References

ACP

Atmospheric Chemistry and Physics

ACP

1680-7324

Copernicus GmbH

Göttingen, Germany

10.5194/acp-8-3529-2008

Validation of HNO3, ClONO2, and N2O5 from the Atmospheric Chemistry Experiment Fourier Transform Spectrometer (ACE-FTS)

Wolff

M. A.

¹ Kerzenmacher

¹ Strong

¹ Walker

K. A.

¹ ² Toohey

¹ Dupuy

² Bernath

P. F.

² ³ Boone

C. D.

² Brohede

⁴ Catoire

⁵ von Clarmann

⁶ Coffey

⁷ Daffer

W. H.

⁸ De Mazière

⁹ Duchatelet

¹⁰ Glatthor

⁶ Griffith

D. W. T.

¹¹ Hannigan

⁷ Hase

⁶ Höpfner

⁶ Huret

⁵ Jones

¹¹ Jucks

¹² Kagawa

¹³ ¹⁴ Kasai

¹⁴ Kramer

⁶ Küllmann

¹⁵ Kuttippurath

¹⁵ ²⁴ Mahieu

¹⁰ Manney

¹⁶ ¹⁷ McElroy

C. T.

¹⁸ McLinden

¹⁸ Mébarki

⁵ Mikuteit

⁶ Murtagh

⁴ Piccolo

¹⁹ Raspollini

²⁰ Ridolfi

²¹ Ruhnke

⁶ Santee

¹⁶ Senten

⁹ Smale

²² Tétard

²³ Urban

⁴ Wood

²²

Department of Physics, University of Toronto, Toronto, Ontario, Canada

Department of Chemistry, University of Waterloo, Waterloo, Ontario, Canada

Department of Chemistry, University of York, York, UK

Department of Radio and Space Science, Chalmers University of Technology, Gothenburg, Sweden

Laboratoire de Physique et Chimie de L'Environment CNRS – Université d'Orléans, Orléans, France

Forschungzentrum Karlsruhe and Univ. of Karlsruhe, Institute for Meteorology and Climate Research, Karlsruhe, Germany

National Center for Atmospheric Research (NCAR), Boulder, CO, USA

Columbus Technologies Inc., Pasadena, CA, USA

Belgian Institute for Space Aeronomy, Brussels, Belgium

Institute of Astrophysics and Geophysics, University of Liège, Liège, Belgium

School of Chemistry, University of Wollongong, Wollongong, Australia

Harvard-Smithsonian Center for Astrophysics, Cambridge, MA, USA

Fujitsu FIP Corporation, Tokyo, Japan

Environmental Sensing and Network Group, National Institute of Information and Communications Technology (NICT), Tokyo, Japan

Institute of Environmental Physics, University of Bremen, Bremen, Germany

Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA, USA

New Mexico Institute of Mining and Technology, Socorro, NM, USA

Environment Canada, Toronto, Ontario, Canada

Atmospheric, Oceanic and Planetary Physics, University of Oxford, Oxford, UK

Institute of Applied Physics "Nello Carrara", National Research Center (CNR), Firenze, Italy

Dipartimento di Chimica Fisica e Inorganica, Università di Bologna, Bologna, Italy

National Institute of Water and Atmospheric Research Ltd., Central Otago, New Zealand

Laboratoire d'Optique Atmosphérique, Université des Sciences et Technologies de Lille, Villeneuve d'Ascq, France

now at: LMD/CNRS Ecole polytechnique, Palaiseau Cedex, France

07 07 2008

8 13 3529 3562

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/8/3529/2008/acp-8-3529-2008.html

The full text article is available as a PDF file from http://www.atmos-chem-phys.net/8/3529/2008/acp-8-3529-2008.pdf

The Atmospheric Chemistry Experiment (ACE) satellite was launched on 12 August 2003. Its two instruments measure vertical profiles of over 30 atmospheric trace gases by analyzing solar occultation spectra in the ultraviolet/visible and infrared wavelength regions. The reservoir gases HNO3, ClONO2, and N2O5 are three of the key species provided by the primary instrument, the ACE Fourier Transform Spectrometer (ACE-FTS). This paper describes the ACE-FTS version 2.2 data products, including the N2O5 update, for the three species and presents validation comparisons with available observations. We have compared volume mixing ratio (VMR) profiles of HNO3, ClONO2, and N2O5 with measurements by other satellite instruments (SMR, MLS, MIPAS), aircraft measurements (ASUR), and single balloon-flights (SPIRALE, FIRS-2). Partial columns of HNO3 and ClONO2 were also compared with measurements by ground-based Fourier Transform Infrared (FTIR) spectrometers. Overall the quality of the ACE-FTS v2.2 HNO3 VMR profiles is good from 18 to 35 km. For the statistical satellite comparisons, the mean absolute differences are generally within ±1 ppbv ±20%) from 18 to 35 km. For MIPAS and MLS comparisons only, mean relative differences lie within±10% between 10 and 36 km. ACE-FTS HNO3 partial columns (~15–30 km) show a slight negative bias of −1.3% relative to the ground-based FTIRs at latitudes ranging from 77.8° S–76.5° N. Good agreement between ACE-FTS ClONO2 and MIPAS, using the Institut für Meteorologie und Klimaforschung and Instituto de Astrofísica de Andalucía (IMK-IAA) data processor is seen. Mean absolute differences are typically within ±0.01 ppbv between 16 and 27 km and less than +0.09 ppbv between 27 and 34 km. The ClONO2 partial column comparisons show varying degrees of agreement, depending on the location and the quality of the FTIR measurements. Good agreement was found for the comparisons with the midlatitude Jungfraujoch partial columns for which the mean relative difference is 4.7%. ACE-FTS N2O5 has a low bias relative to MIPAS IMK-IAA, reaching −0.25 ppbv at the altitude of the N2O5 maximum (around 30 km). Mean absolute differences at lower altitudes (16–27 km) are typically −0.05 ppbv for MIPAS nighttime and ±0.02 ppbv for MIPAS daytime measurements.

References 1

Abrams, M C., Chang, A Y., Gunson, M R., Abbas, M M., Goldman, A., Irion, F W., Michelsen, H A., Newchurch, M J., Rinsland, C P., Stiller, G P., and Zander, R.: On the assessment and uncertainty of atmospheric trace gas burden measurements with high resolution infrared solar occultation spectra from space by the ATMOS experiment, Geophys. Res. Lett., 23, 2337–2340, \doi10.1029/96GL01794, 1996.

Barret, B., Ricaud, P., Santee, M L., Attié, J.-L., Urban, J., Flochmo\"en, E L., Berthet, G., Murtagh, D., Eriksson, P., Jones, A., de~La~No\"e, J., Dupuy, E., Froidevaux, L., Livesey, N J., Waters, J W., and Filipiak, M J.: Intercomparisons of trace gas profiles from the Odin/SMR and Aura/MLS limb sounders, J. Geophys. Res., 111, D21302, \doi10.1029/2006JD007305, 2006.

Bernath, P F.: Atmospheric chemistry experiment (ACE): Analytical chemistry from orbit, Trends in Anal. Chem., 5, 647–654, 2006.

