Aura MLS

HCl

Contact: Lucien Froidevaux

HCl in the stratosphere (from 15 to 50 km altitude) is a gas that results from the decomposition (by UV radiation) of tropospheric sources gases, mainly chlorofluorocarbons (CFCs).

Most of the chlorine that is released from CFCs stored in this HCl reservoir at high altitudes (near 50 km), and HCl in the upper stratosphere provides a measure of the total chlorine content of the atmosphere (an abundance close to 3.5 parts per billion by volume).

The chemistry that leads to ozone depletion at high latitudes largely comes from the more reactive forms of gaseous chlorine (mainly as ClO or chlorine monoxide, also measured by MLS), which makes up all or a large fraction of the atmospheric chlorine content in the lower stratosphere (near 20 km altitude) during polar winter and spring.

Some chlorine at high altitude (near 40 km) is also in the form of ClO, which participates in ozone depletion as well. HCl is converted to ClO at high altitude, mainly by reaction with the OH radical; methane (CH4) reacting with chlorine atoms reforms HCl.

A steady-state balance in the concentrations of active and reservoir chlorine molecules is achieved. Chlorine nitrate (ClONO2) also plays a role as a temporary chlorine reservoir, usually with lower abundances than HCl.

How it is part of MLS Science Objectives

One of the objectives for MLS and the Aura mission is to understand and follow changes in the chemistry and atmospheric composition that can affect stratospheric ozone.

HCl in the upper stratosphere has now been decreasing (since about the turn of the century), based on expectations from measurements of CFCs at the ground as well as past satellite HCl data and column HCl measurements from ground-based infrared data.

MLS has observed a global decrease in upper stratospheric HCl, confirming that international agreements to limit the production of CFCs is having an impact on the total available stratospheric chlorine abundance (more than 95% of stratospheric chlorine at high altitude is in the form of gaseous HCl).

Since early 2006, however, the main band for measuring HCl has been used very infrequently because of rapid deterioration in this specific portion of the MLS instrument; this does not diminish the usefulness/quality of other MLS data, including HCl measurements in the lower stratosphere (below about 30km altitude), as these measurements (from another band) have continued on a daily basis.

In the lower stratosphere during polar winter and spring, the MLS measurements of HCl and ClO provide important information about the partitioning of chlorine products critical to ozone depletion.

How EOS MLS measures HCl

Retrievals of the HCl standard product (fromthe 640GHz radiometer) use channels from band 14, as a result of the deterioration observed since early 2006 in nearby band 13, originally targeted (with narrower channels than band 14) at the main HCl emission line center.

HCl Information from the Spectroscopy Database

Quick Product Information for data version v5

  • Swath Name: HCl
  • Status Flag: Only use profiles for which the Status field is an even number.
  • Useful Range: 100 - 0.32 hPa
  • DAAC Short Name: ML2HCL
  • Precision: Only use values for which the estimated precision is a positive number.
  • Quality Threshold: >1.2
  • Convergence Threshold: <1.05

Download Aura MLS HCl v5 data

Latest Publications (HCl)

