References

ACP

Atmospheric Chemistry and Physics

ACP

1680-7324

Copernicus GmbH

Göttingen, Germany

10.5194/acp-12-2899-2012

A-train CALIOP and MLS observations of early winter Antarctic polar stratospheric clouds and nitric acid in 2008

Lambert

¹ Santee

M. L.

¹ Wu

D. L.

¹ ² Chae

J. H.

¹ ³

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

now at: NASA Goddard Space Flight Center, Greenbelt, Maryland, USA

now at: Department of Geological Sciences, University of Texas at Austin, Austin, Texas, USA

23 03 2012

12 6 2899 2931

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/12/2899/2012/acp-12-2899-2012.html

The full text article is available as a PDF file from http://www.atmos-chem-phys.net/12/2899/2012/acp-12-2899-2012.pdf

A-train Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP) and Microwave Limb Sounder (MLS) observations are used to investigate the development of polar stratospheric clouds (PSCs) and the gas-phase nitric acid distribution in the early 2008 Antarctic winter. Observational evidence of gravity-wave activity is provided by Atmospheric Infrared Sounder (AIRS) radiances and infrared spectroscopic detection of nitric acid trihydrate (NAT) in PSCs is obtained from the Michelson Interferometer for Passive Atmospheric Sounding (MIPAS). Goddard Earth Observing System Data Assimilation System (GEOS-5 DAS) analyses are used to derive Lagrangian trajectories and to determine temperature-time histories of air parcels. We use CALIOP backscatter and depolarization measurements to classify PSCs and the MLS measurements to determine the corresponding gas-phase HNO3 as a function of temperature. For liquid PSCs the uptake of HNO3 follows the theoretical equilibrium curve for supercooled ternary solutions (STS), but at temperatures about 1 K lower as determined from GEOS-5. In the presence of solid phase PSCs, above the ice frost-point, the HNO3 depletion occurs over a wider range of temperatures (+2 to −7 K) distributed about the NAT equilibrium curve. Rapid gas-phase HNO3 depletion is first seen by MLS from from 23–25 May 2008, consisting of a decrease in the volume mixing ratio from 14 ppbv (parts per billion by volume) to 7 ppbv on the 46–32 hPa (hectopascal) pressure levels and accompanied by a 2–3 ppbv increase by renitrification at the 68 hPa pressure level. The observed region of depleted HNO3 is substantially smaller than the region bounded by the NAT existence temperature threshold. Temperature-time histories of air parcels demonstrate that the depletion is more clearly correlated with prior exposure to temperatures a few kelvin above the frost-point. From the combined data we infer the presence of large-size NAT particles with effective radii >5–7 μm and low NAT number densities <1 × 10−3 cm−3. This denitrification event is observed close to the pole in the Antarctic vortex before synoptic temperatures first fall below the ice frost point and before the widespread occurrence of large-scale NAT PSCs. An episode of mountain wave activity detected by AIRS on 28 May 2008 led to wave-ice formation in the rapid cooling phases over the Antarctic Peninsula and Ellsworth Mountains, seeding an outbreak of NAT PSCs that were detected by CALIOP and MIPAS. The NAT clouds formed at altitudes of 18–26 km in a polar freezing belt and appear to be composed of relatively small particles with estimated effective radii of around 1 μm and high NAT number densities >0.2 cm−3. This NAT outbreak is similar to an event previously reported from MIPAS observations in mid-June 2003.

References 1

Adhikari,~L., Wang,~Z., and Liu,~D.: Microphysical properties of Antarctic polar stratospheric clouds and their dependence on tropospheric cloud systems,~J. Geophys. Res., 115, D00H18, http://dx.doi.org/10.1029/2009JD012125doi:10.1029/2009JD012125, 2010.

Adriani,~A., Massoli,~P., Di~Donfrancesco,~G., Cairo,~F., Moriconi,~M L., and Snels,~M.: Climatology of polar stratospheric clouds based on lidar observations from 1993 to 2001 over McMurdo Station, Antarctica,~J. Geophys. Res., 109, D24211, http://dx.doi.org/10.1029/2004JD004800doi:10.1029/2004JD004800, 2004.

Aguzzi,~A. and Rossi,~M J.: The kinetics of the uptake of \chemHNO_3 on ice, solid \chemH_2SO_4-\chemH_2O and solid ternary solutions of \chemH_2SO_4-\chemHNO_3-\chemH_2O in the temperature range 180–211 K, Phys. Chem. Chem. Phys., 3, 3707–3716, http://dx.doi.org/10.1039/b100546odoi:10.1039/b100546o, 2001.

Alexander,~S P., Klekociuk,~A R., Pitts,~M C., McDonald,~A J., and Arevalo-Torres,~A.: The effect of orographic gravity waves on Antarctic polar stratospheric cloud occurrence and composition,~J. Geophys. Res., 116, D06109, http://dx.doi.org/10.1029/2010JD015184doi:10.1029/2010JD015184, 2011.

Arnold,~F., Bürger,~V., Gollinger,~K., Roncossek,~M., Schneider,~J., and Spreng,~S.: Observations of nitric acid perturbations in the winter Arctic stratosphere: evidence for PSC sedimentation,~J. Atmos. Chem., 30, 49–59, 1998.

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.

Biele,~J., Tsias,~A., Luo,~B P., Carslaw,~K S., Neuber,~R., Beyerle,~G., and Peter,~T.: Nonequilibrium coexistence of solid and liquid particles in Arctic stratospheric clouds,~J. Geophys. Res., 106, 22991–23007, 2001.

Biermann,~U M., Presper,~T., Mößinger,~J., Crutzen,~P J., and Peter,~T.: The unsuitability of meteoritic and other nuclei for polar stratospheric cloud freezing, Geophys. Res. Lett., 23, 1693–1696, 1996.

Biermann,~U M., Crowley,~J N., Huthwelker,~T., Moortgat,~G K., Crutzen,~P J., and Peter,~T.: FTIR studies on lifetime prolongation of stratospheric ice particles due to NAT coating, Geophys. Res. Lett., 25, 3939–3942, 1998.

Brooks, S D., Toon, O B., Tolbert, M A., Baumgardner, D., Gandrud, B., Browell, E V., Flentje, H., and Wilson, J C.: Polar stratospheric clouds during SOLVE/THESEO: Comparison of lidar observations with in situ measurements, J. Geophys. Res., 109, D02212, http://dx.doi.org/10.1029/2003JD003463doi:10.1029/2003JD003463, 2004.