Bernath, P F., McElroy, C T., Abrams, M C., Boone, C D., Butler, M., Camy-Peyret, C., Carleer, M., Clerbaux, C., Coheur, P F., Colin, R., DeCola, P., Mazière, M D., Drummond, J R., Dufour, D., Evans, W. F J., Fast, H., Fussen, D., Gilbert, K., Jennings, D E., Llewellyn, E J., Lowe, R P., Mahieu, E., McConnel, J C., McHugh, M., McLeod, S D., Michaud, R., Midwinter, C., Nassar, R., Nichitu, F., Nowlan, C., Rinsland, C P., Rochon, Y J., Rowlands, N., Semeniuk, K., Simon, P., Skelton, R., Sloan, J J., Soucy, M A., Strong, K., Tremblay, P., Turnbull, D., Walker, K A., Walkty, I., Wardle, D A., Wehrle, V., Zander, R., and Zou, J.: Atmospheric Chemistry Experiment (ACE): Mission overview, Geophys. Res. Lett., 32, L15S01, \doi10.1029/2005GL022386, 2005.

Bingham, G E., Zhou, D K., Bartschi, B Y., Anderson, G P., Smith, D R., Chetwynd, J H., and Nadile, R M.: Cryogenic Infrared Radiance Instrumentation for Shuttle (CIRRIS 1A) Earth limb spectral measurements, calibration, and atmospheric O3, HNO3, CFC-12, and CFC-11 profile retrieval, J. Geophys. Res., 102, 3547–3558, 1997.

Blumenstock, T., Kopp, G., Hase, F., Hochschild, G., Mikuteit, S., Raffalski, U., and Ruhnke, R.: Observation of unusual chlorine activation by ground-based infrared and microwave spectroscopy in the late Arctic winter 2000/2001, Atmos. Chem. Phys., 6, 897–905, 2006.

Boone, C D., Nassar, R., Walker, K A., Rochon, Y J., McLeod, S D., Rinsland, C P., and Bernath, P F.: Retrievals for the Atmospheric Chemistry Experiment Fourier-Transform Spectrometer, Appl. Optics, 44, 7218–7231, 2005.

Brasseur, G P. and Solomon, S.: Aeronomy of the Middle Atmosphere, Springer, Dordrecht, 3rd ed., XII, pp. 646, The Netherlands, 2005.

Canty, T., Pickett, H M., Salawitch, R J., Jucks, K W., Traub, W A., and Waters, J W.: Stratospheric and mesospheric HOx: Results from Aura MLS and FIRS-2, Geophys. Res. Lett., 33, L12802, doi:10.1029/2006GL025964, 2006.

Carli, B., Alpaslan, D., Carlotti, M., Castelli, E., Ceccherini, S., Dinelli, B M., Dudhia, A., Flaud, J M., Höpfner, M., Jay, V., Magnani, L., Oelhaf, H., Payne, V., Piccolo, C., Prosperi, M., Raspollini, P., Remedios, J., Ridolfi, M., and Spang, R.: First results of MIPAS/ENVISAT with operational Level 2 code, Adv. Space Res., 33, 1012–1019, 2004.

Dessler, A.: The Chemistry and Physics of Stratospheric Ozone, International Geophysics Series, Academic Press, Cornwall, IX, 214 pp., UK, 2000.

Draxler, R R. and Hess, G D.: An Overview of the Hysplit_4 Modeling System for Trajectories, Dispersion, and Deposition, Aust. Met. Mag., 47, 295–308, 1998a.

Draxler, R R. and Hess, G D.: Description of the Hysplit_4 modeling system, Tech. Rep. ERL ARL-224, NOAA, 1998b.

Dunkerton, T J. and Delisi, D P.: Evolution of potential vorticity in the winter stratosphere of January–February 1979, J. Geophys. Res., 91, 1199–1208, 1986.

Dupuy, E., Walker, K A., Kar, J., Boone, C D., McElroy, C T., Bernath, P F., Drummond, J R., Skelton, R., McLeod, S D., Hughes, R C., Nowlan, C R., Dufour, D G., Zou, J., Nichitiu, F., Strong, K., Baron, P., Bevilacqua, R M., Blumenstock, T., Bodeker, G E., Borsdorff, T., Bourassa, A E., Bovensmann, H., Boyd, I S., Bracher, A., Brogniez, C., Burrows, J P., Catoire, V., Ceccherini, S., Chabrillat, S., Christensen, T., Coffey, M T., Cortesi, U., Davies, J., Clercq, C D., Degenstein, D A., Mazière, M D., Demoulin, P., Dodion, J., Firanski, B., Fischer, H., Forbes, G., Froidevaux, L., Fussen, D., Gerard, P., Godin-Beekman, S., Goutail, F., Granville, J., Griffith, D., Haley, C S., Hannigan, J W., Höpfner, M., Jin, J J., Jones, A., Jones, N B., Jucks, K., Kagawa, A., Kasai, Y., Kerzenmacher, T E., Kleinböhl, A., Klekociuk, A R., Kramer, I., Küllmann, H., Kuttippurath, J., Kyrölä, E., Lambert, J C., Livesey, N J., Llewellyn, E J., Lloyd, N D., Mahieu, E., Manney, G L., Marshall, B T., McConnell, J C., McCormick, M P., McDermid, I S., McHugh, M., McLinden, C A., Mellqvist, J., Mizutani, K., Murayama, Y., Murtagh, D P., Oelhaf, H., Parrish, A., Petelina, S V., Piccolo, C., Pommereau, J P., Randall, C E., Robert, C., Roth, C., III, J. M R., Schneider, M., Senten, C., Steck, T., Strandberg, A., Strawbridge, K B., Sussmann, R., Swart, D. P J., Tarasick, D W., Taylor, J R., Tétard, C., Thomason, L W., Thompson, A M., Tully, M B., Urban, J., Vanhellemont, F., von Clarmann, T., von~der Gathen, P., von Savigny, C., Waters, J W., Witte, J C., Wolff, M., and Zawodny, J M.: Validation of ozone measurements from the Atmospheric Chemistry Experiment (ACE), Atmos. Chem. Phys. Discuss., 8, 2513–2656, 2008.

Fischer, H., Birk, M., Blom, C., Carli, B., Carlotti, M., von Clarmann, T., Delbouille, L., Dudhia, A., Ehhalt, D., Endemann, M., Flaud, J M., Gessner, R., Kleinert, A., Koopmann, R., Langen, J., López-Puertas, M., Mosner, P., Nett, H., Oelhaf, H., Perron, G., Remedios, J., Ridolfi, M., Stiller, G., and Zander, R.: MIPAS: an instrument for atmospheric and climate research, Atmos. Chem. Phys., 8, 2151–2188, 2008.

Froidevaux, L., Livesey, N J., Read, W G., Jiang, Y B., Jimenez, C., Filipiak, M J., Schwartz, M J., Santee, M L., Pumphrey, H C., Jiang, J H., Wu, D L., Manney, G L., Drouin, B J., Waters, J W., Fetzer, E J., Bernath, P F., Boone, C D., Walker, K A., Jucks, K W., Toon, G C., Margitan, J J., Sen, B., Webster, C R., Christensen, L E., Elkins, J W., Atlas, E., Lueb, R A., and Hendershot, R.: Early validation analyses of atmospheric profiles from EOS MLS on the Aura Satellite, IEEE Trans. Geosci. Remote Sension, 44, 1106–1121, 2006.

Gilbert, K L., Turnbull, D N., Walker, K A., Boone, C D., McLeod, S D., Butler, M., Skelton, R., Bernath, P F., Chateauneuf, F., and Soucy, M A.: The onboard imagers for the Canadian ACE SCISAT-1 mission, J. Geophys. Res., 112, D12207, \doi10.1029/2006JD007714, 2007.