  1. Blunden, J. and T. Boyer
    State of the Climate in 2021
    Bull. Am. Meteorol. Soc. doi:10.1175/2022bamsstateoftheclimate.1, 2022
  2. Millán, L., M.L. Santee, A. Lambert, N.J. Livesey, F. Werner, M.J. Schwartz, H.C. Pumphrey, G.L. Manney, Y. Wang, H. Su, L. Wu, W.G. Read and L. Froidevaux
    The Hunga Tonga-Hunga Ha'apai Hydration of the Stratosphere
    Geophys. Res. Lett. doi:10.1029/2022gl099381, 2022
  3. Salawitch, R. and L. McBride
    Australian wildfires depleted the ozone layer
  4. Santee, M.L., A. Lambert, G.L. Manney, N.J. Livesey, L. Froidevaux, J.L. Neu, M.J. Schwartz, L.F. Millán, F. Werner, W.G. Read, M. Park, R.A. Fuller and B.M. Ward
    Prolonged and Pervasive Perturbations in the Composition of the Southern Hemisphere Midlatitude Lower Stratosphere From the Australian New Year's Fires
    Geophys. Res. Lett. doi:10.1029/2021gl096270, 2022
  5. Strahan, S., D. Smale, S. Solomon, G. Taha, M. Damon, S. Steenrod, N. Jones, B. Liley, R. Querel and J. Robinson
    Unexpected Repartitioning of Stratospheric Inorganic Chlorine After the 2020 Australian Wildfires
    Geophys. Res. Lett. doi:10.1029/2022gl098290, 2022
  6. Feng, W., S. Dhomse, C. Arosio, M. Weber, J. Burrows, M. Santee and M. Chipperfield
    Arctic Ozone Depletion in 2019/20: Roles of Chemistry, Dynamics and the Montreal Protocol
    Geophys. Res. Lett. doi:10.1029/2020gl091911, 2021
  7. Grooß, J. and R. Müller
    Simulation of Record Arctic Stratospheric Ozone Depletion in 2020
    Journal of Geophysical Research: Atmospheres doi:10.1029/2020jd033339, 2021
  8. Shan, C., H. Zhang, W. Wang, C. Liu, Y. Xie, Q. Hu and N. Jones
    Retrieval of Stratospheric HNO3 and HCl Based on Ground-Based High-Resolution Fourier Transform Spectroscopy
    Remote Sens. doi:10.3390/rs13112159, 2021
  9. Sukhodolov, T., T. Egorova, A. Stenke, W. Ball, C. Brodowsky, G. Chiodo, A. Feinberg, M. Friedel, A. Karagodin-Doyennel, T. Peter, J. Sedlacek, S. Vattioni and E. Rozanov
    Atmosphere–ocean–aerosol–chemistry–climate model SOCOLv4.0: description and evaluation
    Geoscientific Model Development doi:10.5194/gmd-14-5525-2021, 2021
  10. von Gathen, P.D., R. Kivi, I. Wohltmann, R. Salawitch and M. Rex
    Climate change favours large seasonal loss of Arctic ozone
    Nature Communications doi:10.1038/s41467-021-24089-6, 2021
  11. Wilkerson, J., D. Sayres, J. Smith, N. Allen, M. Rivero, M. Greenberg, T. Martin and J. Anderson
    In situ observations of stratospheric HCl using three-mirror integrated cavity output spectroscopy
    Atmospheric Measurement Techniques doi:10.5194/amt-14-3597-2021, 2021
  12. Barrera, J., R. Fernandez, F. Iglesias-Suarez, C. Cuevas, J. Lamarque and A. Saiz-Lopez
    Seasonal impact of biogenic very short-lived bromocarbons on lowermost stratospheric ozone between 60° N and 60° S during the 21st century
    Atmos. Chem. Phys. doi:10.5194/acp-20-8083-2020, 2020
  13. Han, Y., F. Xie and J. Zhang
    Has Stratospheric HCl in the Northern Hemisphere Been Increasing Since 2005?
    Front. Earth Sci. doi:10.3389/feart.2020.609411, 2020
  14. Inness, A., S. Chabrillat, J. Flemming, V. Huijnen, B. Langenrock, J. Nicolas, I. Polichtchouk and M. Razinger
    Exceptionally Low Arctic Stratospheric Ozone in Spring 2020 as Seen in the CAMS Reanalysis
    Journal of Geophysical Research: Atmospheres doi:10.1029/2020jd033563, 2020
  15. Manney, G., N. Livesey, M. Santee, L. Froidevaux, A. Lambert, Z. Lawrence, L. Millán, J. Neu, W. Read, M. Schwartz and R. Fuller
    Record‐Low Arctic Stratospheric Ozone in 2020: MLS Observations of Chemical Processes and Comparisons With Previous Extreme Winters
    Geophys. Res. Lett. 10.1029/2020gl089063, 2020