Browell,~E V., Butler,~C F., Ismail,~S., Robinette,~P A., Carter,~A F., Higdon,~N S., Toon,~O B., Schoeberl,~M R., and Tuck,~A F.: Airborne lidar observations in the wintertime Arctic stratosphere: polar stratospheric clouds, Geophys. Res. Lett., 17, 385–388, 1990.

Cariolle,~D., Muller,~S., Cayla,~F., and McCormick,~M P.: Mountain waves, polar stratospheric clouds, and the ozone depletion over Antarctica,~J. Geophys. Res., 94, 11233–11240, 1989.

Carlsaw,~K S., Luo,~B P., Clegg,~S L., Peter,~T., Brimblecombe,~P., and Crutzen,~P J.: Stratospheric aerosol growth and \chemHNO_3 gas phase depletion from coupled \chemHNO_3 and water uptake by liquid particles, Geophys. Res. Lett., 21, 2479–2482, 1994.

Carlsaw,~K S., Luo,~B P., and Peter,~T.: An analytic expression for the composition of aqueous \chemHNO_3-\chemH_2SO_4 stratospheric aerosols including gas phase removal of \chemHNO_3, Geophys. Res. Lett., 22, 1877–1880, 1995.

Carslaw,~K S., Peter,~T., and Clegg,~S L.: Modeling the composition of liquid stratospheric aerosols, Rev. Geophys., 35, 125–154, 1997.

Carslaw,~K S., Wirth,~M., Tsias,~A., Luo,~B P., Dörnbrack,~A., Leutbecher,~M., Volkert,~H., Renger,~W., Bacmeister,~J T., Reimer,~E., and Peter,~T.: Increased stratospheric ozone depletion due to mountain-induced atmospheric waves, Nature, 391, 675–678, 1998.

Carslaw,~K S., Kettleborough,~J A., Northway,~M J., Davies,~S., Gao,~R.-S., Fahey,~D W., Baumgardner,~D G., Chipperfield,~M P., and Kleinböhl,~A.: A~vortex-scale simulation of the growth and sedimentation of large nitric acid hydrate particles,~J. Geophys. Res., 107, 8300, http://dx.doi.org/10.1029/2001JD000467doi:10.1029/2001JD000467, 2002.

Daneva,~D., Shibata,~T., Iwasaka,~Y., Nagatani,~M., Shiraishi,~K., Hayashi,~M., Fujiwara,~M., and Neuber,~R.: The mixing state of polar stratospheric cloud particles in sandwich structure observed by lidar 1. Determination of the mixing state of PSC particles,~J. Meteorol. Soc. Japan, 8, 747–757, 2003.

Danilin,~M Y., Ko,~M K W., Froidevaux,~L., Santee,~M L., Lyjak,~L V., Bevilacqua,~R M., Zawodny,~J M., Sasano,~Y., Irie,~H., Kondo,~Y., Russell,~J M., Scott,~C J., and Read,~W G.: Trajectory hunting as an effective technique to validate multiplatform measurements: analysis of the MLS, HALOE, SAGE-II, ILAS, and POAM-II data in October–November 1996,~J. Geophys. Res., 107, 4420, http://dx.doi.org/10.1029/2001JD002012doi:10.1029/2001JD002012, 2002.

Dhaniyala,~S., McKinney,~K A., and Wennberg,~P O.: Lee-wave clouds and denitrification of the polar stratosphere, Geophys. Res. Lett., 29, 36, http://dx.doi.org/10.1029/2001GL013900doi:10.1029/2001GL013900, 2002.

Dibb,~J E., Scheuer,~E., Avery,~M., Plant,~J., and Sachse,~G.: In situ evidence for renitrification in the Arctic lower stratosphere during the polar Aura validation experiment (PAVE), Geophys. Res. Lett., 33, L12815, http://dx.doi.org/10.1029/2006GL026243doi:10.1029/2006GL026243, 2006.

Drdla,~K., Schoeberl,~M R., and Browell,~E V.: Microphysical modeling of the 1999–2000 Arctic winter: 1. Polar stratospheric clouds, denitrification, and dehydration,~J. Geophys. Res., 107, 8312, http://dx.doi.org/10.1029/2001JD000782doi:10.1029/2001JD000782, 2002.

Drdla,~K., Gandrud,~B W., Baumgardner,~D., Wilson,~J C., Bui,~T P., Hurst,~D., Schauffler,~S M., Jost,~H., Greenblatt,~J B., and Webster,~C R.: Evidence for the widespread presence of liquid-phase particles during the 1999–2000 Arctic winter,~J. Geophys. Res., 108, 8318, http://dx.doi.org/10.1029/2001JD001127doi:10.1029/2001JD001127, 2003.

Dye,~J E., Baumgardner,~D., Gandrud,~B W., Kawa,~S R., Kelly,~K K., Loewenstein,~M., Ferry,~G V., Chan,~K R., and Gary,~B L.: Particle size distributions in Arctic polar stratospheric clouds, growth and freezing of sulfuric acid droplets, and implications for cloud formation,~J. Geophys. Res., 97, 8015–8034, 1992.

Dye,~J E., Baumgardner,~D., Gandrud,~B W., Drdla,~K., Barr,~K., Fahey,~D W., Delnegro,~L A., Tabazadeh,~A., Jonsson,~H H., Wilson,~J C., Loewenstein,~M., Podolske,~J R., and Chan,~K R.: In-situ observations of an Antarctic polar stratospheric cloud: similarities with Arctic observations, Geophys. Res. Lett., 23, 1913–1916, 1996.

% Eckermann,~S D., Wu,~D L., Doyle,~J D., Burris,~J F., McGee,~T J., Hostetler,~C A., Coy,~L., Lawrence,~B N., Stephens,~A., McCormack,~J P., and Hogan,~T F.: Imaging gravity waves in lower stratospheric AMSU-A radiances, Part 2: Validation case study, Atmos. Chem. Phys., 6, 3343–3362, 2006. % ### SELF-REFERENCE ### Eckermann,~S D., Wu,~D L., Doyle,~J D., Burris,~J F., McGee,~T J., Hostetler,~C A., Coy,~L., Lawrence,~B N., Stephens,~A., McCormack,~J P., and Hogan,~T F.: Imaging gravity waves in lower stratospheric AMSU-A radiances, Part 2: Validation case study, Atmos. Chem. Phys., 6, 3343–3362, http://dx.doi.org/10.5194/acp-6-3343-2006doi:10.5194/acp-6-3343-2006, 2006.

