References

ACP

Atmospheric Chemistry and Physics

ACP

1680-7324

Copernicus GmbH

Göttingen, Germany

10.5194/acp-9-5299-2009

Evaluation of balloon and satellite water vapour measurements in the Southern tropical and subtropical UTLS during the HIBISCUS campaign

Montoux

¹ ² Hauchecorne

¹ Pommereau

J.-P.

¹ Lefèvre

¹ Durry

¹ ³ Jones

R. L.

⁴ Rozanov

⁵ Dhomse

⁵ ⁶ Burrows

J. P.

⁵ Morel

² Bencherif

Laboratoire atmosphères, milieux, observations spatiales, Université Paris VI, CNRS, Verrières-le-Buisson, France

Laboratoire de l'Atmosphère et des Cyclones, Université de la Réunion, CNRS, St-Denis de la Réunion, France

Groupe de Spectroscopie moléculaire et Atmosphérique, Université de Reims Champagne-Ardenne, CNRS, Reims, France

Center for Atmospheric Science, University Chemical Laboratory, University of Cambridge, Cambridge, UK

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

now at: the School of Earth and Environment, University of Leeds, UK

29 07 2009

9 14 5299 5319

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/9/5299/2009/acp-9-5299-2009.html

The full text article is available as a PDF file from http://www.atmos-chem-phys.net/9/5299/2009/acp-9-5299-2009.pdf

Balloon water vapour in situ and remote measurements in the tropical upper troposphere and lower stratosphere (UTLS) obtained during the HIBISCUS campaign around 20° S in Brazil in February–March 2004 using a tunable diode laser (μSDLA), a surface acoustic wave (SAW) and a Vis-NIR solar occultation spectrometer (SAOZ) on a long duration balloon, have been used for evaluating the performances of satellite borne remote water vapour instruments available at the same latitude and measurement period. In the stratosphere, HALOE displays the best precision (2.5%), followed by SAGE II (7%), MIPAS (10%), SAOZ (20–25%) and SCIAMACHY (35%), all of which show approximately constant H2O mixing ratios between 20–25 km. Compared to HALOE of ±10% accuracy between 0.1–100 hPa, SAGE II and SAOZ show insignificant biases, MIPAS is wetter by 10% and SCIAMACHY dryer by 20%. The currently available GOMOS profiles of 25% precision show a positive vertical gradient in error for identified reasons. Compared to these, the water vapour of the Reprobus Chemistry Transport Model, forced at pressures higher than 95 hPa by the ECMWF analyses, is dryer by about 1 ppmv (20%). In the lower stratosphere between 16–20 km, most notable features are the steep degradation of MIPAS precision below 18 km, and the appearance of biases between instruments far larger than their quoted total uncertainty. HALOE and SAGE II (after spectral adjustment for reducing the bias with HALOE at northern mid-latitudes) both show decreases of water vapour with a minimum at the tropopause not seen by other instruments or the model, possibly attributable to an increasing error in the HALOE altitude registration. Between 16–18 km where the water vapour concentration shows little horizontal variability, and where the μSDLA balloon measurements are not perturbed by outgassing, the average mixing ratios reported by the remote sensing instruments are substantially lower than the 4–5 ppmv observed by the μSDLA. Differences between μSDLA and HALOE and SAGE II (of the order of −2 ppmv), SCIAMACHY, MIPAS and GOMOS (−1 ppmv) and SAOZ (−0.5 ppmv), exceed the 10% uncertainty of μSDLA, implying larger systematic errors than estimated for the various instruments. In the upper troposphere, where the water vapour concentration is highly variable, AIRS v5 appears to be the most consistent within its 25% uncertainty with balloon in-situ measurements as well as ECMWF. Most of the remote measurements show less reliability in the upper troposphere, losing sensitivity possibly because of absorption line saturation in their spectral ranges (HALOE, SAGE II and SCIAMACHY), instrument noise exceeding 100% (MIPAS) or imperfect refraction correction (GOMOS). An exception is the SAOZ-balloon, employing smaller H2O absorption bands in the troposphere.