  16. Nakajima, H., I. Murata, Y. Nagahama, H. Akiyoshi, K. Saeki, T. Kinase, M. Takeda, Y. Tomikawa, E. Dupuy and N. Jones
    Chlorine partitioning near the polar vortex edge observed with ground-based FTIR and satellites at Syowa Station, Antarctica, in 2007 and 2011
    Atmos. Chem. Phys. doi:10.5194/acp-20-1043-2020, 2020
  17. Nara, S., T. Sato, T. Yamada, T. Fujinawa, K. Kuribayashi, T. Manabe, L. Froidevaux, N. Livesey, K. Walker, J. Xu, F. Schreier, Y. Orsolini, V. Limpasuvan, N. Kuno and Y. Kasai
    Validation of SMILES HCl profiles over a wide range from the stratosphere to the lower thermosphere
    Atmospheric Measurement Techniques doi:10.5194/amt-13-6837-2020, 2020
  18. Strahan, S., D. Smale, A. Douglass, T. Blumenstock, J. Hannigan, F. Hase, N. Jones, E. Mahieu, J. Notholt, L. Oman, I. Ortega, M. Palm, M. Prignon, J. Robinson, M. Schneider, R. Sussmann and V. Velazco
    Observed Hemispheric Asymmetry in Stratospheric Transport Trends From 1994 to 2018
    Geophys. Res. Lett. doi:10.1029/2020gl088567, 2020
  19. Wargan, K., B. Weir, G. Manney, S. Cohn and N. Livesey
    The Anomalous 2019 Antarctic Ozone Hole in the GEOS Constituent Data Assimilation System With MLS Observations
    Journal of Geophysical Research: Atmospheres doi:10.1029/2020jd033335, 2020
  20. Blunden, J. and D. Arndt
    State of the Climate in 2018
    Bull. Am. Meteorol. Soc. doi:10.1175/2019bamsstateoftheclimate.1, 2019
  21. Errera, Q., S. Chabrillat, Y. Christophe, J. Debosscher, D. Hubert, W. Lahoz, M. Santee, M. Shiotani, S. Skachko, T. von Clarmann and K. Walker
    Technical note: Reanalysis of Aura MLS chemical observations
    Atmos. Chem. Phys. doi:10.5194/acp-19-13647-2019, 2019
  22. Froidevaux, L., D. Kinnison, R. Wang, J. Anderson and R. Fuller
    Evaluation of CESM1 WACCM free-running and specified dynamics atmospheric composition simulations using global multispecies satellite data records
    Atmos. Chem. Phys. doi:10.5194/acp-19-4783-2019, 2019
  23. Han, Y., W. Tian, M. Chipperfield, J. Zhang, F. Wang, W. Sang, J. Luo, W. Feng, A. Chrysanthou and H. Tian
    Attribution of the Hemispheric Asymmetries in Trends of Stratospheric Trace Gases Inferred from Microwave Limb Sounder MLS Measurements
    Journal of Geophysical Research: Atmospheres doi:10.1029/2018jd029723, 2019
  24. Johansson, S., M. Santee, J. Grooß, M. Höpfner, M. Braun, F. Friedl-Vallon, F. Khosrawi, O. Kirner, E. Kretschmer, H. Oelhaf, J. Orphal, B. Sinnhuber, I. Tritscher, J. Ungermann, K. Walker and W. Woiwode
    Unusual chlorine partitioning in the 2015/16 Arctic winter lowermost stratosphere: observations and simulations
    Atmos. Chem. Phys. doi:10.5194/acp-19-8311-2019, 2019
  25. Li, X., J. Xu, T. Cheng, H. Shi, X. Zhang, S. Ge, H. Wang, S. Zhu, J. Miao and Q. Luo
    Monitoring Trace Gases over the Antarctic Using Atmospheric Infrared Ultraspectral Sounder Onboard GaoFen-5: Algorithm Description and First Retrieval Results of O3, H2O, and HCl
    Remote Sens. doi:10.3390/rs11171991, 2019
  26. Anderson, J.G. and C.E. Clapp
    Coupling free radical catalysis, climate change, and human health
    Physical Chemistry Chemical Physics doi:10.1039/c7cp08331a, 2018
  27. Bernath, P. and A. Fernando
    Trends in stratospheric HCl from the ACE satellite mission
    J. Quant. Spectrosc. Radiat. Transfer doi:10.1016/j.jqsrt.2018.05.027, 2018
  28. Dhomse, S., D. Kinnison, M. Chipperfield, R. Salawitch, I. Cionni, M. Hegglin, N.L. Abraham, H. Akiyoshi, A. Archibald, E. Bednarz, S. Bekki, P. Braesicke, N. Butchart, M. Dameris, M. Deushi, S. Frith, S. Hardiman, B. Hassler, L. Horowitz, R. Hu, P. Jöckel, B. Josse, O. Kirner, S. Kremser, U. Langematz, J. Lewis, M. Marchand, M. Lin, E. Mancini, V. Marécal, M. Michou, O. Morgenstern, F. O&ampaposConnor, L. Oman, G. Pitari, D. Plummer, J. Pyle, L. Revell, E. Rozanov, R. Schofield, A. Stenke, K. Stone, K. Sudo, S. Tilmes, D. Visioni, Y. Yamashita and G. Zeng