Eckermann,~S D., Hoffmann,~L., Hoepfner,~M., Wu,~D L., and Alexander,~M J.: Antarctic NAT PSC belt of June 2003: Observational validation of the mountain wave seeding hypothesis, Geophys. Res. Lett., 36, L02807, http://dx.doi.org/10.1029/2008GL036629doi:10.1029/2008GL036629, 2009.

Fahey,~D W., Kelly,~K K., Kawa,~S R., Tuck,~A F., Loewenstein,~M., Chan,~K R., and Heidt,~L E.: Observations of denitrification and dehydration in the winter polar stratospheres, Nature, 344, 321–324, 1990.

Fahey,~D W., Gao,~R S., Carslaw,~K S., Kettleborough,~J., Popp,~P J., Northway,~M J., Holecek,~J C., Ciciora,~S C., McLaughlin,~R J., Thompson,~T L., Winkler,~R H., Baumgardner,~D G., Gandrud,~B., Wennberg,~P O., Dhaniyala,~S., McKinney,~K., Peter,~T., Salawitch,~R J., Bui,~T P., Elkins,~J W., Webster,~C R., Atlas,~E L., Jost,~H., Wilson,~J C., Herman,~R L., Kleinbohl,~A., and von Konig,~M.: The detection of large \chemHNO_3-containing particles in the winter Arctic stratosphere, Science, 291, 1026–1031, 2001.

% 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., Koopman,~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. ### SELF-REFERENCE ### 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., Koopman,~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, http://dx.doi.org/10.5194/acp-8-2151-2008doi:10.5194/acp-8-2151-2008, 2008.

Fromm,~M., Alfred,~J., and Pitts,~M.: A~unified, long-term, high-latitude stratospheric aerosol and cloud database using SAM~II, SAGE~II, and POAM~II/III data: algorithm description, database definition, and climatology,~J. Geophys. Res., 108, 4366, http://dx.doi.org/10.1029/2002JD002772doi:10.1029/2002JD002772, 2003.

% Fueglistaler,~S., Luo,~B P., Voigt,~C., Carslaw,~K S., and Peter,~T.: NAT-rock formation by mother clouds: A~microphysical study, Atmos. Chem. Phys., 2, 93–98, 2002. % ### SELF-REFERENCE ### Fueglistaler,~S., Luo,~B P., Voigt,~C., Carslaw,~K S., and Peter,~Th.: NAT-rock formation by mother clouds: a microphysical model study, Atmos. Chem. Phys., 2, 93–98, http://dx.doi.org/10.5194/acp-2-93-2002doi:10.5194/acp-2-93-2002, 2002a.

Fueglistaler, S., Luo, B. P., Buss, S., Wernli, H., Voigt, C., Müller, M., Neuber, R., Hostetler, C. A., Poole, L. R., Flentje, H., Fahey, D. W., Northway, M. J., and Peter, Th.: Large NAT particle formation by mother clouds: analysis of SOLVE/THESEO-2000 observations, Geophys. Res. Lett., 29, 1610, http://dx.doi.org/10.1029/2001GL014548doi:10.1029/2001GL014548, 2002b.

Hanson,~D. and Mauersberger,~K.: Laboratory studies of the nitric acid trihydrate: implications for the south polar stratosphere, Geophys. Res. Lett., 15, 855–858, 1988.

Hatch,~C D., Gough,~R V., Toon,~O B., and Tolbert,~M A.: Heterogeneous nucleation of nitric acid trihydrate on clay minerals: relevance to type Ia polar stratopsheric clouds,~J. Phys. Chem B., 112, 612–620, http://dx.doi.org/10.1021/jp075828ndoi:10.1021/jp075828n, 2008.

Hervig,~M E.: Stratospheric clouds over England, Geophys. Res. Lett., 26, 1137–1140, 1999.

Hoffmann,~L. and Alexander,~M J.: Retrieval of stratospheric temperatures from Atmospheric Infrared Sounder radiance measurements for gravity wave studies,~J. Geophys. Res., 114, D07105, http://dx.doi.org/10.1029/2008JD011241doi:10.1029/2008JD011241, 2009.

Hofmann,~D J. and Deshler,~T.: Stratospheric cloud observations during formation of the Antarctic ozone hole in 1989,~J. Geophys. Res., 96, 2897–2912, 1991.

% Höpfner,~M., Larsen,~N., Spang,~R., Luo,~B P., Ma,~J., Svendsen,~S H., Eckermann,~S D., Knudsen,~B., Massoli,~P., Cairo,~F., Stiller,~G., Von~Clarmann,~T., and Fischer,~H.: MIPAS detects Antarctic stratospheric belt of NAT PSCs caused by mountain waves, Atmos. Chem. Phys., 6, 1221–1230, 2006. % ### SELF-REFERENCE ### Höpfner,~M., Larsen,~N., Spang,~R., Luo,~B P., Ma,~J., Svendsen,~S H., Eckermann,~S D., Knudsen,~B., Massoli,~P., Cairo,~F., Stiller,~G., v Clarmann,~T., and Fischer,~H.: MIPAS detects Antarctic stratospheric belt of NAT PSCs caused by mountain waves, Atmos. Chem. Phys., 6, 1221–1230, http://dx.doi.org/10.5194/acp-6-1221-2006doi:10.5194/acp-6-1221-2006, 2006a.

% Höpfner,~M., Luo,~B P., Massoli,~P., Cairo,~F., Spang,~R., Snels,~M., Di~Donfrancesco,~G., Stiller,~G., von Clarmann,~T., Fischer,~H., and Biermann,~U.: Spectroscopic evidence for NAT, STS, and ice in MIPAS infrared limb emission measurements of polar stratospheric clouds, Atmos. Chem. Phys., 6, 1201–1219, 2006. % ### SELF-REFERENCE ### Höpfner,~M., Luo,~B P., Massoli,~P., Cairo,~F., Spang,~R., Snels,~M., Di~Donfrancesco,~G., Stiller,~G., von~Clarmann,~T., Fischer,~H., and Biermann,~U.: Spectroscopic evidence for NAT, STS, and ice in MIPAS infrared limb emission measurements of polar stratospheric clouds, Atmos. Chem. Phys., 6, 1201–1219, http://dx.doi.org/10.5194/acp-6-1201-2006doi:10.5194/acp-6-1201-2006, 2006b.