Gille, J C. and Russell, J M.: The Limb Infrared Monitor of the Stratosphere: Experiment description, performance, and results, J. Geophys. Res., 89, 5125–5140, 1984.

Gille, J C., Bailey, P L., Gandrud, B W., Russell, J M., Remsberg, E E., Gordley, L L., Evans, W. F J., Fischer, H., Girard, A., and Harrison, J E.: Accuracy and precision of the nitric acid concentrations determined by the Limb Infrared Monitor of the Stratosphere experiment on Nimbus 7, J. Geophys. Res., 89, 5179–5190, 1984.

Gille, J C., Barnett, J J., Arter, P., Barker, M., Bernath, P F., Boone, C D., Cavanaugh, C., Chow, J., Coffey, M., Craft, J., Craig, C., Dials, M., Dean, V., Eden, T., Edwards, D P., Francis, G., Halvorson, C., Harvey, L., Hepplewhite, C., Kinnison, D., Khosravi, R., Krinsky, C., Lambert, A., Lyjak, L., Lee, H., Loh, J., Mankin, W G., McInnerney, J., Moorhous, J., Massie, S., Nardi, B., Packman, D., Randall, C E., Reburn, J., Rudolf, W., Schwartz, M J., Serafin, J., Stone, K., Torpy, B., Walker, K A., Waterfall, A., Watkins, R., Whitney, J G., Woodard, D., and Young, G.: The High Resolution Dynamics Limb Sounder (HIRDLS) Experiment Overview, Results and Temperature Validation, J. Geophys. Res., 113, D16543, \doi10.1029/2007JD008824, 2008.

Goldman, A., Paton-Walsh, C., Bell, W., Toon, G C., Blavier, J F., Sen, B., Coffey, M T., Hannigan, J W., and Mankin, W G.: Network for the Detection of Stratospheric Change Fourier transform infrared intercomparison at Table Mountain Facility, J. Geophys. Res., 104, 30 481–30 504, 1999.

Griffith, D. W T., Jones, N B., McNamara, B., Paton-Walsh, C., Bell, W., and Bernardo, C.: Intercomparison of ground-based solar FTIR measurements of atmospheric gases at Lauder, New Zealand, J. Atmos. Oceanic Technol., 20, 1138–1153, 2003.

Gunson, M R., Abbas, M M., Abrams, M C., Allen, M., Brown, L R., Brown, T L., Chang, A Y., Goldman, A., Irion, F W., Lowes, L L., Mahieu, E., Manney, G L., Michelsen, H A., Newchurch, M J., Rinsland, C P., Salawitch, R J., Stiller, G P., Toon, G C., Yung, Y L., and Zander, R.: The Atmospheric Trace Molecule Spectroscopy (ATMOS) experiment: Deployment on the ATLAS Space Shuttle missions, Geophys. Res. Lett., 23, 2333–2336, 1996.

Hase, F.: Inversion von Spurengasprofilen aus hochaufgelösten bodengebundenen FTIR-Messungen in Absorption – Retrieval of trace gas profiles from high resolution, ground based FTIR-measurements in absorption, 6512, FZKA Wissenschaftliche Berichte – Scientific Reports, Forschungszentrum Karlsruhe, 2000.

Hase, F., Hannigan, J W., Coffey, M T., Goldman, A., Höpfner, M., Jones, N B., Rinsland, C P., and Wood, S W.: Intercomparison of retrieval codes used for the analysis of high-resolution, ground-based FTIR measurements, J. Quant. Spectrosc. Radiat. Transfer, 87, 25–52, \doi10.1016/j.jqsrt.2003.12.008, 2004.

Hauchecorne, A., Godin, S., Marchand, M., Heese, B., and Souprayen, C.: Quantification of the transport of chemical constituents from the polar vortex to midlatitudes in the lower stratospher using the high-resolution advection model MIMOSA and effective diffusivity, J. Geophys. Res., 107, 8289, \doi10.1029/2001JD000491, 2002.

Hofmann, D J. and Solomon, S.: Ozone destruction through heterogeneous chemistry following the eruption of El Chichón, J. Geophys. Res., 94, 5029–5041, 1989.

Höpfner, M., von Clarmann, T., Fischer, H., Funke, B., Glatthor, N., Grabowski, U., Kellmann, S., Kiefer, M., Linden, A., Milz, M., Steck, T., Stiller, G P., Bernath, P F., Blom, C E., Blumenstock, T., Boone, C., Chance, K., Coffey, M T., Friedl-Vallon, F., Griffith, D., Hannigan, J W., Hase, F., Jones, N., Jucks, K W., Keim, C., Kleinert, A., Kouker, W., Liu, G Y., Mahieu, E., Mellqvist, J., Mikuteit, S., Notholt, J., Oelhaf, H., Piesch, C., Reddmann, T., Ruhnke, R., Schneider, M., Strandberg, A., Toon, G., Walker, K A., Warneke, T., Wetzel, G., Wood, S., and Zander, R.: Validation of MIPAS ClONO2 measurements, Atmos. Chem. Phys., 7, 281, 2007.

Irie, H., Kondo, Y., Koike, M., Danilin, M Y., Camy-Peyret, C., Payan, S., Pommereau, J P., Goutail, F., Oelhaf, H., Wetzel, G., Toon, G C., Sen, B., Bevilacqua, R M., III, J. M R., Renard, J B., Kanzawa, H., Nakajima, H., Yokota, T., Sugita, T., and Sasano, Y.: Validation of NO2 and HNO3 measurements from the Improved Limb Atmospheric Spectrometer (ILAS) with the version 5.20 retrieval algorithm, J. Geophys. Res., 107, 8206, \doi10.1029/2001JD001304, 2002.

Irie, H., Sugita, T., Nakajima, H., Yokota, T., Oelhaf, H., Wetzel, G., Toon, G C., Sen, B., Santee, M L., Terao, Y., Saitoh, N., Ejiri, M K., Tanaka, T., Kondo, Y., Kanzawa, H., Kobayashi, H., and Sasano, Y.: Validation of stratospheric nitric acid profiles observed by Improved Limb Atmospheric Spectrometer (ILAS)-II, J. Geophys. Res., 111, D11S03, \doi10.1029/2005JD006115, 2006.

Irion, F W., Gunson, M R., Toon, G C., Chang, A Y., Eldering, A., Mahieu, E., Manney, G L., Michelsen, H A., Moyer, E J., Newchurch, M J., Osterman, G B., Rinsland, C P., Salawitch, R J., Sen, B., Yung, Y L., and Zander, R.: Atmospheric Trace Molecule Spectroscopy (ATMOS) Experiment Version 3 data retrievals, Appl. Optics, 41, 6968–6979, 2002.

Johnson, D G., Jucks, K W., Traub, W A., and Chance, K V.: Smithsonian stratospheric far-infrared spectrometer and data reduction system, J. Geophys. Res., 100, 3091–3106, \doi10.1029/94JD02685, 1995.

Jucks, K W., Johnson, D G., Chance, K V., Traub, W A., Margitan, J M., Stachnik, R., Sasano, Y., Yokota, T., Kanzawa, H., Shibasaki, K., Suzuki, M., and Ogawa, T.: Validation of ILAS v5.2 data with FIRS-2 balloon observations, J. Geophys. Res., 107, 8207, \doi10.1029/2001JD000578, 2002.