    Estimates of ozone return dates from Chemistry-Climate Model Initiative simulations
    Atmos. Chem. Phys. doi:10.5194/acp-18-8409-2018, 2018
  29. Grooß, J., R. Müller, R. Spang, I. Tritscher, T. Wegner, M. Chipperfield, W. Feng, D. Kinnison and S. Madronich
    On the discrepancy of HCl processing in the core of the wintertime polar vortices
    Atmos. Chem. Phys. doi:10.5194/acp-18-8647-2018, 2018
  30. Kreyling, D., I. Wohltmann, R. Lehmann and M. Rex
    The Extrapolar SWIFT model version 1.0: fast stratospheric ozone chemistry for global climate models
    Geoscientific Model Development doi:10.5194/gmd-11-753-2018, 2018
  31. Steinbrecht, W., M. Hegglin, N. Harris and M. Weber
    Is global ozone recovering?
    Comptes Rendus Geoscience doi:10.1016/j.crte.2018.07.012, 2018
  32. Stolarski, R., A. Douglass and S. Strahan
    Using satellite measurements of N2O to remove dynamical variability from HCl measurements
    Atmos. Chem. Phys. doi:10.5194/acp-18-5691-2018, 2018
  33. Strahan, S. and A. Douglass
    Decline in Antarctic Ozone Depletion and Lower Stratospheric Chlorine Determined From Aura Microwave Limb Sounder Observations
    Geophys. Res. Lett. doi:10.1002/2017gl074830, 2018
  34. Xu, J., F. Schreier, G. Wetzel, A.D. Lange, M. Birk, T. Trautmann, A. Doicu and G. Wagner
    Performance Assessment of Balloon-Borne Trace Gas Sounding with the Terahertz Channel of TELIS
    Remote Sens. doi:10.3390/rs10020315, 2018
  35. Anderson, J., D. Weisenstein, K. Bowman, C. Homeyer, J. Smith, D. Wilmouth, D. Sayres, J.E. Klobas, S. Leroy, J. Dykema and S. Wofsy
    Stratospheric ozone over the United States in summer linked to observations of convection and temperature via chlorine and bromine catalysis
    Proc. Nat. Acad. Sci. doi:10.1073/pnas.1619318114, 2017
  36. Hegglin, M., S. Tegtmeier, J. Anderson, A. Bourassa, S. Brohede, D. Degenstein, L. Froidevaux, B. Funke, J. Gille, A. Jones, Y. Kasai, E. Kyrola, J. Lumpe, J. Neu, E. Remsberg, A. Rozanov, M. Toohey, J. Urban, T. von Clarmann, K.A. Walker and R. Wang
    The SPARC Data Initiative: Assessment of stratospheric trace gas and aerosol climatologies from satellite limb sounders
  37. Ochiai, S., P. Baron, T. Nishibori, Y. Irimajiri, Y. Uzawa, T. Manabe, H. Maezawa, A. Mizuno, T. Nagahama, H. Sagawa, M. Suzuki and M. Shiotani
    SMILES-2 Mission for Temperature, Wind, and Composition in the Whole Atmosphere
  38. Santee, M.L., G.L. Manney, N.J. Livesey, M.J. Schwartz, J.L. Neu and W.G. Read
    A comprehensive overview of the climatological composition of the Asian summer monsoon anticyclone based on 10 years of Aura Microwave Limb Sounder measurements
    Journal of Geophysical Research: Atmospheres doi:10.1002/2016jd026408, 2017
  39. Tweedy, O., N. Kramarova, S. Strahan, P. Newman, L. Coy, W. Randel, M. Park, D. Waugh and S. Frith
    Response of trace gases to the disrupted 2015–2016 quasi-biennial oscillation
    Atmos. Chem. Phys. doi:10.5194/acp-17-6813-2017, 2017
  40. Wohltmann, I., R. Lehmann and M. Rex
    A quantitative analysis of the reactions involved in stratospheric ozone depletion in the polar vortex core
    Atmos. Chem. Phys. doi:10.5194/acp-17-10535-2017, 2017
  41. Wohltmann, I., R. Lehmann and M. Rex
    Update of the Polar SWIFT model for polar stratospheric ozone loss Polar SWIFT version 2
    Geosci. Model Dev. doi:10.5194/gmd-10-2671-2017, 2017
  42. Akiyoshi, H., T. Nakamura, T. Miyasaka, M. Shiotani and M. Suzuki