References 1

Andersson, E., Hólm, E., Bauer, P., Beljaars, A., Kelly, G. A., McNally, A. P., Simmons, A. J., Thépaut, J.-N., and Tompkins, A. M.: Analysis and forecast impact of the main humidity observing systems, Q. J. Roy. Meteor. Soc., 133, 1473–1485, 2007.

Aumann, H. H., Chahine, M. T., Gautier, C., Goldberg, M. D., Kalnay, E., McMillin, L. M., Revercomb, H., Rosenkranz, P. W., Smith, W. L., Staelin, D. H., Strow, L. L., and Susskind, J.: AIRS/AMSU/HSB on the Aqua mission: Design, science objectives, data products, and processing systems, IEEE T. Geosci. Remote Sens., 41, 253–264, 2003.

Bertaux, J. L., Dalaudier, F., Hauchecorne, A., Chipperfield, M., Fussen, D., Kyrölä, E., Leppelmeier, E., and Roscoe, H.: Envisat: GOMOS-An instrument for global atmosphere ozone monitoring, edited by: Harris R. A., ESA SP-1244, 109 pp., May 2001.

Borchi, F., Pommereau, J.-P., Garnier, A., and Pinharanda, M.: Evaluation of SHADOZ sondes, HALOE and SAGE II ozone profiles at the tropics from SAOZ UV-Vis remote measurements onboard long duration balloons, Atmos. Chem. Phys., 5, 1381–1397, 2005.

Borchi, F., and Pommereau, J.-P.: Evaluation of ozonesondes, HALOE, SAGE II and III, Odin-OSIRIS and -SMR, and ENVISAT-GOMOS, -SCIAMACHY and -MIPAS ozone profiles in the tropics from SAOZ long duration balloon measurements in 2003 and 2004, Atmos. Chem. Phys., 7, 2671–2690, 2007.

Bovensmann, H., Burrows, J. P., Buchwitz, M., Frerick, J., No\"el, S., Rozanov, V. V., Chance, K. V., and Goede, A. H. P.: SCIAMACHY – Mission Objectives and Measurement Modes, J. Atmos. Sci., 56, 127–150, 1999.

Buchwitz, M., Rozanov, V. V., and Burrows, J. P.: A correlated-k distribution scheme for overlapping gases suitable for retrieval of atmospheric constituents from moderate resolution radiance measurements in the visible/near-infrared spectral region. J. Geophys. Res., 105, 15247–15261, 2000.

Burrows, J. P., Hölzle E., Goede, A. P. H., Visser, H., and Fricke W.: SCIAMACHY – Scanning Imaging Absorption Spectrometer for Atmospheric Chartography, Acta Astron., 35, 7, 445–451, 1995.

Chiou, E.-W., Thomason, L. W., Burton, S. P., and Michelsen, H. A.: Assessment of the SAGE II version 6.2 water vapor data set through intercomparison with ATMOS/ATLAS-3 measurements, Geophys. Res. Lett., 31, L14101, doi:10.1029/2004GL020071, 2004.

Dhomse, S., Weber, M., and Burrows, J.: The relationship between tropospheric wave forcing and tropical lower stratospheric water vapour, Atmos. Chem. Phys., 8, 471–480, 2008.

Divakarla, M. G., Barnet, C. D., Goldberg, M. D., McMillin, L. M., Maddy, E., Wolf, W., Zhou, L., and Liu, X.: Validation of Atmospheric Infrared Sounder temperature and water vapour retrievals with matched radiosonde measurements and forecasts, J. Geophys. Res., 11, D09S15, doi:10.1029/2005JD006116, 2006.

Durry, G. and Megie, G.: Atmospheric CH4 and H2O monitoring with near-infrared InGaAs laser diodes by the SDLA, a balloonborne spectrometer for tropospheric and stratospheric in-situ measurements,~Appl. Opt., 38, 7342–7354, 1999.