Höpfner,~M., Pitts,~M C., and Poole,~L R.: Comparison between CALIPSO and MIPAS observations of polar stratospheric clouds,~J. Geophys. Res., 114, D00H05, http://dx.doi.org/10.1029/2009JD012114doi:10.1029/2009JD012114, 2009.

Hostetler,~C A., Liu,~Z., Reagan,~J., Vaughan,~M., Winker,~D., Osborn,~M., Hunt,~W H., Powell,~K A., and Trepte,~C.: CALIOP Algorithm Theoretical Basis Document: Calibration and Level 1 Products, Tech. rep., NASA Langley Research Center Document PC-SCI-201, Hampton, V A., available at: http://www-calipso.larc.nasa.gov/resources/pdfs/PC-SCI-201v1.0.pdf, last access:~October~2011, 2006.

Hu,~R.-M., Carslaw,~K S., Hostetler,~C., Poole,~L R., Luo,~B., Peter,~T., Füeglistaler,~S., McGee,~T J., and Burris,~J F.: Microphysical properties of wave polar stratospheric clouds retrieved from lidar measurements during SOLVE/THESEO 2000,~J. Geophys. Res., 107, 8294, http://dx.doi.org/10.1029/2001JD001125doi:10.1029/2001JD001125, 2002.

Hübler,~G., Fahey,~D W., Kelly,~K K., Montzka,~D D., Carroll,~M A., Tuck,~A F., Heidt,~L E., Pollock,~W H., Gregory,~G L., and Vedder,~J F.: Redistribution of reactive odd nitrogen in the lower Arctic stratosphere, Geophys. Res. Lett., 17, 453–456, 1990.

Hunt,~W H., Winker,~D M., Vaughan,~M A., Powell,~K A., Lucker,~P L., and Weimer,~C.: CALIPSO lidar description and performance assessment, J. Atmos. Oceanic Technol., 26, 1214–1228, http://dx.doi.org/10.1175/2009JTECHA1223.1doi:10.1175/2009JTECHA1223.1, 2009.

% Hurley,~J., Dudhia,~A., and Grainger,~R G.: Retrieval of macrophysical cloud parameters from MIPAS: algorithm description, Atmos. Meas. Tech., 4, 683–704, 2011. % ### SELF-REFERENCE ### Hurley,~J., Dudhia,~A., and Grainger,~R G.: Retrieval of macrophysical cloud parameters from MIPAS: algorithm description, Atmos. Meas. Tech., 4, 683–704, http://dx.doi.org/10.5194/amt-4-683-2011doi:10.5194/amt-4-683-2011, 2011.

Irie,~H., Koike,~M., Kondo,~Y., Bodeker,~G E., Danilin,~M Y., and Sasano,~Y.: Redistribution of nitric acid in the Arctic lower stratosphere during the winter of 1996–1997,~J. Geophys. Res., 106, 23139–23150, 2001.

Jarnot,~R F., Perun,~V S., and Schwartz,~M J.: Radiometric and spectral performance and calibration of the GHz bands of EOS MLS, IEEE T. Geosci. Remote, 44, 1131–1143, 2006.

Jensen,~E J., Toon,~O B., Tabazadeh,~A., and Drdla,~K.: Impact of polar stratospheric cloud particle composition, number density, and lifetime on denitrification,~J. Geophys. Res., 107, 8284, http://dx.doi.org/10.1029/2001JD000440doi:10.1029/2001JD000440, 2002.

Jin,~J J., Semeniuk,~K., Manney,~G L., Jonsson,~A I., Beagley,~S R., McConnell,~J C., Rinsland,~C P., Boone,~C D., Walker,~K A., and Bernath,~P F.: Denitrification in the Arctic winter 2004/2005: observations from ACE-FTS, Geophys. Res. Lett., 33, L19814, http://dx.doi.org/10.1029/2006GL027687doi:10.1029/2006GL027687, 2006.

Kinne,~S., Toon,~O B., Toon,~G C., Farmer,~C B., Browell,~E V., and McCormick,~M P.: Measurements of size and composition of particles in polar stratospheric clouds from infrared solar absorption spectra,~J. Geophys. Res., 94, 16481–16491, 1989.

Koike,~M., Kondo,~Y., Takegawa,~N., Lefevre,~F., Ikeda,~H., Irie,~H., Hunton,~H D E., Viggiano,~A A., Miller,~T M., Ballenthin,~J O., Sachse,~G W., Anderson,~B E., Avery,~M., and Masui,~Y.: Redistribution of reactive nitrogen in the Arctic lower stratosphere in the 1999/2000 winter, J. Geophys. Res., 107, 8275, http://dx.doi.org/10.1029/2001JD001089doi:10.1029/2001JD001089, 2002.

Kondo,~Y., Irie,~H., Koike,~M., and Bodeker,~G E.: Denitrification and nitrification in the Arctic stratosphere during the winter of 1996–1997, Geophys. Res. Lett., 27, 337–340, 2000.

Koop,~T., Carslaw,~K S., and Peter,~T.: Thermodynamic stability and phase transitions of PSC particles, Geophys. Res. Lett., 24, 2199–2202, 1997a.

Koop,~T., Luo,~B., Biermann,~U M., Crutzen,~P J., and Peter,~T.: Freezing of \chemHNO_3/\chemH_2SO_4/\chemH_2O solutions at stratospheric temperatures: nucleation statistics and experiments,~J. Phys. Chem. A, 101, 1117–1133, 1997b.

Koop,~T., Ng,~H P., Molina,~L T., and Molina,~M J.: A~new optical technique to study aerosol phase transitions: the nucleation of ice from \chemH_2SO_4 aerosols,~J. Phys. Chem. A, 102, 8924–8931, 1998.