Kasai, Y J., Kagawa, A., Jones, N., Fujiwara, A., Seki, K., Murayama, Y., and Murcray, F.: Seasonal variations of CO and HCN in the troposphere measured by solar absorption spectroscopy over Poker Flat, Alaska, Geophys. Res. Lett., 32, L19812, \doi10.1029/2005GL022826, 2005.

Kerzenmacher, T., Wolff, M A., Strong, K., Dupuy, E., Walker, K A., Amekudzi, L K., Batchelor, R L., Bernath, P F., Berthet, G., Blumenstock, T., Boone, C D., Bramstedt, K., Brogniez, C., Brohede, S., Burrows, J P., Catoire, V., Dodion, J., Drummond, J R., Dufour, D G., Funke, B., Fussen, D., Goutail, F., Griffith, D. W T., Haley, C S., Hendrick, F., Höpfner, M., Huret, N., Jones, N B., Kar, J., Kramer, I., Llewellyn, E J., López-Puertas, M., Manney, G L., McElroy, C T., McLinden, C A., Melo, S., Mikuteit, S., Murtagh, D P., Nichitiu, F., Notholt, J., Nowlan, C R., Piccolo, C., Pommereau, J P., Randall, C E., Richter, A., Schneider, M., Schrems, O., Silicani, M., Stiller, G P., Taylor, J R., Tétard, C., Toohey, M., Vanhellemont, F., Warneke, T., Zawodny, J M., and Zou, J.: Validation of NO2 and NO from the Atmospheric Chemistry Experiment (ACE), Atmos. Chem. Phys. Discuss., 8, 3027–3142, 2008.

King, P., McKinnon, I R., Mathieson, J G., and Wilson, I R.: Upper limit to stratospheric N2O$_5$ abundance, J. Atmos. Sci., 33, 1657–1659, 1976.

Kinnison, D E., Gille, J., Barnett, J., Randall, C., Harvey, L., Lambert, A., Khosravi, R., Alexander, M J., Bernath, P F., Boone, C D., Cavanaugh, C., Coffey, M., Craig, C., Dean, V C., Eden, T., Ellis, D., Fahey, D W., Francis, G., Halvorson, C., Hannigan, J., Hartsough, C., Hepplewhite, C., Krinsky, C., Lee, H., Mankin, B., Marcy, T P., Massie, S., Nardi, B., Packman, D., Popp, P J., Santee, M L., and Walker, K A.: Global Observations of HNO3 from the High Resolution Dynamics Limb Sounder (HIRDLS) - First results, J. Geophys. Res., 113, D16544, \doi10.1029/2007JD008814, 2008.

Kleinböhl, A., Bremer, H., von König, M., Küllmann, H., Künzi, K., Goede, A. P H., v Browell, E., Grant, W B., Toon, G C., Blumenstock, T., Galle, B., Sinnhuber, B M., and Davies, S.: Vortexwide denitrification of the Arctic polar stratosphere in winter 1999/2000 determined by remote observations, J. Geophys. Res., 108, \doi10.1029/2001JD001042, 2003.

Kleinböhl, A., Bremer, H., Küllmann, H., Kuttippurath, J., Browell, E V., Canty, T., Salawitch, R J., Toon, G C., and Notholt, J.: Denitrification in the Arctic mid-winter 2004/2005 observed by airborne submillimeter radiometry, Geophys. Res. Lett., 32, \doi10.1029/2005/Gl023408, 2005.

Koike, M., Kondo, Y., Irie, H., Murcray, F J., Williams, J., Fogal, P., Blatherwick, R., Camy-Peyret, C., Payan, S., Oelhaf, H., Wetzel, G., Traub, W., Johnson, D., Jucks, K., Toon, G C., Sen, B., Blavier, J F., Schlager, H., Ziereis, H., Toryama, N., Danilin, M Y., Rodriguez, J M., Kanzawa, H., and Sasano, Y.: A comparison of Arctic HNO3 profiles measured by the Improved Limb Atmospheric Spectrometer and balloon-borne sensors., J. Geophys. Res., 105, 6761–6771, 2000.

Kouker, W., Langbein, I., Reddmann, T., and Ruhnke, R.: The Karlsruhe simulation model of the middle atmosphere (KASIMA), version 2, 6278, FZKA Wissenschaftliche Berichte – Scientific Reports\/, Forschungszentrum Karlsruhe, 1999.

Kumer, J B., Mergenthaler, J L., Roche, A E., Nightingale, R W., Ely, G A., Uplinger, W G., Gille, J C., Massie, S T., Bailey, P L., Gunson, M R., Abrams, M C., Toon, G C., Sen, B., Blavier, J., Stachnik, R A., Webster, C R., May, R D., Murcray, D G., Murcray, F J., Goldman, A., Traub, W A., Jucks, K W., and Johnson, D G.: Comparison of correlative data with HNO3 version 7 from the CLAES instrument deployed on the NASA Upper Atmosphere Research Satellite, J. Geophys. Res., 101, 9621–9656, \doi10.1029/95JD03759, 1996a.

Kumer, J B., Mergenthaler, J L., Roche, A E., Nightingale, R W., Zele, F., Gille, J C., Massie, S T., Bailey, P L., Connell, P S., Gunson, M R., Abrams, M C., Toon, G C., Sen, B., Blavier, J., Smith, S E., and Taylor, F W.: Comparison of CLAES preliminary N2O$_5$ data with correlative data and a model, J. Geophys. Res., 101, 9657–9677, 1996b.

Kumer, J B., Kawa, S R., Roche, A E., Mergenthaler, J L., Smith, S E., Taylor, F W., Connell, P S., and Douglass, A R.: UARS first global N2O$_5$ data sets: Application to a stratospheric warming event in January 1992, J. Geophys. Res., 102, 3575–3582, 1997.

Lefèvre, F., Figarol, F., Carslaw, K., and Peter, T.: The 1997 Arctic ozone depletion quantified from three-dimensional model simulations, Geophys. Res. Lett., 25, 2425–2428, 1998.

Livesey, N J., Snyder, W V., Read, W G., and Wagner, P A.: Retrieval algorithms for the EOS Microwave limb sounder (MLS), IEEE Trans. Geosci. Remote Sens., 44, 1144–1155, \doi10.1109/TGRS.2006.872327, 2006.

Livesey, N J., Read, W G., Lambert, A., Cofield, R E., Cuddy, D T., Froidevaux, L., Fuller, R A., Jarnot, R F., Jiang, J H., Jiang, Y B., Knosp, B W., Kovalenko, L J., Pickett, H M., Pumphrey, H C., Santee, M L., Schwartz, M J., Stek, P C., Wagner, P A., Waters, J W., and Wu, D L.: Earth Observing System (EOS)– Aura Microwave Limb Sounder (MLS), Version 2.2 Level 2 data quality and description document, Tech. Rep. JPL D-33509, Jet Propulsion Laboratory, California Institute of Technology, 2007.

Mahieu, E., Zander, R., Delbouille, L., Demoulin, P., Roland, G., C., and Servais: Observed trends in total vertical column abundances of atmospheric gases from IR solar spectra recorded at the Jungfraujoch, J. Atmos. Chem., 28, 227–243, 1997.