Durry, G. and Megie, G.: In-situ measurements of H2O from a stratospheric balloon by diode laser direct-differential absorption spectroscopy at 1.39 μm, Appl. Opt., 39, 5601–5608, 2000.

Durry, G., Zeninari, V., Parvitte, B., Le Barbu, T., Lefevre, F., Ovarlez, J., and Gamache, R. R.: Pressure-broadening coefficients and line strengths of H2O near 1.39 μm: application to the in-situ sensing of the middle atmosphere with balloonborne diode lasers, J. Quant. Spectrom. Rad. T., 94, 387–403, 2005.

Durry, G., Huret, N., Hauchecorne, A., Marecal, V., Pommereau, J.-P., Jones, R. L., Held, G., Larsen, N., and Renard, J.-B.: Isentropic advection and convective lifting of water vapour in the UT LS as observed over Brazil (22° S) in February 2004 by the in-situ high-resolution measurements of H2O, CH4, O3 and temperature, Atmos. Chem. Phys. Discuss, 6, 12469–12501, 2006.

ESA, ENVISAT-1 Mission and System Summary, issue 2, 85 p., 1 March 1998. online available at: http://envisat.esa.int/support-docs/pdf/mis_sys.pdf

Fischer, H., Blom, C., Oelhaf, H., Carli, B., Carlotti, M., Delbouille, L., Ehhallt, D., Flaud, J.-M., Isaksen, I., Lopez-Puertas, M., McElroy, C. T., and Zander, R.: ENVISAT-MIPAS - An instrument for atmospheric chemistry and climate research, ESA Pub. SP-1229, 2000.

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., Lopez-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.

Forster, P. M. de F. and Shine, K. P.: Stratospheric water vapour changes as a possible contributor to observed stratospheric cooling, Geophys. Res. Lett., 26, 3309–3312, 1999.

Fueglistaler, S., Bonazzola, M., Haynes, P. H., and Peter, T.: Stratospheric water vapor predicted from the Lagrangian temperature history of air entering the stratosphere in the tropics, J. Geophys. Res., 110, D08107, doi:10.1029/2004JD005516, 2005.

Fueglistaler, S. and Haynes, P. H.: Control of interannual and longer-term variability of stratospheric water vapor, J. Geophys. Res., 110, D24108, doi:10.1029/2005JD006019, 2005.

Geller, M. A., Zhou, X., and Zhang, M : Simulations of the interannual variability of stratospheric water vapour, J. Atmos. Sci., 59, 1076–1085, 2002.

Gettelman, A., Weinstock, E. M., Fetzer, E. J., Irion, F. W., Eldering, A., Richard, E. C., Rosenlof, K. H., Thompson, T. L., Pittman, J. V., Webster, C. R., and Herman, R. L.: Validation of Aqua satellite data in the upper troposphere and lower stratosphere with in-situ aircraft instruments, Geophys. Res. Lett., 31, L22107, doi:10.1029/2004GL020730, 2004.

Grooß, J.-U. and Russell III, J. M.: Technical note: A stratospheric climatology for O3, H2O, CH4, NOx, HCl and HF derived from HALOE measurements, Atmos. Chem. Phys., 5, 2797–2807, 2005.

Hagan, D. E., Webster C. R., Farmer C. B., May, R. D., Herman, R. L., Weinstock, E. M., Christensen, L. E., Lait, L. R., and Newman, P. A.: Validating AIRS upper atmosphere water vapor retrievals using aircraft and balloon in-situ measurements, Geophys. Res. Lett., 31, L21103, doi:10.1029/2004GL020302, 2004.

Hansford, G. M., Freshwater, R. A., Eden, L., Turnbull, K. F. V., Hadaway, D. E., Ostanin, V. P., and Jones, R. L.: Lightweight dew-/frost-point hygrometer based on a surface-acoustic-wave sensor for balloon-borne atmospheric water vapor profile sounding, Rev. Sci. Instrum., 77, 014502, doi:10.1063/1.2140275, 2006.