Lambert,~A., Read,~W G., Livesey,~N J., Santee,~M L., Manney,~G L., Froidevaux,~L., Wu,~D L., Schwartz,~M J., Pumphrey,~H C., Jimenez,~C., Nedoluha,~G E., Cofield,~R E., Cuddy,~D T., Daffer,~W H., Drouin,~B J., Fuller,~R A., Jarnot,~R F., Knosp,~B W., Pickett,~H M., Perun,~V S., Snyder,~W V., Stek,~P C., Thurstans,~R P., Wagner,~P A., Waters,~J W., Jucks,~K W., Toon,~G C., Stachnik,~R A., Bernath,~P F., Boone,~C D., Walker,~K A., Urban,~J., Murtagh,~D., Elkins,~J W., and Atlas,~E.: Validation of the Aura Microwave Limb Sounder middle atmosphere water vapor and nitrous oxide measurements,~J. Geophys. Res., 112, D24S36, http://dx.doi.org/10.1029/2007JD008doi:10.1029/2007JD008, 2007.

Larsen,~N., Knudsen,~B M., Rosen,~J M., Kjome,~N T., Neuber,~R., and Kyrö,~E.: Temperature histories in liquid and solid polar stratospheric cloud formation,~J. Geophys. Res., 102, 23505–23517, 1997.

% Larsen,~N., Knudsen,~B., Svendsen,~S., Deshler,~T., Rosen,~J., Kivi,~R., Weisser,~C., Schreiner,~J., Mauerberger,~K., Cairo,~F., Ovarlez,~J., Oelhaf,~H., and Spang,~R.: Formation of solid particles in synoptic-scale Arctic PSCs in early winter 2002/2003, Atmos. Chem. Phys., 4, 2001–2013, 2004. % ### SELF-REFERENCE ### Larsen,~N., Knudsen,~B M., Svendsen,~S H., Deshler,~T., Rosen,~J M., Kivi,~R., Weisser,~C., Schreiner,~J., Mauerberger,~K., Cairo,~F., Ovarlez,~J., Oelhaf,~H., and Spang,~R.: Formation of solid particles in synoptic-scale Arctic PSCs in early winter 2002/2003, Atmos. Chem. Phys., 4, 2001–2013, http://dx.doi.org/10.5194/acp-4-2001-2004doi:10.5194/acp-4-2001-2004, 2004.

Liu,~L. and Mishchenko,~M I.: Constraints on PSC particle microphysics derived from lidar observations,~J. Quant. Spectrosc. Ra., 70, 817–831, http://dx.doi.org/10.1016/S0022-4073(01)00048-6doi:10.1016/S0022-4073(01)00048-6, 2001.

Livesey,~N J., Snyder,~W V., Read,~W G., and Wagner,~P A.: Retrieval algorithms for the EOS Microwave Limb Sounder (MLS), IEEE T. Geosci. Remote, 44, 1144–1155, 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.: Version 2.2 Level~2 data quality and description document, Tech. Rep. JPL D-32381, Jet Propulsion Laboratory, available at: http://mls.jpl.nasa.gov., last access:~October~2011, 2008.

Livesey,~N J., Read,~W G., Froidevaux,~L., Lambert,~A., Manney,~G L., Pumphrey,~H C., Santee,~M L., Schwartz,~M J., Wang,~S., Cofield,~R E., Cuddy,~D T., Fuller,~R A., Jarnot,~R F., Jiang,~J H., Knosp,~B W., Stek,~P C., Wagner,~P A., and Wu,~D L.: Version 3.3 Level~3 data quality and description document, Tech. Rep. JPL D-33509, Jet Propulsion Laboratory, available at: http://mls.jpl.nasa.gov., last access:~October~2011, 2011.

Lowe,~D. and MacKenzie,~A R.: Polar stratospheric cloud microphysics and chemistry,~J. Atmos. Solar-Terr. Phys., 70, 13–40, http://dx.doi.org/10.1016/j.jastp.2007.09.011doi:10.1016/j.jastp.2007.09.011, 2008.

% Lowe,~D., MacKenzie,~A R., Schlager,~H., Voigt,~C., Dörnbrack,~A., Mahoney,~M J., and Cairo,~F.: Liquid particle composition and heterogeneous reactions in a~mountain wave Polar Stratospheric Cloud, Atmos. Chem. Phys., 6, 3611–3623, 2006. % ### SELF-REFERENCE ### Lowe,~D., MacKenzie,~A R., Schlager,~H., Voigt,~C., Dörnbrack,~A., Mahoney,~M J., and Cairo,~F.: Liquid particle composition and heterogeneous reactions in a mountain wave Polar Stratospheric Cloud, Atmos. Chem. Phys., 6, 3611–3623, http://dx.doi.org/10.5194/acp-6-3611-2006doi:10.5194/acp-6-3611-2006, 2006.

Massie,~S., Dye,~J., Baumgardner,~D., Randel,~W., Wu,~F., Tie,~X., Pan,~L., Figarol,~F., Brasseur,~G., Santee,~M., Read,~W., Grainger,~R., Lambert,~A., Mergenthaler,~J., and Tabazadeh,~A.: Simultaneous observations of polar stratospheric clouds and \chemHNO_3 over Scandinavia in January, 1992, Geophys. Res. Lett., 24, 595–598, 1997.

% McDonald,~A J., George,~S E., and Woollands,~R M.: Can gravity waves significantly impact PSC occurrence in the Antarctic?, Atmos. Chem. Phys., 9, 8825–8840, 2009. % ### SELF-REFERENCE ### McDonald,~A J., George,~S E., and Woollands,~R M.: Can gravity waves significantly impact PSC occurrence in the Antarctic?, Atmos. Chem. Phys., 9, 8825–8840, http://dx.doi.org/10.5194/acp-9-8825-2009doi:10.5194/acp-9-8825-2009, 2009.

McKinney,~K., Wennberg,~P., Dhaniyala,~S., Fahey,~D., Northway,~M., Kunzi,~K., Kleinbohl,~A., Sinnhuber,~M., Kullmann,~H., Bremer,~H., Mahoney,~M., and Bui,~T.: Trajectory studies of large \chemHNO_3-containing PSC particles in the Arctic: evidence for the role of NAT, Geophys. Res. Lett., 31, L05110, http://dx.doi.org/10.1029/2003GL018430doi:10.1029/2003GL018430, 2004.

