurnal tide in the whole atmosphere community climate model, Adv. Space Res., 41, 1398–1407, 2008. Chipperfield,~M P.: New version of the TOMCAT/SLIMCAT off-line chemical transport model: intercomparison of stratospheric tracer experiments, Q J. Roy. Meteor. Soc., 132, 1179–1203, http://dx.doi.org/10.1256/qj.05.51doi:10.1256/qj.05.51, 2006. Cook,~P A. and Roscoe,~H K.: Variability and trends in stratospheric \chemNO_2 in Antarctic summer, and implications for stratospheric \chemNO_y, Atmos. Chem. Phys., 9, 3601–3612, http://dx.doi.org/10.5194/acp-9-3601-2009doi:10.5194/acp-9-3601-2009, 2009. Crutzen,~P J.: The role of NO and \chemNO_2 in the chemistry of the troposphere and stratosphere, Annual Review of Earth and Planetary Sciences, vol 7 (A79-37176 15-42), Annual Reviews, Inc., Palo Alto, California, USA, 443–472, 1979. Dirksen,~R J., Boersma,~K F., Eskes,~H J., Ionov,~D V., Bucsela,~E J., Levelt,~P F., and Kelder,~H M.: Evaluation of stratospheric \chemNO_2 retrieved from the ozone monitoring instrument: intercomparison, diurnal cycle, and trending, J Geophys. Res., 116, D08305, http://dx.doi.org/10.129/2010JD014943doi:10.129/2010JD014943, 2011. Fish,~D J., Roscoe,~H K., and Johnston,~P V.: Possible causes of stratospheric \chemNO_2 trend observed at Lauder, New Zealand, Geophys. Res. Lett., 27, 3313–3316, 2000. Gil,~M., Yela,~M., Gunn,~L. N., Richter,~A., Alonso,~I., Chipperfield,~M. P., Cuevas,~E., Iglesias,~J., Navarro,~M., Puentedura,~O., and Rodriguez,~S.: \chemNO_2 climatology in the northern subtropical region: diurnal, seasonal and interannual variability, Atmos. Chem. Phys., 8, 1635–1648, http://dx.doi.org/10.5194/acp-8-1635-2008doi:10.5194/acp-8-1635-2008, 2008. Grainger,~J. and Ring,~J.: Anomalous Fraunhofer line profiles, Nature, 193, p 762, 1962. Gruzdev,~A N.: Latitudinal structure of variations and trends in stratospheric \chemNO_2, Int J. Remote Sens., 30, 4227–4246, 2009. Hendrick,~F., Barret,~B., Van~Roozendael,~M., Boesch,~H., Butz,~A., De~Mazière,~M., Goutail,~F., Hermans,~C., Lambert,~J.-C., Pfeilsticker,~K., and Pommereau,~J.-P.: Retrieval of nitrogen dioxide stratospheric profiles from ground-based zenith-sky UV-visible observations: validation of the technique through correlative comparisons, Atmos. Chem. Phys., 4, 2091–2106, http://dx.doi.org/10.5194/acp-4-2091-2004doi:10.5194/acp-4-2091-2004, 2004. Hendrick,~F., Van Roozendael,~M., Kylling,~A., Petritoli,~A., Rozanov,~A., Sanghavi,~S., Schofield,~R., von Friedeburg,~C., Wagner,~T., Wittrock,~F., Fonteyn,~D., and De Mazière,~M.: Intercomparison exercise between different radiative transfer models used for the interpretation of ground-based zenith-sky and multi-axis DOAS observations, Atmos. Chem. Phys., 6, 93–108, http://dx.doi.org/10.5194/acp-6-93-2006doi:10.5194/acp-6-93-2006, 2006. Hendrick,~F., Johnston,~P V., Kreher,~K., Hermans,~C., De Mazière,~M., and Van Roozendael,~M.: One decade trend