Mahieu, E., Zander, R., Duchatelet, P., Hannigan, J W., Coffey, M T., Mikuteit, S., Hase, F., Blumenstock, T., Wiacek, A., Strong, K., Taylor, J R., Mittermeier, R L., Fast, H., Boone, C D., McLeod, S D., Walker, K A., Bernath, P F., and Rinsland, C P.: Comparisons between ACE-FTS and ground-based measurements of stratospheric HCL and ClONO2 loadings at northern latitudes, Geophys. Res. Lett., 32, L15S08, \doi10.1029/2005GL022396, 2005.

Manney, G L., Zurek, R W., O'Neill, A., and Swinbank, R.: On the motion of air through the stratospheric polar vortex, J. Atmos. Sci., 51, 2973–2994, 1994.

McElroy, C T., Nowlan, C R., Drummond, J R., Bernath, P F., Barton, D V., Dufour, D G., Midwinter, C., Hall, R B., Ogyu, A., Ullberg, A., Wardle, D I., Kar, J., Zou, J., Nichitiu, F., Boone, C D., Walker, K A., and Rowlands, N.: The ACE-MAESTRO instrument on SCISAT: Description, performance, and preliminary results, Appl. Optics, 46, 4341–4356, 2007.

McLinden, C A., Olsen, S C., Hannegan, B., Wild, O., Prather, M J., and Sundet, J.: Stratospheric ozone in 3-D models: A simple chemistry and the cross-tropopause flux, J. Geophys. Res., 105, 14 653–14 665, 2000.

Mengistu Tsidu, G., von Clarmann, T., Stiller, G P., Höpfner, M., Fischer, H., Glatthor, N., Grabowski, U., Kellmann, S., Kiefer, M., Linden, A., Milz, M., Steck, T., Wang, D Y., and Funke, B.: Stratospheric N2O$_5$ in the austral spring 2002 as retrieved from limb emission spectra recorded by the Michelson Interferometer for Passive Atmospheric Sounding (MIPAS), J. Geophys. Res., 109, D11301, \doi10.1029/2004JD004856, 2004.

Mengistu Tsidu, G., Stiller, G P., von Clarmann, T., Funke, B., Höpfner, M., Fischer, H., Glatthor, N., Grabowski, U., Kellmann, S., Kiefer, M., Linden, A., López-Puertas, M., Milz, M., Steck, T., and Wang, D Y.: NOy from Michelson Interferometer for Passive Atmospheric Sounding on Environmental Satellite during the Southern Hemisphere polar vortex split in September/October 2002., J. Geophys. Res., 110, D18301, \doi10.1029/2004JD005322, 2005.

Mergenthaler, J L., Kumer, J B., Roche, A E., Nightingale, R W., Potter, J F., Gille, J C., Massie, S T., Bailey, P L., Edwards, D., Connell, P S., Kinnison, D E., Gunson, M R., Abrams, M C., Toon, G C., Sen, B., Blavier, J F., Murcray, D G., Murcray, F J., and Goldman, A.: Validation of CLAES ClONO2 measurements, J. Geophys. Res., 101, 9603–9620, 1996.

Moreau, G., Robert, C., Catoire, V., Chartier, M., Camy-Peyret, C., Huret, N., Pirre, M., Pomathiod, L., and Chalumeau, G.: SPIRALE: a multispecies in situ balloon-borne instruments with six tunable diode laser spectrometers, Appl. Optics, 44, 5972–5989, 2005.

Murcray, D G., Kyle, T G., Murcray, F H., and Williams, W J.: Nitric acid and nitric oxide in the lower stratosphere, Nature, 218, 78–79, 1968.

Murcray, D G., Goldman, A., Murcray, F H., Murcray, F J., and Williams, W J.: Stratospheric distribution of ClONO2, Geophys. Res. Lett., 6, 857–859, 1979.

Murtagh, D., Frisk, U., Merino, F., Ridal, M., Jonsson, A., Stegman, J., Witt, G., Eriksson, P., Jiménez, C., Mégie, G., de~la Nöe, J., Ricaud, P., Baron, P., Pardo, J R., Hauchcorne, A., Llewellyn, E J., Degenstein, D A., Gattinger, R L., Lloyd, N D., Evans, W. F J., McDade, I C., Haley, C S., Sioris, C., von Savigny, C., Solheim, B H., McConnell, J C., Strong, K., Richardson, E H., Leppelmeier, G W., Kyrölä, E., Auvinen, H., and Oikarinen, L.: An overview of the Odin atmospheric mission, Can. J. Phys., 80, 309–319, 2002.

Nakajima, H., Suzuki, M., Matsuzaki, A., Ishigaki, T., Waragai, K., Mogi, Y., Kimura, N., Araki, N., Yokota, T., Kanzawa, H., Sugita, T., and Sasano, Y.: Characteristics and performance of the Improved Limb Atmospheric Spectrometer (ILAS) in orbit, J. Geophys. Res., 107, 8213, \doi10.1029/2001JD001439, 2002.

Nakajima, H., Sugita, T., Irie, H., Saitoh, N., Kanzawa, H., Oelhaf, H., Wetzel, G., Toon, G C., Sen, B., Blavier, J F., Traub, W A., Jucks, K., Johnson, D G., Yokota, T., Yokota, T., and Sasano, Y.: Measurements of ClONO2 by the Improved Limb Atmospheric Spectrometer (ILAS) in high-latitude stratosphere: New products using version 6.1 data processing algorithm, J. Geophys. Res., 111, D11S09, \doi10.1029/2005JD006441, 2006.

Nash, E R., Newman, P A., Rosenfield, J E., and Schoeberl, M R.: An objective determination of the polar vortex using Ertel's potential vorticity, J. Geophys. Res., 101, 9471–9478, 1996.

Offermann, D., Grossmann, K U., Barthol, P., Knieling, P., Riese, M., and Trant, R.: Cryogenic Infrared Spectrometers and Telescopes for the Atmosphere (CRISTA) experiment and middle atmosphere variability, J. Geophys. Res., 104, 16, 3251, 1999.

Oshchepkov, S., Sasano, Y., Yokota, T., Nakajima, H., Uemura, N., Saitoh, N., Sugita, T., and Matsuda, H.: ILAS data processing for stratospheric gas and aerosol retrievals with aerosol physical modeling: Methodology and validation of gas retrievals, J. Geophys. Res., 111, D02307, \doi10.1029/2005JD006543, 2006.

Paton-Walsh, C., Jones, N B., Wilson, S R., Haverd, V., Meier, A., Griffith, D. W T., and Rinsland, C P.: Measurements of trace gas emissions from Australian forest fires and correlations with coincident measurements of aerosol optical depth, J. Geophys. Res., 110, D24305, \doi24310.21029/22005JD006202, 2005.

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.

Pougatchev, N S., Connor, B J., and Rinsland, P. C.: Infrared measurements of the ozone vertical distribution above Kitt Peak, J. Geophys. Res., 100, 16 689–16 698, 1995.

Raspollini, P., Belotti, C., Burgess, A., Carli, B., Carlotti, M., Ceccherini, S., Dinelli, B M., Dudhia, A., Flaud, J M., Funke, B., Höpfner, M., López-Puertas, M., Payne, V., Piccolo, C., Remedios, J., Ridolfi, M., and Spang, R.: MIPAS level 2 operational analysis, Atmos. Chem. Phys., 6, 5605–5630, 2006.

Reisinger, A R., Jones, N B., Matthews, W A., and Rinsland, C P.: Southern hemisphere midlatitude ground-based measurements of ClONO2, J. Geophys. Res., 100, 23 183–23 194, \doi10.1029/95JD02529, 1995.