    A nudged chemistry-climate model simulation of chemical constituent distribution at northern high-latitude stratosphere observed by SMILES and MLS during the 2009/2010 stratospheric sudden warming
    Journal of Geophysical Research: Atmospheres doi:10.1002/2015jd023334, 2016
  43. Andersson, M.E., P.T. Verronen, D.R. Marsh, S.M. Paivarinta and J.M.C. Plane
    WACCM-D-Improved modeling of nitric acid and active chlorine during energetic particle precipitation
    Journal of Geophysical Research: Atmospheres doi:10.1002/2015jd024173, 2016
  44. Carn, S.A., L. Clarisse and A.J. Prata
    Multi-decadal satellite measurements of global volcanic degassing
    J. Volcanology Geotherm. Res. doi:10.1016/j.jvolgeores.2016.01.002, 2016
  45. Huijnen, V., J. Flemming, S. Chabrillat, Q. Errera, Y. Christophe, A. Blechschmidt, A. Richter and H. Eskes
    C-IFS-CB05-BASCOE: stratospheric chemistry in the Integrated Forecasting System of ECMWF
    Geosci. Model Dev. doi:10.5194/gmd-9-3071-2016, 2016
  46. Manney, G. and Z. Lawrence
    The major stratospheric final warming in 2016: dispersal of vortex air and termination of Arctic chemical ozone loss
    Atmos. Chem. Phys. 10.5194/acp-16-15371-2016, 2016
  47. Millan, L., N. Livesey, M. Santee, J. Neu, G. Manney and R. Fuller
    Case studies of the impact of orbital sampling on stratospheric trend detection and derivation of tropical vertical velocities: solar occultation vs. limb emission sounding
    Atmos. Chem. Phys. doi:10.5194/acp-16-11521-2016, 2016
  48. Nakajima, H., I. Wohltmann, T. Wegner, M. Takeda, M.C. Pitts, L.R. Poole, R. Lehmann, M.L. Santee and M. Rex
    Polar Stratospheric Cloud evolution and chlorine activation measured by CALIPSO and MLS, and modelled by ATLAS
    Atmos. Chem. Phys. doi:10.5194/acp-16-3311-2016, 2016
  49. Skachko, S., R. Menard, Q. Errera, Y. Christophe and S. Chabrillat
    EnKF and 4D-Var data assimilation with chemical transport model BASCOE version 05.06
    Geosci. Model Dev. doi:10.5194/gmd-9-2893-2016, 2016
  50. Wegner, T., M. Pitts, L. Poole, I. Tritscher, J. Grooß and H. Nakajima
    Vortex-wide chlorine activation by a mesoscale PSC event in the Arctic winter of 2009/10
    Atmos. Chem. Phys. doi:10.5194/acp-16-4569-2016, 2016
  51. Froidevaux, L., J. Anderson, H.J. Wang, R.A. Fuller, M.J. Schwartz, M.L. Santee, N.J. Livesey, H.C. Pumphrey, P.F. Bernath, J.M. Russell III and M.P. McCormick
    Global OZone Chemistry And Related trace gas Data records for the Stratosphere GOZCARDS: methodology and sample results with a focus on HCl, H2O, and O3
    Atmos. Chem. Phys. doi:10.5194/acp-15-10471-2015, 2015
  52. Guo, D., Y. Su, C. Shi, J. Xu and A. Powell
    Double core of ozone valley over the Tibetan Plateau and its possible mechanisms
    J. Atmos. Solar-Terr. Phys. doi:10.1016/j.jastp.2015.05.018, 2015
  53. Kristiansen, N.I., A.J. Prata, A. Stohl and S.A. Carn
    Stratospheric volcanic ash emissions from the 13 February 2014 Kelut eruption
    Geophys. Res. Lett. doi:10.1002/2014GL062307, 2015
  54. Kuttippurath, J., S. Godin-Beekmann, F. Lefevre, M.L. Santee, L. Froidevaux and A. Hauchecorne
    Variability in Antarctic ozone loss in the last decade 2004-2013: high-resolution simulations compared to Aura MLS observations
    Atmos. Chem. Phys. doi:10.5194/acp-15-10385-2015, 2015
  55. Manney, G., Z. Lawrence, M. Santee, W. Read, N. Livesey, A. Lambert, L. Froidevaux, H. Pumphrey and M. Schwartz
    A minor sudden stratospheric warming with a major impact: Transport and polar processing in the 2014/2015 Arctic winter
    Geophys. Res. Lett. doi:10.1002/2015gl065864, 2015