Harries, J. E., Russell III, J. M., Tuck, A. F., Gordley, L. L., Purcell, P., Stone, K., Bevilacqua, R. M., Gunson, M., Nedoluha, G., and Traub, W. A.: Validation of measurements of water vapor from the Halogen Occultation Experiment (HALOE), J. Geophys. Res., 101, 10205–10216, 1996.

Hervig, M. E. and McHugh, M. J.: Cirrus detection using HALOE measurements, Geophys. Res. Lett., 26, 719–722, 1999.

Hocke, K., Kämpfer, N., Ruffieux, D., Froidevaux, L., Parrish, A., Boyd, I., Von Clarmann, T., Steck, T., Timofeyev, Y. M., Polyakov, A. V., and Kyrölä, E.: Comparison and synergy of stratospheric ozone measurements by satellite limb sounders and the ground-based microwave radiometer SOMORA, Atmos. Chem. Phys., 7, 4117–4131, 2007.

Jensen, E. J., Kinne, S., and Toon, O. B.: Tropical cirrus clouds radiative forcing: Sensitivity studies, Geophys. Res. Lett., 21, 2023–2026, 1994.

Kelly, K. K., Profitt, M. H., Chan, K. R., Loewenstein, M., Podolske, J. R., Strahan, E., Wilson, J. C., and Kley., D.: Water vapor and cloud water measurements over Darwin during the STEP 1987 tropical mission, J. Geophys. Res., 98, 8713–8723, 1993.

Kiefer, M., Von Clarmann, T., Grabowski, U., De Laurentis, M., Mantovani, R., Milz, M. and Ridolfi, M.: Characterization of MIPAS elevation pointing, Atmos. Chem. Phys., 7, 1615–1628, 2007.

Kiehl, J. T. and Trenberth, K. E.: Earth's annual global mean energy budget, B. Am. Meteor. Soc., 78, 197–208, 1997.

Kley, D., Russell III, J. M., and Phillips, C.: SPARC (Stratospheric Processes And their Role in Climate) Assessment of Upper Tropospheric and Stratospheric Water Vapour, WCRP-113, WMO/TD No. 1043, SPARC Report No.2, 2000.

Kneizys, F. X., Shettle, E. P., Abreu, L. W., Chetwynd, J. H., Anderson, G. P., Gallery, W. O., Selby, J. E. A., and Clough, S. A.: Users Guide to LOWTRAN 7. Technical report, Air Force Geophysics Laboratory AFGL, 1986.

Kyrölä, E., Tamminen, J., Leppelmeier, G. W., Sofieva, V., Hassinen, S., Seppälä, A., Verronen, P. T., Bertaux, J.-L., Hauchecorne, A., Dalaudier, F., Fussen, D., Vanhellemont, F., Fanton d'Andon, O., Barrot, G., Mangin, A., Theodore,B., Guirlet, M., Koopman, R., Saavedra de Miguel L., Snoeij, P., Fehr, T., Meijer, Y., and Fraisse, R.: Nighttime ozone profiles in the stratosphere and mesosphere by the Global Ozone Monitoring by Occultation of Stars on Envisat, J. Geophys. Res., 111, D24306, doi:10.1029/2006JD007193, 2006.

Lefèvre, F., Brasseur, G. P., Folkins, I., Smith, A. K., and Simon, P.: Chemistry of the 1991–1992 stratospheric winter: Three-dimensional model simulations, J. Geophys. Res., 99, 8183–8195, 1994.

Lelieveld, J., Brühl, C., Jöckel, P., Steil, B., Crutzen, P. J., Fischer, H., Giorgetta, M. A. Hoor, P., Lawrence, M. G., Sausen, R., and Tost, H.: Stratospheric dryness: model simulations and satellite observations, Atmos. Chem. Phys., 7, 1313–1332, 2007.