analysis of stratospheric BrO over Harestua (60\degree N) and Lauder (45\degree S) reveals a decline, Geophys. Res. Lett., 35, L14801, http://dx.doi.org/10.1029/2008GL034154doi:10.1029/2008GL034154, 2008. Kohlhepp,~R., Ruhnke,~R., Chipperfield,~M P., De~Mazière,~M., Notholt,~J., Barthlott,~S., Batchelor,~R L., Blatherwick,~R D., Blumenstock,~Th., Coffey,~M T., Demoulin,~P., Fast,~H., Feng,~W., Goldman,~A., Griffith,~D W T., Hamann,~K., Hannigan,~J W., Hase,~F., Jones,~N B., Kagawa,~A., Kaiser,~I., Kasai,~Y., Kirner,~O., Kouker,~W., Lindenmaier,~R., Mahieu,~E., Mittermeier,~R L., Monge-Sanz,~B., Morino,~I., Murata,~I., Nakajima,~H., Palm,~M., Paton-Walsh,~C., Raffalski,~U., Reddmann,~Th., Rettinger,~M., Rinsland,~C P., Rozanov,~E., Schneider,~M., Senten,~C., Servais,~C., Sinnhuber,~B.-M., Smale,~D., Strong,~K., Sussmann,~R., Taylor,~J R., Vanhaelewyn,~G., Warneke,~T., Whaley,~C., Wiehle,~M., and Wood,~S W.: Observed and simulated time evolution of HCl, ClO\chemNO_2, and HF total column abundances, Atmos. Chem. Phys., 12, 3527–3556, http://dx.doi.org/10.5194/acp-12-3527-2012doi:10.5194/acp-12-3527-2012, 2012. Liley,~J B., Johnston,~P V., McKenzie,~R L., Thomas,~A J., and Boyd,~I S.: Stratospheric \chemNO_2 variations from a long time series at Lauder, New Zealand, J Geophys. Res., 105, 11633–11640, 2000. McLinden,~C A., Olsen,~S C., and Prather,~M J.: Understanding trends in stratospheric \chemNO_y and \chemNO_2, J Geophys. Res., 106, 27787–27793, 2001. Platt,~U. and Stuz,~J.: Differential Optical Absorption Spectroscopy (DOAS), Principles and Applications, ISBN 978-3-540-21193-8, Springer, Berlin, Heidelberg, Germany, 2008. Pommereau,~J.-P. and Goutail,~F.: \chemO_3 and \chemNO_2 ground-based measurements by visible spectrometry during arctic winter and spring 1988, Geophys. Res. Lett., 15, 891–894, 1988. Pougatchev,~N S. and Rinsland,~C P.: Spectroscopic study of the seasonal variation of carbon monoxide vertical distribution above Kitt Peak, J Geophys. Res., 100, 1409–1416, 1995. Revell,~L E., Bodeker,~G E., Smale,~D., Lehmann,~R., Huck,~P E., Williamson,~B E., Rozanov,~E., and Struthers,~H.: The effectiveness of \chemN_2O in depleting stratospheric ozone, Geophys. Res. Lett., 39, L15806, http://dx.doi.org/10.1029/2012GL052143doi:10.1029/2012GL052143, 2012. Rinsland,~C P., Weisenstein,~D K., Ko,~M K W., Scott,~C J., Chiou,~L S., Mahieu,~E., Zander,~R., and Demoulin,~P.: Post Mount Pinatubo eruption ground-based stratospheric column measurements of \chemHNO_3, NO, and \chemNO_2 and their comparison with model calculation, J Geophys. Res., 108, 4437, http://dx.doi.org/10.1029/2002JD002965doi:10.1029/2002JD002965, 2003a. Rinsland,~C P., Mahieu,~E., Zander,~R., Jones,~N B., Chipperfield,~M P., Goldman,~A., Anderson,~J., Russell III,~J M., Demoulin,~P., Notholt,~J., Toon,~G C., Blavier,~J.