Renard, J B., Ovarlez, J., Berthet, G., Fussen, D., Vanhellemont, F., Brogniez, C., Hadamcik, E., Chartier, M., and Ovarlez, H.: Optical and physical properties of stratospheric aerosols from balloon measurements in the visible and near-infrared domains, 3. Presence of aerosols in the middle stratosphere, Appl. Opt., 44, 19, 4086–4095, 2005.

Renard, J B., Brogniez, C., Berthet, G., Bourgeois, Q., Gaubicher, B., Chartier, M., Balois, J.-Y., Verwaerde, C., Auriol, F., Fran�ois, P., and Daugeron, D.: Vertical distribution of the various natures of aerosols in the whole stratosphere, 1. Detection of liquid particles, interplanetary material and soot, and analysis of their spatial variability using the balloon-borne instruments STAC, SALOMON and Micro-RABIDAL, and the satellite instrument GOMOS-Envisat, J. Geophys. Res., in revision, 2008.

Ridolfi, M., Carli, B., Carlotti, M., von Clarmann, T., Dinelli, B., Dudhia, A., Flaud, J M., Höpfner, M., Morris, P E., Raspollini, P., Stiller, G., and Wells, R J.: Optimized forward and retrieval scheme for MIPAS near-real-time data processing, Appl. Optics, 39, 1323–1340, 2000. \bibitem[Ridolfi et~al.(2007)Ridolfi, Blum, Carli, Catoire, Ceccherini, Claude, De Clercq, Fricke, Friedl-Vallon, Iarlori, Keckhut, Kerridge, Lambert, Meijer, Mona, Oelhaf, Pappalardo, Pirre, Rizi, Robert, Swart, von Clarmann, Waterfall, and Wetzel] RefWorks:217 Ridolfi,M., Blum,U., Carli,B., Catoire,V., Ceccherini,S., Claude,H., De Clercq, C., Fricke,K.H., Friedl-Vallon, F., Iarlori,M., Keckhut,P., Kerridge,B., Lambert,J.-C., Meijer,Y.J., Mona,L., Oelhaf,H., Pappalardo,G., Pirre,M., Rizi,V., Robert,C., Swart,D., von Clarmann, T., Waterfall,A., and Wetzel,G.: Geophysical validation of temperature retrieved by the ESA processor from MIPAS/ENVISAT atmospheric limb-emission measurements, Atmos. Chem. Phys., 7, 16, 4459–4487, 2007.

Riese, M., Preusse, P., Spang, R., Ern, M., Jarisch, M., Grossmann, K U., and Offermann, D.: Measurements of trace gases by the Cryogenic Infrared Spectrometers and Telescopes for the Atmosphere (CRISTA) experiment, Adv. Space Res., 19, 563–566, 1997.

Riese, M., Spang, R., Preusse, P., Ern, M., Jarisch, M., Offermann, D., and Grossmann, K U.: Cryogenic Infrared Spectrometers and Telescopes for the Atmosphere (CRISTA) data processing and atmospheric temperature and trace gas retrieval, J. Geophys. Res., 104, 16 349–16 368, 1999.

Rinsland, C P., Goldman, A., Murcray, D G., Murcray, F J., and Devi, V M.: Tentative identification of the 780 cm−1 $\nu_4$ band Q branch of chlorine nitrate in high-resolution solar absorption spectra of the stratosphere, J. Geophys. Res., 90, 7931–7943, 1985.

Rinsland, C P., Zander, R., and Demoulin, P.: Ground-based infrared measurements of HNO3 total column abundances: long-term trend and variability, J. Geophys. Res., 96, 9379–9389, 1991.

Rinsland, C P., Gunson, M R., Abrams, M C., Zander, R., Mahieu, E., Goldman, A., Ko, M. K W., Rodriguez, J M., and Sze, N D.: Profiles of stratospheric chlorine nitrate (ClONO2) from atmospheric trace molecule spectroscopy/ATLAS 1 infrared solar occultation spectra, J. Geophys. Res., 99, 18 895–18 900, 1994.

Rinsland, C P., Gunson, M R., Salawitch, R J., Michelsen, H A., Zander, R., Newchurch, M J., Abbas, M M., Abrams, M C., Manney, G L., Chang, A Y., Irion, F W., Goldman, A., and Mahieu, E.: ATMOS/ATLAS-3 measurements of stratospheric chlorine and reactive nitrogen partitioning inside and outside the November 1994 Antarctic vortex, Geophys. Res. Lett., 23, 2365–2368, 1996.

Rinsland, C P., Jones, N B., Connor, B J., Logan, J A., Pougatchev, N S., Goldman, A., Murcray, F J., Stephen, T M., Pine, A S., Zander, R., Mahieu, E., P., and Demoulin: Northern and Southern Hemisphere ground-based infrared spectroscopic measurements of tropospheric carbon monoxide and ethane, J. Geophys. Res., 103, 28 197–28 217, 1998.

Roche, A., Kumer, J., Mergenthaler, J., Ely, G., Uplinger, W., Potter, J., James, T., and Sterritt, L.: The Cryogenic Limb Array Etalon Spectrometer (CLAES) on UARS: Experiment description and performance, J. Geophys. Res., 98, 10 763–10 775, 1993.

Roche, A E., Kumer, J B., Mergenthaler, J L., Nightingale, R W., Uplinger, W G., Ely, G A., and Potter, J F.: Observations of lower-stratospheric ClONO2, HNO3, and aerosol by the UARS CLAES experiment between January 1992 and April 1993, J. Atmos. Sci., 51, 2877–2902, 1994.

Rodgers, C D.: Inverse Methods for Atmospheric Sounding, Theory and Praxis, vol 2 of Series on Atmospheric, Oceanic and Planetary Physics, World Scientific, 2000.

Rodgers, C D. and Connor, B J.: Intercomparison of remote sounding instruments, J. Geophys. Res., 108, 4116, \doi10.1029/2002JD002299, 2003.

Roscoe, H K.: Review and revision of measurements of stratospheric N2O$_5$, J. Geophys. Res., 96, 10 879–10 884, \doi10.1029/90JD02388, 1991.

Rothman, L S., Jacquemart, D., Barbe, A., Benner, D C., Birk, M., Brown, L R., Carleer, M R., Chackerian, C., Chance, C., Coudert, L H., Dana, V., Devi, V M., Flaud, J M., Gamache, R R., Goldman, A., Hartmann, J M., Jucks, K W., Maki, A G., Mandin, J Y., Massie, S T., Orphal, J., Perrin, A., Rinsland, C P., Smith, M. A H., Tennyson, J., Tolchenov, R N., Toth, R A., Auwera, J V., Varanasi, P., and Wagner, G.: The HITRAN 2004 molecular spectroscopic database, J. Quant. Spectrosc. Radiat. Transfer, 96, 139–204, \doi10.1016/j.jqsrt.2004.10.008, 2005.

Schneider, M., Blumenstock, T., Chipperfield, M., Hase, F., Kouker, W., Reddmann, T., Ruhnke, R., Cuevas, E., and Fischer, H.: Subtropical trace gas profiles determined by ground-based FTIR spectroscopy at Izaña (28\degree N, 16\degree W): Five year record, error analysis, and comparison with 3D-CTMs, Atmos. Chem. Phys., 5, 153–167, 2005.