Meilinger,~S K., Koop,~T., Luo,~B P., Huthwelker,~T., Carslaw,~K S., Krieger,~U., Crutzen,~P J., and Peter,~T.: Size-dependent stratospheric droplet composition in lee wave temperature fluctuations and their potential role in PSC freezing, Geophys. Res. Lett., 22, 3031–3034, 1995.

Mishchenko,~M I. and Travis,~L D.: Capabilities and limitations of a~current FORTRAN implementation of the $T$-matrix method for randomly oriented, rotationally symmetric scatterers,~J. Quant. Spectrosc. Ra., 60, 309–324, http://dx.doi.org/10.1016/S0022-4073(98)00008-9doi:10.1016/S0022-4073(98)00008-9, 1998.

Murphy,~D M. and Koop,~T.: Review of the vapour pressures of ice and supercooled water for atmospheric applications,~Q J. Roy. Meteor. Soc., 131, 1539–1565, 2005.

Noel,~V., Hertzog,~A., Chepfer,~H., and Winker,~D M.: Polar stratospheric clouds over Antarctica from the CALIPSO spaceborne lidar,~J. Geophys. Res., 113, D02205, http://dx.doi.org/10.1029/2007JD008616doi:10.1029/2007JD008616, 2008.

Noel,~V., Hertzog,~A., and Chepfer,~H.: CALIPSO observations of wave-induced PSCs with near-unity optical depth over Antarctica in 2006–2007,~J. Geophys. Res., 114, D05202, http://dx.doi.org/10.1029/2008JD010604doi:10.1029/2008JD010604, 2009.

Northway,~M J., Gao,~R S., Popp,~P J., Holecek,~J C., Fahey,~D W., Carslaw,~K S., Tolbert,~M A., Lait,~L R., Dhaniyala,~S., Flagan,~R C., Wennberg,~P O., Mahoney,~M J., Herman,~R L., Toon,~G C., and Bui,~T P.: An analysis of large \chemHNO_3-containing particles sampled in the Arctic stratosphere during the winter of 1999/2000,~J. Geophys. Res., 107, 8298, http://dx.doi.org/10.1029/2001JD001079doi:10.1029/2001JD001079, 2002.

Pagan,~K L., Tabazadeh,~A., Drdla,~K., Hervig,~M E., Eckermann,~S D., Browell,~E V., Legg,~M J., and Foschi,~P G.: Observational evidence against mountain-wave generation of ice nuclei as a~prerequisite for the formation of three solid nitric acid polar stratospheric clouds observed in the Arctic in early December 1999,~J. Geophys. Res., 109, D04312, http://dx.doi.org/10.1029/2003JD003846doi:10.1029/2003JD003846, 2004.

Peter,~T.: Microphysics and heterogeneous chemistry of polar stratospheric clouds, Annu. Rev. Phys. Chem., 48, 785–822, 1997.

Peter,~T., Müller,~R., Crutzen,~P J., and Deshler,~T.: The lifetime of leewave-induced ice particles in the Arctic stratosphere: II, Stabilization due to NAT-coating, Geophys. Res. Lett., 21, 1331–1334, 1994.

% Pitts,~M C., Thomason,~L W., Poole,~L R., and Winker,~D M.: Characterization of polar stratospheric clouds with space-borne lidar: CALIPSO and the 2006 Antarctic season, Atmos. Chem. Phys., 7, 5207–5228, 2007. % ### SELF-REFERENCE ### Pitts,~M C., Thomason,~L W., Poole,~L R., and Winker,~D M.: Characterization of Polar Stratospheric Clouds with spaceborne lidar: CALIPSO and the 2006 Antarctic season, Atmos. Chem. Phys., 7, 5207–5228, http://dx.doi.org/10.5194/acp-7-5207-2007doi:10.5194/acp-7-5207-2007, 2007.

% Pitts,~M C., Poole,~L R., and Thomason,~L W.: CALIPSO polar stratospheric cloud observations: second-generation detection algorithm and composition discrimination, Atmos. Chem. Phys., 9, 7577–7589, 2009. % ### SELF-REFERENCE ### Pitts,~M C., Poole,~L R., and Thomason,~L W.: CALIPSO polar stratospheric cloud observations: second-generation detection algorithm and composition discrimination, Atmos. Chem. Phys., 9, 7577–7589, http://dx.doi.org/10.5194/acp-9-7577-2009doi:10.5194/acp-9-7577-2009, 2009.

Pitts, M. C., Poole, L. R., Dörnbrack, A., and Thomason, L. W.: The 2009–2010 Arctic polar stratospheric cloud season: a CALIPSO perspective, Atmos. Chem. Phys., 11, 2161–2177, http://dx.doi.org/10.5194/acp-11-2161-2011doi:10.5194/acp-11-2161-2011, 2011.

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., Vomel,~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, http://dx.doi.org/10.1029/2007JD008752doi:10.1029/2007JD008752, 2007.

Reichardt,~J., Reichardt,~S., Yang,~P., and McGee,~T J.: Retrieval of polar stratospheric cloud microphysical properties from lidar measurements: dependence on particle shape assumptions,~J. Geophys. Res., 107, 8282, http://dx.doi.org/10.1029/2001JD001021doi:10.1029/2001JD001021, 2002.

Reichardt, J., Dörnbrack, A., Reichardt, S., Yang, P., and McGee, T. J.: Mountain wave PSC dynamics and microphysics from ground-based lidar measurements and meteorological modeling, Atmos. Chem. Phys., 4, 1149–1165, http://dx.doi.org/10.5194/acp-4-1149-2004doi:10.5194/acp-4-1149-2004, 2004.

Ricaud,~P D., Carr,~E S., Harwood,~R S., Lahoz,~W A., Froidevaux,~L., Read,~W G., Waters,~J W., Mergenthaler,~J L., Kumer,~J B., Roche,~A E., and Peckham,~G E.: Polar stratospheric clouds as deduced from MLS and CLAES measurements, Geophys. Res. Lett., 22, 2033–2036, 1995.

Rienecker,~M M., Suarez,~M J., Todling,~R., Bacmeister,~K., Takacs,~L., Liu,~H.-C., Gu,~W., Sienkiewicz,~M., Koster,~R D., Gelaro,~R., Stajner,~I., and Nielsen,~J E.: The GEOS-5 Data Assimilation System - Documentation of Versions 5.0.1, 5.1.0, and 5.2.0, Tech. Rep., NASA Goddard Space Flight Center, Greenbelt, MD., NASA/TM-2008-10406, Vol. 27, 2008.