Luo, Z., Kley, D., Johnson, R. H., and Smit, H.: Ten years of measurements of tropical upper-tropospheric water vapor by MOZAIC. Part II: assessing the ECMWF humidity analysis, J. Climate, 21, 1449–1466, doi:10.1175/2007JCLI1887.1, 2008.

Marécal, V., Durry, G., Longo, V., Freitas, S., Rivière, E. D., and Pirre, M.: Mesoscale modelling of water vapour in the tropical UTLS: two case studies from the HIBISCUS campaign, Atmos. Chem. Phys., 7, 1471–1489, 2007.

Mauldin III, L. E., Zaun, N. H, McCormick, M. P, Guy, J. H., and Vaughan, W. P.: Stratospheric Aerosol and Gas Experiment II Instrument: A Functional Description, Opt. Eng., 24, 307–312, 1985.

Monge-Sanz, B. M., Chipperfield, M. P., Simmons, A. J., and Uppala, S. M.: Mean age of air and transport in a CTM: comparison of different ECMWF analyses. Geophys. Res. Lett., 34, L04801, doi:10.1029/2006GL028515, 2007.

Nielsen, J. K., Larsen, N., Cairon, F., Donfrancesco, Di., G., Rosen, J. M., Durry, G., Hels, G., and Pommereau, J.-P.: Solid particles in the tropical lower stratosphere, Atmos. Chem. Phys., 7, 685–695, 2007.

Nuret, M., Lafore, J.-P., Bock, O., Guichard, F., Agusti-Panareda, A., N'Gamini, J.-B., and Redelsperger, J.-L.: Correction of humidity bias for Vaisala RS80-A sondes during the AMMA 2006 observing period, J. Atm. Ocean. Tech., 25, 2152–2158, doi:10.1175/2008JTECHA1103.1, 2008.

Oelhaf, H., Fix, A., Schiller, C., Chance, K., Gurlit, W., Ovarlez, J., Renard, J.-B., Rohs, S., Wetzel, G., Von Clarmann, T., Milz, M., Wang, D.-Y., Remedios, J. J., and Waterfall, A. M.: Validation of MIPAS-ENVISAT version 4.61 operational data with balloon and aircraft measurements: H20, ESA SP-562, August 2004.

Oltmans, S. J. and Hofmann D. J.: Increase in lower-stratospheric water vapor at a mid-latitude Northern Hemisphere site from 1981 to 1994, Nature, 374, 146–149, 1995.

Oltmans, S. J., Vömel, H., Hofmann, D. J., Rosenlof, K. H., and Kley, D.: The increase in stratospheric water vapor from balloon-borne, frostpoint hygrometer measurements at Washington, DC and Boulder, Colorado, Geophys. Res. Lett., 27, 3453–3456, 2000.

Osterman, G. B., Salawitch, R. J., Sen, B., Toon, G. C., Stachnik, R. A., Pickett, H. M., Margitan, J. J., Blavier, J.-F., and Peterson, D. B.: Balloon-borne measurements of stratospheric radicals and their precursors: Implications for the production and loss of ozone, Geophys. Res. Lett., 24, 1107–1110, 1997.

Ovarlez, J. and Van Velthoven, P.: Comparison of Water Vapor Measurements with Data Retrieved from ECMWF Analyses during the POLINAT Experiment, J. Appl. Meteorol., 36, 1329–1335, 1997.

Parkinson, C. L.: Aqua: An Earth-Observing Satellite Mission to Examine Water and Other Climate Variables, IEEE Trans. Geosci. Remote Sens., 41, 173–183, 2003.

Piccolo, C. and Dudhia, A.: Precision validation of MIPAS-Envisat products, Atmos. Chem. Phys., 7, 1915–1923, 2007.

Pommereau, J. P. and Piquard, J.: Ozone and nitrogen dioxide vertical distributions by uv-visible solar occultation from balloons, Geophys. Res. Lett., 21, 1227–1230, 1994.

Pommereau, J.-P. and the Hibiscus team: An overview of the HIBISCUS campaign, Atmos. Chem. Phys. Discuss., 7, 2389–2475, 2007.