-F., Sen,~B., Sussmann,~R., Wood,~S W., Meier,~A., Griffith,~D W T., Chiou,~L S., Murcray,~F J., Stephen,~T M., Hase,~F., Mikuteit,~S., Schulz,~A., and Blumenstock,~T.: Long-term trends of inorganic chlorine from ground-based infrared solar spectra: past increases and evidence for stabilization, J Geophys. Res., 108, 4252, http://dx.doi.org/10.1029/2002JD003001doi:10.1029/2002JD003001, 2003b. Rosenfield,~J E. and Douglass,~A R.: Doubled \chemCO_2 effects on \chemNO_y in a coupled 2-D model, Geophys. Res. Lett., 25, 4381–4384, 1998. Rothman, L. S., Jacquemart, D., Barbe, A., Chris Benner, D. Birk, M., Brown, L. R., Carleer, M. R., Chackerian Jr., C., Chance, K., Coudert, L. H., Dana, V., Devi, V. M., Gamache, R. R., Goldman, A., Jucks, K. W., Maki, A. G., Massie, S. T., Orphal, J., Perrin, A., Rinsland, C. P., Smith, M. A. H., Tennyson, J., Tolchenov, Toth, R. A., Vander Auwera, J., Varanasi, P., and Wagner, G.: The HITRAN 2004 molecular spectroscopic database, J Quant. Spectrosc. Ra., 96, 139–204, 2005. Santer,~B D., Wigley,~T M L., Boyle,~J S., Gaffen,~D J., Hnilo,~J J., Nychka,~D., Parker,~D E., and Taylor,~K E.: Statistical significance of trends and trend differences in layer-average atmospheric temperature time series, J Geophys. Res., 105, 7337–7356, 2000. Shettle,~E P.: Models of aerosols, clouds, and precipitation for atmospheric propagation studies, in: NATO AGARD Conference Proceedings No. 454: atmospheric propagation in the UV, visible, IR and mm-region and related system aspects, NATO (North Atlantic Treaty Organisation), Neuilly sur Seine, France, 1989. Solomon,~S.: Stratospheric ozone depletion: a review of concepts and history, Rev. Geophys., 37, 275–316, 1999. Vandaele,~A C., Hermans,~C., Simon,~P C., Carleer,~M., Colin,~R., Fally,~S., Mérienne,~M.-F., Jenouvrier,~A., and Coquart,~B.: Measurements of the \chemNO_2 absorption cross section from 42 000 \unitcm^-1 to 10000 \unitcm^-1 (238–1000 \unitnm) at 220 \unitK and 294 \unitK, J Quant. Spectrosc. Ra., 59, 171–184, 1998. van der A,~R J., Peters,~D H M U., Heskes,~H., Boersma,~K F., Van Roozendael,~M., De Smedt,~I., and Kelder,~H.: Detection of the trend and seasonal variation in tropospheric \chemNO_2 over China, J Geophys. Res., 111, D12317, http://dx.doi.org/10.1029/2005JD006594doi:10.1029/2005JD006594, 2006. Van Roozendael,~M., De Mazière,~M., and Simon,~P C.: Ground-based visible measurements at the Jungfraujoch station since 1990, J Quant. Spectrosc. Ra., 52, 231–240, 1994. Vernier,~J.-P., Thomason,~L W., Pommereau,~J.-P., Bourassa,~A., Pelon,~J., Garnier,~A., Hauchecorne,~A., Blanot,~L., Trepte,~C., Degenstein,~D., and Vargas,~F.: Major influence of tropical volcanic eruptions on the stratospheric aerosol layer during the last decade, Geophys. Res. Lett., 38, L12807, http://dx.doi.org/10.129/2011GL047563doi:10.129/2011GL047563, 2011. Vigouroux,~C., De~Mazière,~M., Errera,~Q., Chabrillat,~S., Mahieu,~E., Duchatelet,~P., Wood,~S., Smale,~D., Mikuteit,~S., Blumenstock,~T., Hase,~F., and Jones,~N.: Comparisons between ground-based FTIR and MIPAS N<sub>2</sub>O and \chemHNO_3 profiles before and after assimilation in BASCOE, Atmos. Chem. Phys., 7, 377–396, http://dx.doi.org/10.5194/acp-7-377-2007doi:10.5194/acp-7-377-2007, 2007. Vigouroux,~C., De~Mazière,~M., Demoulin,~P., Servais,~C., Hase,~F., Blumenstock,~T., Kramer,~I., Schneider,~M., Mellqvist,~J., Strandberg,~A., Velazco,~V., Notholt,~J., Sussmann,~R., Stremme,~W., Rockmann,~A., Gardiner,~T., Coleman,~M., and Woods,~P.: Evaluation of tropospheric and stratospheric ozone trends over Western Europe from ground-based FTIR network observations, Atmos. Chem. Phys., 8, 6865–6886, http://dx.doi.org/10.5194/acp-8-6865-2008doi:10.5194/acp-8-6865-2008, 2008. Weatherhead,~E C., Reinsel,~G C., Tiao,~G C., Meng,~X., Choi,~D., Cheang,~W., Keller,~T., DeLuisi,~J., Wuebbles,~D J., Kerr,~J B., Miller,~A J., Oltmans,~S J., and Frederick,~J E.: Factors affecting the detection of trends: statistical considerations and applications to environmental data, J Geophys. Res., 103, 17149–17161, 1998. WMO (World Meteorological Organization): Scientific Assessment of Ozone depletion: 2006 (chapt 4), Global Ozone Research and Monitoring Project, Report 50, World Meteorological Organization, Geneva, Switzerland, 2007. WMO (World Meteorological Organization): Scientific Assessment of Ozone depletion: 2010 (chapt 1), Global Ozone Research and Monitoring Project, Report 52, World Meteorological Organization, Geneva, Switzerland, 2011a. WMO (World Meteorological Organization): Scientific Assessment of Ozone depletion: 2010 (chapt 2), Global Ozone Research and Monitoring Project, Report 52, World Meteorological Organization, Geneva, Switzerland, 2011b. Wolff,~M A., Kerzenmacher,~T., Strong,~K., Walker,~K A., Toohey,~M., Dupuy,~E., Bernath,~P F., Boone,~C D., Brohede,~S., Catoire,~V., von~Clarmann,~T., Coffey,~M., Daffer,~W H., De~Mazière,~M., Duchatelet,~P., Glatthor,~N., Griffith,~D W T., Hannigan,~J., Hase,~F., Höpfner,~M., Huret,~N., Jones,~N., Jucks,~K., Kagawa,~A., Kasai,~Y., Kramer,~I., Küllmann,~H., Kuttippurath,~J., Mahieu,~E., Manney,~G., McElroy,~C T., McLinden,~C., Mébarki,~Y., Mikuteit,~S., Murtagh,~D., Piccolo,~C., Raspollini,~P., Ridolfi,~M., Ruhnke,~R., Santee,~M., Senten,~C., Smale,~D., Tétard,~C., Urban,~J., and Wood,~S.: Validation of \chemHNO_3, \chemClONO_2, and \chemN_2O_5 from the Atmospheric Chemistry Experiment Fourier Transform Spectrometer (ACE-FTS), Atmos. Chem. Phys., 8, 3529–3562, http://dx.doi.org/10.5194/acp-8-3529-2008doi:10.5194/acp-8-3529-2008, 2008. Zander,~R., Mahieu,~E., Demoulin,~P., Duchatelet,~P., Roland,~G., Servais,~C., De Mazière,~M., Reimann,~S., and Rinsland,~C P.: Our changing atmosphere: evidence based on long-term infrared solar observations at the Jungfraujoch since 1950, Sci. Total Environ., 391, 184–195 http://dx.doi.org/10.1016/j.scitotenv.2007.10.018doi:10.1016/j.scitotenv.2007.10.018, 2008.