Rodgers,~C D.: Inverse Methods for Atmospheric Sounding: Theory and Practice, World Sci., Singapore, 2000.

Santee,~M L., Manney,~G L., Livesey,~N J., and Waters,~J W.: UARS Microwave Limb Sounder observations of denitrification and ozone loss in the 2000 Arctic late winter, Geophys. Res. Lett., 27, 3213–3216, 2000.

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 \chemHNO_3 measurements,~J. Geophys. Res., 112, D24S40, http://dx.doi.org/10.1029/2007JD008doi:10.1029/2007JD008, 2007.

Schoeberl,~M R., Douglass,~A R., Hilsenrath,~E., Bhartia,~P K., Beer,~R., Waters,~J W., Gunson,~M R., Froidevaux,~L., Gille,~J C., Barnett,~J J., Levelt,~P., and DeCola,~P.: Overview of the EOS Aura mission, IEEE T. Geosci. Remote, 44, 1066–1074, 2006.

Schwartz,~M J., Manney,~G L., Lambert,~A., Read,~W G., Livesey,~N J., Waters,~J W., Wu,~D L., Froidevaux,~L., Ao,~C O., Cofield,~R E., Daffer,~W H., Drouin,~B J., Fetzer,~E J., Fuller,~R A., Jarnot,~R F., Jiang,~J H., Jiang,~Y B., Knosp,~B W., Li,~J.-L F., Santee,~M L., Snyder,~W V., Stek,~P C., Thurstans,~R P., Wagner,~P A., Pawson,~S., Bernath,~P F., Walker,~K A., Boone,~C D., III,~J M R., Mlynczak,~M G., Li,~J.-L F., Krüger,~K., and Tompkins,~A M.: Validation of the Aura Microwave Limb Sounder temperature and geopotential height measurements,~J. Geophys. Res., 113, D15S11, http://dx.doi.org/10.1029/2007JD008783doi:10.1029/2007JD008783, 2008.

Solomon,~S.: Stratospheric ozone depletion: a~review of concepts and history, Rev. Geophys., 37, 275–316, 1999.

Spang,~R. and Remedios,~J J.: Observations of a~distinctive infrared spectral feature in the atmospheric spectra of polar stratospheric clouds measured by the CRISTA instrument, Geophys. Res. Lett., 30, 1875, http://dx.doi.org/10.1029/2003GL017doi:10.1029/2003GL017, 2003.

Spang,~R., Remedios,~J J., and Barkley,~M P.: Colour indices for the detection and differentiation of cloud types in infra-red limb emision spectra, Adv. Space Res., 33, 1041–1047, 2004.

Steele,~H M., Lumpe,~J D., Bevilacqua,~R M., Hoppel,~K W., and Turco,~R P.: Role of temperature history in polar stratospheric cloud sightings, J. Geophys. Res., 107, 4618, http://dx.doi.org/10.1029/2001JD001261doi:10.1029/2001JD001261, 2002.

Stefanutti,~L., Morandi,~M., Del~Guasta,~M., Godin,~S., and David,~C.: Unusual PSCs observed by LIDAR in Antarctica, Geophys. Res. Lett., 22, 2377–2380, 1995.

Tabazadeh,~A., Santee,~M L., Danilin,~M Y., Pumphrey,~H C., Newman,~P A., Hamill,~P J., and Mergenthaler,~J L.: Quantifying denitrification and its effect on ozone recovery, Science, 288, 1407–1411, 2000.

Tabazadeh,~A., Jensen,~E J., Toon,~O B., Drdla,~K., and Schoeberl,~M R.: Role of the stratospheric polar freezing belt in denitrification, Science, 291, 2591–2594, 2001.

Taesler, I., Delaplane, R G., and Olovsson, I.: Hydrogen bond studies. XCIV. Diaquaoxonium ion in nitric acid trihydrate, Acta Crystallogr., Sect. B, 31, 1489–1495, http://dx.doi.org/10.1107/S056774087500550Xdoi:10.1107/S056774087500550X, 1975.

Taylor,~F., Lambert,~A., Grainger,~R., Rodgers,~C., and Remedios,~J.: Properties of Northern Hemisphere polar stratospheric clouds and volcanic aerosol in 1991/92 from UARS/ISAMS satellite measurements,~J. Atmos. Sci., 51, 3019–3026, 1994.

100

Teitelbaum,~H., Moustaoui,~M., and Fromm,~M.: Exploring polar stratospheric cloud and ozone minihole formation: the primary importance of synoptic-scale flow perturbations,~J. Geophys. Res., 106, 28173–28188, 2001.

101

Thomason, L. W., Burton, S. P., Luo, B.-P., and Peter, T.: SAGE II measurements of stratospheric aerosol properties at non-volcanic levels, Atmos. Chem. Phys., 8, 983–995, http://dx.doi.org/10.5194/acp-8-983-2008doi:10.5194/acp-8-983-2008, 2008.

102

Toon,~O B., Browell,~E V., Kinne,~S., and Jordan,~J.: An analysis of lidar observations of polar stratospheric clouds, Geophys. Res. Lett., 17, 393–396, 1990.

103

Toon,~O B., Tabazadeh,~A., Browell,~E V., and Jordan,~J.: Analysis of lidar observations of Arctic polar stratospheric clouds during January 1989,~J. Geophys. Res., 105, 20589–20615, 2000.

104

Tsias,~A., Wirth,~M., Carslaw,~K., Biele,~J., Mehrtens,~H., Reichardt,~J., Wedekind,~C., Weiss,~V., Renger,~W., Neuber,~R., von Zahn,~U., Stein,~B., Santacesaria,~V., Stefanutti,~L., Fierli,~F., Bacmeister,~J., and Peter,~T.: Aircraft lidar observations of an enhanced type~Ia~polar stratospheric cloud during APE-POLECAT,~J. Geophys. Res., 104, 23961–23969, 1999.

105

Vernier,~J P., Pommereau,~J P., Garnier,~A., Pelon,~J., Larsen,~N., Nielsen,~J., Christiansen,~T., Cairo,~F., Thomason,~L W., Leblanc,~T., and McDermid,~I S.: Tropical stratospheric aerosol layer from CALIPSO lidar observations,~J. Geophys. Res., 114, D00H10, http://dx.doi.org/10.1029/2009JD011doi:10.1029/2009JD011, 2009.