Randel, W. J., Wu, F., Vömel, H., Nedoluha, G. E., and Forster, P.: Decreases in stratospheric water vapour after 2001: Links to changes in the tropical tropopause and the Brewer-Dobson circulation, J. Geophys. Res., 111, D12312, doi:10.1029/2005JD006744, 2006.

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. J., Ridolfi, M., and Spang, R.: MIPAS level 2 operational analysis, Atmos. Chem. Phys., 6, 5605–5630, 2006.

Read, W. G., Lambert, A., Bacmeister, J., Cofield, R. E., Christensen, L. E., Cuddy, D. T., Daffer, W. H., Drouin, B. J., Fetzer, E., Froidevaux, L., Fuller, R., Herman, R., Jarnot. R. F., Jiang, J. H., Jiang, Y. B., Kelly, K., Knosp, B. W., Kovalenko, L. J., Livesey, N. J., Liu, H.-C., Manney, G. L., Pickett, H. M., Pumphrey, H. C., Rosenlof, K. H., Sabounchi, X., Santee, M. L., Schwartz, M. J., Snyder, W. V. Stek, P. C., Su, H., Takacs, L. L., Thurstans, R. P., Vömel, H., Wagner, P. A., Waters, J. W., Webster, C. R., Weinstock, E. M., and Wu, D. L. : Aura Microwave Limb Sounder upper tropospheric and lower stratospheric H2O and relative humidity with respect to ice validation, J. Geophys. Res., 112, D24S35, doi:10.1029/2007JD008752, 2007.

Remedios, J. J., Leigh, R. J., Waterfall, A. M., Moore, D. P., Sembhi, H., Parkes, I., J. Greenhough, Chipperfield, M. P., and Hauglustaine, D.: MIPAS reference atmospheres and comparisons to V4.61/V4.62 MIPAS level 2 geophysical data sets, Atmos. Chem. Phys. Discuss., 7, 9973–10017, 2007.

Rodgers, C. D.: Inverse methods for atmospheric sounding: Theory and practice, Series on Atmospheric, Oceanic and planetary Physics, World Scientific Publishing Co. Ltd., vol. 2, 240 pp., 2000.

Rosenkranz, P. W.: Retrieval of temperature and moistures profiles from AMSU-A AMSU-B measurements, IEEE T. Geosci. Remote Sens., 39, 2429–2435, 2001.

Rosenlof, K. H., and Reid, G.: Trends in the temperature and water vapour content of the tropical lower stratosphere: sea surface connection, J. Geophys. Res. 113, D06107, doi:10.1029/2007JD009109, 2008.

Rothman, L.S., Jaquemart, D., Barbe, A., Benner, D. C., Birk, M., Brown, L. R., Carleer, M. R., Chackerian, C., Chance, K., 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., Vander Auwera, J., Varanasi, P., and Wagner, G.: The HITRAN 2004 molecular spectroscopic database, J. Quant. Spectrosc. Radiat. T., 96, 139-204, 2005.

Rozanov, A., Rozanov, V., and Burrows, J. P.: A numerical radiative transfer model for a spherical planetary atmosphere: Combined differential–integral approach involving the Picard iterative approximation, J. Quant. Spectrosc. Radiat. Transfer, 69, 491–512, 2001.

Rozanov, A., Rozanov, V., Buchwitz, M., Kokhanovsky, A., and Burrows, J. P.: SCIATRAN 2.0 - A new radiative transfer model for geophysical applications in the 175–2400 nm spectral region, Adv. Space Res., 36, 1015–1019, doi:10.1016/j.asr.2005.03.012, 2005a.

Rozanov, A., Bovensmann, H., Bracher, A., Hrechanyy, S., Rozanov, V., Sinnhuber, M., Stroh, F., and Burrows, J.: NO2 and BrO vertical profiles retrieval from SCIAMACHY limb measurements: Sensitivity studies, Adv. Space Res., 36, 846–854, doi:10.1016/j.asr.2005.03.013, 2005b.