Salawitch, R J., Wofsy, S C., Wennberg, P O., Cohen, R C., Anderson, J G., Fahey, D W., Gao, R S., Keim, E R., Woodbridge, E L., Stimpfle, R M., Koplow, J P., Kohn, D W., Webster, C R., May, R D., Pfister, L., Gottlieb, E W., Michelsen, H A., Yue, G K., Prather, M J., Wilson, J C., Brock, C A., Jonsson, H H., Dye, J E., Baumgardner, D., Proffitt, M H., Loewenstein, M., Podolske, J R., Elkins, J W., Dutton, G S., Hintsa, E J., Dessler, A E., Weinstock, E M., Kelly, K K., Boering, K A., Daube, B C., Chan, K R., and Bowen, S W.: The diurnal variation of hydrogen, nitrogen, and chlorine radicals: Implications for the heterogeneous production of HNO3, Geophys. Res. Lett., 21, 2551–2554, 1994.

Santee, M L., Manney, G L., Froidevaux, L., Read, W G., and Water, J W.: Six years of UARS Microwave Limb Sounder HNO3 observations: Seasonal, interhemispheric, and interannual variations in the lower stratosphere, J. Geophys. Res., 104, 8225–8246, 1999.

Santee, M L., Manney, G L., Livesey, N J., and Read, W G.: Three-dimensional structure and evolution of stratospheric HNO3 based on UARS Microwave Limb Sounder measurements, J. Geophys. Res., 109, \doi101029/2004JD004578, 2004.

Santee, M L., Lambert, A., Read, W G., Livesey, N J., Cofield, R E., Cuddy, D T., Daffer, W H., Drouin, B J., Froidevaux, L., Fuller, R A., Jarnot, R F., Knosp, B W., Manney, G L., Perun, V S., Snyder, W V., Stek, P C., Thurstans, R P., Wagner, P A., Waters, J W., Muscari, G., de~Zafra, R L., Dibb, J E., Fahey, D W., Popp, P J., Marcy, T P., Jucks, K W., Toon, G C., Stachnik, R A., Bernath, P F., Boone, C D., Walker, K A., Urban, J., and Murtagh, D.: Validation of the Aura Microwave Limb Sounder HNO3 Measurements, J. Geophys. Res., 112, \doi10.1029/2007JD008721, 2007.

Senten, C., Mazière, M D., Dils, B., Hermans, C., Kruglanski, M., Neefs, E., Scolas, F., Vandaele, A C., Vanhaelewyn, G., Vigouroux, C., Carleer, M., Coheur, P F., Fally, S., Barret, B., Baray, J L., Delmas, R., Leveau, J., Metzger, J M., Mahieu, E., Boone, C., Walker, K A., Bernath, P F., and Strong, K.: Technical Note: New ground-based FTIR measurements at Ile de La Réunion: Observations, error analysis, and comparisons with independent data, Atmos. Chem. Phys., 8, 827–891, 2008.

Smith, S E., Dudhia, A., Morris, P E., Remedios, J J., Rodgers, C D., Taylor, F W., Kerridge, B J., Chipperfield, M P., Kumer, J B., Roche, A E., and Gunson, M R.: Dinitrogen pentoxide measurements from the Improved Stratospheric And Mesospheric Sounder: Validation of preliminary results, J. Geophys. Res., 101, 9897–9906, \doi10.1029/95JD02465, 1996.

Solomon, S.: Stratospheric Ozone Depletion: A review of concepts and history, Rev. Geophys., 37, 275–316, 1999.

Solomon, S., Portmann, R W., Garcia, R R., Thomason, L W., Poole, L R., and McCormick, M P.: The role of aerosol variations in anthropogenic ozone depletion at northern midlatitudes, J. Geophys. Res., 101, 6713–6727, 1996.

Stiller, G P., Tsidu, G M., von Clarmann, T., Glatthor, N., Höpfner, M., Kellmann, S., Linden, A., Ruhnke, R., and Fischer, H.: An enhanced HNO3 second maximum in the Antarctic mid-winter upper stratosphere 2003, J. Geophys. Res., 110, D20303, \doi10.1029/2005JD006011, 2005.

Strong, K., Wolff, M A., Kerzenmacher, T E., Walker, K A., Bernath, P F., Blumenstock., T., Boone, C., Catoire, V., Coffey, M., Mazière, M D., Demoulin, P., Duchatelet, P., Dupuy, E., Hannigan, J., Höpfner, M., Glatthor, N., Griffith, D. W T., Jin, J J., Jones, N., Jucks, K., Kuttippurath, J., Lambert, A., Mahieu, E., McConnell, J C., Mellqvist, J., Mikuteit, S., Murtagh, D P., Notholt, J., Piccolo, C., Robert, C., Schneider, M., Schrems, O., Semeniuk, K., Senten, C., Stiller, G P., Strandberg, A., Taylor, J R., Tétard, C., Toohey, M., Urban, J., Warneke, T., and Wood, S.: Validation of ACE-FTS N2O Measurements, Atmos. Chem. Phys. Discuss., 8, 3597–3663, 2008.

Taylor, F W., Rodgers, C D., Whitney, J G., Werrett, S T., Barnett, J., Peskett, G D., Venters, P., Ballard, J., Palmer, C. W P., Knight, R J., Morris, P., Nightingale, T., and Dudhia, A.: Remote sensing of atmospheric structure and composition by pressure modulator radiometry from space: The ISAMS experiment on UARS, J. Geophys. Res., 98, 10 799–10 814, 1993.

Taylor, F W., Ballard, J., Dudhia, A., Goss-Custard, M., Kerridge, B., Lambert, A., López-Valverde, M., Rodgers, C., and Remedios, J.: Stratospheric and mesospheric observations with ISAMS, Adv. Space Res., 14, 41–52, 1994.

100

Taylor, F W., Rodgers, C., Remedios, J., Grainger, R., Lambert, A., López-Valverde, M., Goss-Custard, M., and Reburn, J.: Global atmospheric chemistry from satellites: Results from UARS/ISAMS, Faraday Discuss., 100, 353–369, 1995.

101

Toohey, M. and Strong, K.: Estimating biases and error variances through the comparison of coincident satellite measurements, J. Geophys. Res., 112, D13306, \doi10.1029/2006JD008192, 2007.

102

Toohey, M., Quine, B M., Strong, K., Bernath, P F., Boone, C D., Jonsson, A I., McElroy, C T., Walker, K A., and Wunch, D.: Balloon-borne radiometer measurement of Northern Hemisphere mid-latitude stratospheric HNO3 profiles spanning 12 years, Atmos. Chem. Phys., 7, 6075–6084, 2007.

103

Toon, O B., Hamill, P., Turco, R P., and Pinto, J.: Condensation of HNO3 and HCl in the winter polar stratosphere, Geophys. Res. Lett., 13, 1284–1287, 1986.

104

Urban, J., Lautié, N., Flochmo\"en, E L., Jiménez, C., Eriksson, P., Dupuy, E., Amaroui, L E., Ekström, M., Frisk, U., Murtagh, D P., de~La~No\"e, J., Olberg, M., and Ricaud, P.: Odin/SMR Limb Observations of Stratospheric Trace Gases: Level~2 Processing of ClO, N2O, O3, and HNO3, J. Geophys. Res., 110, D14307, \doi10.1029/2004JD005741, 2005.