106

Voigt,~C., Schreiner,~J., Kohlmann,~A., Zink,~P., Mauersberger,~K., Larsen,~N., Deshler,~T., Kroger,~C., Rosen,~J., Adriani,~A., Cairo,~F., Di~Donfrancesco,~G., Viterbini,~M., Ovarlez,~J., Ovarlez,~H., David,~C., and Dornbrack,~A.: Nitric acid trihydrate (NAT) in polar stratospheric clouds, Science, 290, 1756–1758, 2000a.

107

Voigt,~C., Tsias,~A., Dörnbrack,~A., Meilinger,~S., Luo,~B., Schreiner,~J., Larsen,~N., Mauersberger,~K., and Peter,~T.: Non-equilibrium compositions of liquid polar stratospheric clouds in gravity waves, Geophys. Res. Lett., 27, 3873–3876, 2000b.

108

% Voigt,~C., Schlager,~H., Luo,~B P., Dornbrack,~A D., Roiger,~A., Stock,~P., Curtius,~J., Vossing,~H., Borrmann,~S., Davies,~S., Konopka,~P., Schiller,~C., Shur,~G., and Peter,~T.: Nitric Acid Trihydrate (NAT) formation at low NAT supersaturation in Polar Stratospheric Clouds (PSCs), Atmos. Chem. Phys., 5, 1371–1380, 2005. % ### SELF-REFERENCE ### Voigt,~C., Schlager,~H., Luo,~B P., Dörnbrack,~A., Roiger,~A., Stock,~P., Curtius,~J., Vössing,~H., Borrmann,~S., Davies,~S., Konopka,~P., Schiller,~C., Shur,~G., and Peter,~T.: Nitric Acid Trihydrate (NAT) formation at low NAT supersaturation in Polar Stratospheric Clouds (PSCs), Atmos. Chem. Phys., 5, 1371–1380, http://dx.doi.org/10.5194/acp-5-1371-2005doi:10.5194/acp-5-1371-2005, 2005.

109

von König,~M., Bremer,~H., Kleinbohl,~A., Kullmann,~H., Kunzi,~K F., Goede,~A P H., Browell,~E V., Grant,~W B., Burris,~J F., McGee,~T J., and Twigg,~L.: Using gas-phase nitric acid as an indicator of PSC composition,~J. Geophys. Res., 107, 8265, http://dx.doi.org/10.1029/2001JD001041doi:10.1029/2001JD001041, 2002.

110

Wagner, R., Möhler, O., Saathoff, H., Stetzer, O., and Schurath, U.: Infrared Spectrum of Nitric Acid Dihydrate: Influence of Particle Shape, J. Phys. Chem. A, 109, 2572–2581, http://dx.doi.org/10.1021/jp044997udoi:10.1021/jp044997u, 2005.

111

% Wang,~D Y., Hoepfner,~M H., Tsidu,~G M., 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., Lopez-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, 2007. % ### SELF-REFERENCE ### 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, http://dx.doi.org/10.5194/acp-7-721-2007doi:10.5194/acp-7-721-2007, 2007.

112

Wang,~Z., Stephens,~G., Deshler,~T., Trepte,~C., Parish,~T., Vane,~D., Winker,~D., Liu,~D., and Adhikari,~L.: Association of Antarctic polar stratospheric cloud formation on tropospheric cloud systems, Geophys. Res. Lett., 35, L13806, http://dx.doi.org/10.1029/2008GL034209doi:10.1029/2008GL034209, 2008.

113

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 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., Chen,~G S., Chudasama,~B V., Dodge,~R., Fuller,~R A., Girard,~M A., Jiang,~J H., Jiang,~Y B., 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., Van~Snyder,~W., 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, 2006.

114

Winker,~D M., Vaughan,~M A., Omar,~A., Hu,~Y., Powell,~K A., Liu,~Z., Hunt,~W H., and Young,~S A.: Overview of the CALIPSO Mission and CALIOP data processing algorithms,~J. Atmos. Oceanic Technol., 26, 2310–2323, http://dx.doi.org/10.1175/2009JTECHA1281.1doi:10.1175/2009JTECHA1281.1, 2009.

115

Wofsy,~S C., Salawitch,~R J., Yatteau,~J H., McElroy,~M B., Gandrud,~B W., Dye,~J E., and Baumgardner,~D.: Condensation of \chemHNO_3 on falling ice particles: Mechanism for denitrification of the polar stratosphere, Geophys. Res. Lett., 17, 449–452, 1990.

116

Worsnop,~D R., Fox,~L E., Zahniser,~M S., and Wofsy,~S C.: Vapor pressures of solid hydrates of nitric acid: Implications for polar stratospheric clouds, Science, 259, 71–74, 1993.

117

% Wu,~D L., Chae,~J H., Lambert,~A., and Zhang,~F F.: Characteristics of CALIOP attenuated backscatter noise: implication for cloud/aerosol detection, Atmos. Chem. Phys., 11, 2641–2654, 2011. % ### SELF-REFERENCE ### Wu,~D L., Chae,~J H., Lambert,~A., and Zhang,~F F.: Characteristics of CALIOP attenuated backscatter noise: implication for cloud/aerosol detection, Atmos. Chem. Phys., 11, 2641–2654, http://dx.doi.org/10.5194/acp-11-2641-2011doi:10.5194/acp-11-2641-2011, 2011.

118

% Yu,~F.: Formation of large NAT particles and denitrification in polar stratosphere: possible role of cosmic rays and effect of solar activity, Atmos. Chem. Phys., 4, 2273–2283, 2004. % ### SELF-REFERENCE ### Yu,~F.: Formation of large NAT particles and denitrification in polar stratosphere: possible role of cosmic rays and effect of solar activity, Atmos. Chem. Phys., 4, 2273–2283, http://dx.doi.org/10.5194/acp-4-2273-2004doi:10.5194/acp-4-2273-2004, 2004.

119

Zondlo,~M., Hudson,~P., Prenni,~A., and Tolbert,~M.: Chemistry and microphysics of polar stratospheric clouds and cirrus clouds, Ann. Rev. Phys. Chem., 51, 473–499, 2000.