Rozanov, A., Eichmann, K.-U., Von Savigny, C., Bovensmann, H., Burrows, J. P., Von Bargen, A., Doicu, A., Hilgers, S., Godin-Beekmann, S., Leblanc, T., and McDermid, I. S., Comparison of the inversion algorithms applied to the ozone vertical profile retrieval from SCIAMACHY limb measurements, Atmos. Chem. Phys., 7, 4763–4779, 2007.

Rozanov, A.: SCIATRAN: Radiative transfer model and retrieval software package, http://www.iup.physik.uni-bremen.de/sciatran, 2008.

Russel III, J. M., Gordley, L. L., Park, J. H., Drayson, S. R., Hesketh, W. D., Cicerone, R. J., Tuck, A. F., Frederick, J. E., Harries, J. E., and Crutzen, P. J.: The HALogen Occultation Experiment, J. Geophys. Res., 98, 10777–10797, 1993.

Scherer, M., Vömel, H., Fueglistaler, S., Oltmans, S. J., and Staehelin, J.: Trends and variability of midlatitude stratospheric water vapour deduced from re-evaluted Boulder balloon series and HALOE, Atmos. Chem. Phys. Discuss., 7, 14511–14542, 2007.

Sherwood, C. S. and Dessler., A.: On the control of stratospheric humidity, Geophys. Res. Lett., 16, 2513–2516, 2000.

Susskind, J., Barnet, C. D., and Blaisdell, J. M.: Retrieval of Atmospheric and Surface Parameters from AIRS/AMSU/HSB Data in the Presence of Clouds, IEEE T. Geosci. Remote Sens., 41, 390–409, 2003.

Taha, G., Thomason, L. W., and Burton, S. P.: Comparison of Stratospheric Aerosol and Gas Experiment (SAGE) II version 6.2 water vapor with balloon-borne and space-based instruments, J. Geophys. Res., 109, D18313, doi:10.1029/2004JD004859, 2004.

Tobin, D. C., Revercomb, H. E., Knuteson, R. O., Lesht, B. M., Strow, L. L., Hannon, S. E., Feltz, W. F., Moy, L. A., Fetzer, E. J., and Cress, T. S. : Atmospheric Radiation Measurement site atmospheric state best estimates for Atmospheric Infrared Sounder temperature and water vapour retrieval validation, J. Geophys. Res., 111, D09S14, doi:10.1029/2005JD006103, 2006.

Thomason, L. W., Burton, S. P., Iyer, N., Zawodny, J. M., and Anderson, J.: A revised water vapor product for the Stratospheric Aerosol and Gas Experiment (SAGE) II version 6.2 data set, J. Geophys. Res., 109, D06312, doi:10.1029/2003JD004465, 2004.

Wagner, W., Saul, A., and Pruß, A.: International Equations for the Pressure Along the Melting and Along the Sublimation Curve of Ordinary Water Substance, J. Phys. Chem. Ref. Data, 23, 515-527, 1994.

Von Savigny, C., Rozanov, A., Bovensmann, H., Eichmann, K.-U., Noel, S., Rozanov, V. V., Sinnhuber, B.-M.,Weber, M., Burrows, J. P., and Kaiser, J. W.: The ozone hole break-up in September 2002 as seen by SCIAMACHY on ENVISAT, J. Atm. Sci., 62, 721–734, doi:10.1175/JAS-3328.1, 2005.

Wennberg, P.O., Cohen, R. C., Stimpfle, R. M., Koplow, J. P., Anderson, J. G., Salawitch, R. J., Fahey, D. W., Woodbridge, E. L., Keim, E. R., Gao, R. S., Webster, C. R., May, R. D., Toohey, D. W., Avallone, L. M., Proffitt, M. H., Loewenstein, M., Podolske, J. R., Chan, K. R., and Wofsy, S. C.: Removal of stratospheric O3 by radicals: In-situ measurements of OH, HO2, NO, NO2, ClO and BrO, Science, 266, 398–404, 1994.