105

Urban, J., Murtagh, D P., Lautié, N., Barret, B., Dupuy, E., de No\"e, L., Eriksson, P., Frisk, U., Jones, A., E., F L., Olberg, M., Piccolo, C., Ricaud, P., and Rösevall, J.: Odin/SMR Limb Observations of Trace Gases in the Polar Lower Stratosphere during 2004-2005, in: Proc. ESA First Atmospheric Science Conference, edited by Lacoste, H., ESA-SP-628, European Space Agency, 2006.

106

Urban, J., Pommier, M., Murtagh, D P., Eriksson, P., and Ricaud, P.: Odin/SMR Limb Observations of Nitric Acid in the Stratosphere, in: Proc. ESA Envisat Symposium, edited by Lacoste, H. and Ouwehand, L., ESA-SP-636, European Space Agency, 2007.

107

Vigouroux, C., Mazière, M D., 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 N2O and HNO3 profiles before and after assimilation in BASCOE, Atmos. Chem. Phys., 7, 377–396, 2007.

108

von Clarmann, T.: Validation of remotely sensed profiles of atmospheric state variables: strategies and terminology, Atmos. Chem. Phys., 6, 4311–4320, 2006.

109

von Clarmann, T., Ceccherini, S., Doicu, A., Dudhia, A., Funke, B., Grabowski, U., Hilgers, S., Jay, V., Linden, A., López-Puertas, M., Mart\'in-Torres, F J., Payne, V., Reburn, J., Ridolfi, M., Schreier, F., Schwarz, G., Siddans, R., and Steck, T.: A blind test retrieval experiment for infrared limb emission spectrometry, J. Geophys. Res., 108, 4746, \doi10.1029/2003JD003835, 2003.

110

von König, M., Bremer, H., Eyring, V., Goede, A., Hetzheim, H., Kleipool, Q., Küllmann, H., and Künzi, K.: An airborne submm radiometer for the observation of stratospheric trace gases: Microwave Radiometry and Remote Sensing of the Earth's Surface and Atmosphere, Tech. rep., VSP, 409–415, 2000.

111

Wagner, G. and Birk, M.: New infrared spectroscopic database for chlorine nitrate, J. Quant. Spectrosc. Ra., 82, 443–460, 2003.

112

Waibel, A E., Peter, T., Carslaw, K S., Oelhaf, H., Wetzel, G., Crutzen, P J., P\"oschl, U., Tsias, A., Reimer, E., and Fischer, H.: Arctic ozone loss due to denitrification, Science, 283, 2064–2068, 1999.

113

Wang, D Y., Höpfner, M., Blom, C E., Ward, W E., Fischer, H., Blumenstock, T., Hase, F., Keim, C., Liu, G Y., Mikuteit, S., Oelhaf, H., Wetzel, G., Cortesi, U., Mencaraglia, F., Bianchini, G., Redaelli, G., Pirre, M., Catoire, V., Huret, N., Vigouroux, C., De Mazière, M., Mahieu, E., Demoulin, P., Wood, S., Smale, D., Jones, N., Nakajima, H., Sugita, T., Urban, J., Murtagh, D., Boone, D J., Bernath, P F., Walker, K A., Kuttippurath, J., Kleinböhl, A., Toon, G., and Piccolo, C.: Validation of MIPAS HNO3 operational data, Atmos. Chem. Phys., 7, 4905–4934, 2007a.

114

Wang, D Y., Höpfner, M., Mengistu Tsidu, G., Stiller, G P., von Clarmann, T., Fischer, H., Blumenstock, T., Glatthor, N., Grabowski, U., Hase, F., Kellmann, S., Linden, A., Milz, M., Oelhaf, H., Schneider, M., Steck, T., Wetzel, G., López-Puertas, M., Funke, B., Koukouli, M E., Nakajima, H., Sugita, T., Irie, H., Urban, J., Murtagh, D., Santee, M L., Toon, G., Gunson, M R., Irion, F W., Boone, C D., Walker, K., and Bernath, P F.: Validation of nitric acid retrieved by the IMK-IAA processor from MIPAS/ENVISAT measurements, Atmos. Chem. Phys., 7, 721–738, 2007b.

115

Waters, J W., Froidevaux, L., Harwood, R S., Jarnot, R F., Pickett, H M., Read, W G., Siegel, P H., Cofield, R E., Filipiak, M J., Flower, D A., Holden, J R., Lau, G K., Livesey, N J., Manney, G L., Pumphrey, H C., Santee, M L., Wu, D L., Cuddy, D T., Lay, R R., Loo, M S., Perun, V S., Schwartz, M J., Stek, P C., Thurstans, R P., Boyles, M A., Chandra, K M., Chavez, M C., Gun-Shing, C., Chudasama, B V., Dodge, R., Fuller, R A., Girard, M A., Jiang, J H., Yibo, J., Knosp, B W., LaBelle, R C., Lam, J C., Lee, K A., Miller, D., Oswald, J E., Patel, N C., Pukala, D M., Quintero, O., Scaff, D M., Snyder, W V., Tope, M C., Wagner, P A., and Walch, M J.: The Earth Observing System Microwave Limb Sounder (EOS MLS) on the Aura Satellite, IEEE Trans. Geosci. Remote Sens., 44, 1075–1092, \doi10.1109/TGRS.2006.873771, 2006.

116

Wetzel, G., Oelhaf, H., Friedl-Vallon, F., Kleinert, A., Lengel, A., Maucher, G., Nordmeyer, H., Ruhnke, R., Nakajima, H., Sasano, Y., Sugita, T., and Yokota, T.: Intercomparison and validation of ILAS-II version 1.4 target parameters with MIPAS-B measurements, J. Geophys. Res., 111, D11S06, \doi10.1029/2005JD006287, 2006.

117

Yokota, T., Nakajima, H., Sugita, T., Tsubaki, H., Itou, Y., Kaji, M., Suzuki, M., Kanzawa, H., Park, J H., and Sasano, Y.: Improved Limb Atmospheric Spectrometer (ILAS) data retrieval algorithm for Version 5.20 gas profile products, J. Geophys. Res., 107, 8216, \doi10.1029/2001JD000628, 2002.

118

Zander, R. and Demoulin, P.: Spectroscopic evidence for the presence of the $\nu_4$-Q branch of chlorine nitrate (ClONO2) in ground-based infrared solar spectra, J. Atmos. Chem., 6, 191–200, 1988.

119

Zander, R., Rinsland, C P., Farmer, C B., Brown, L R., and Norton, R H.: Observation of several chlorine nitrate (ClONO2) bands in stratospheric infrared spectra, Geophys. Res. Lett., 13, 757–760, 1986.

120

Zander, R., Mahieu, E., Gunson, M R., Abrams, M C., Chang, A Y., Abbas, M., Aellig, C., Engel, A., Goldman, A., Irion, F W., Kampfer, N., Michelsen, H A., Newchurch, M J., Rinsland, C P., Salawitch, R J., Stiller, G P., and Toon, G C.: The 1994 northern midlatitude budget of stratospheric chlorine derived from ATMOS/ATLAS-3 observations, Geophys. Res. Lett., 23, 2357–2360, 1996.

121

Zander, R., Mahieu, E., Demoulin, P., Duchatelet, P., Roland, G., Servais, C., Mazière, M D., Reimann, S., P., C., and Rinsland: Our changing atmosphere: evidence based on long-term infrared solar observations at the Jungfraujoch since 1950, Sci. Tot. Environ., 391, 184–195, 2007.