  56. Manney, G.L., Z.D. Lawrence, M.L. Santee, N.J. Livesey, A. Lambert and M.C. Pitts
    Polar processing in a split vortex: Arctic ozone loss in early winter 2012/2013
    Atmos. Chem. Phys. doi:10.5194/acp-15-5381-2015, 2015
  57. Pendlebury, D., D. Plummer, J. Scinocca, P. Sheese, K. Strong, K. Walker and D. Degenstein
    Comparison of the CMAM30 data set with ACE-FTS and OSIRIS: polar regions
    Atmos. Chem. Phys. doi:10.5194/acp-15-12465-2015, 2015
  58. Schwartz, M.J., G.L. Manney, M.I. Hegglin, N.J. Livesey, M.L. Santee and W.H. Daffer
    Climatology and variability of trace gases in extratropical double-tropopause regions from MLS, HIRDLS, and ACE-FTS measurements
    Journal of Geophysical Research: Atmospheres doi:10.1002/2014JD021964, 2015
  59. Solomon, S., D. Kinnison, J. Bandoro and R. Garcia
    Simulation of polar ozone depletion: An update
    Journal of Geophysical Research: Atmospheres doi:10.1002/2015jd023365, 2015
  60. Tang, X., Y. Liu, W. Wang, L. Song and W. Li
    Changes in stratospheric ClO and HCl concentrations under different greenhouse gas emission scenarios
    J Meteorol Res doi:10.1007/s13351-015-4065-3, 2015
  61. Blunden, J. and D.S. Arndt
    State of the Climate in 2013
    Bull. Am. Meteorol. Soc. 2014
  62. Damiani, A., B. Funke, M.L. Puertas, A. Gardini, T. von Clarmann, M.L. Santee, L. Froidevaux and R.R. Cordero
    Changes in the composition of the northern polar upper stratosphere in February 2009 after a sudden stratospheric warming
    Journal of Geophysical Research: Atmospheres doi:10.1002/2014JD021698, 2014
  63. Hurst, D.F., A. Lambert, W.G. Read, S.M. Davis, K.H. Rosenlof, E.G. Hall, A.F. Jordan and S.J. Oltmans
    Validation of Aura Microwave Limb Sounder stratospheric water vapor measurements by the NOAA frost point hygrometer
    Journal of Geophysical Research: Atmospheres doi:10.1002/2013JD020757, 2014
  64. Mahieu, E., M.P. Chipperfield, J. Notholt, T. Reddmann, J. Anderson, P.F. Bernath, T. Blumenstock, M.T. Coffey, S.S. Dhomse, W. Feng, B. Franco, L. Froidevaux, D. Griffith, J.W. Hannigan, F. Hase, R. Hossaini, N.B. Jones, I. Morino, I. Murata, H. Nakajima, M. Palm, C. Paton-Walsh, J.M. Russell III, M. Schneider, C. Servais, D. Smale and K.A. Walker
    Recent Northern Hemisphere stratospheric HCl increase due to atmospheric circulation changes
  65. Theys, N., I.D. Smedt, M.V. Roozendael, L. Froidevaux, L. Clarisse and F. Hendrick
    First satellite detection of volcanic OClO after the eruption of Puyehue-Cordón Caulle
    Geophys. Res. Lett. doi:10.1002/2013GL058416, 2014
  66. Virolainen, Y., Y. Timofeyev, A. Polyakov, D. Ionov and A. Poberovsky
    Intercomparison of satellite and ground-based measurements of ozone, NO2, HF, and HCl near Saint Petersburg, Russia
    Int. Jnl. Remote Sensing doi:10.1080/01431161.2014.945009, 2014
  67. Blunden, J. and D.S. Arndt
    State of the Climate in 2012
    Bull. Am. Meteorol. Soc. 2013
  68. Khosravi, M., P. Baron, J. Urban, L. Froidevaux, A.I. Jonsson, Y. Kasai, K. Kuribayashi, C. Mitsuda, D.P. Murtagh, H. Sagawa, M.L. Santee, T.O. Sato, M. Shiotani, M. Suzuki, T. von Clarmann, K.A. Walker and S. Wang
    Diurnal variation of stratospheric and lower mesospheric HOCl, ClO and HO2 at the equator: comparison of 1-D model calculations with measurements by satellite instruments
    Atmos. Chem. Phys. doi:10.5194/acp-13-7587-2013, 2013
  69. Schwartz, M.J., W.J. Read, M.L. Santee, N.J. Livesey, L. Froidevaux, A. Lambert and G.L. Manney
    Convectively Injected Water Vapor in the North American Summer Lowermost Stratosphere
    Geophys. Res. Lett. doi:10.1002/grl.50421, 2013
  70. Sugita, T., Y. Kasai, Y. Terao, S. Hayashida, G.L. Manney, W.H. Daffer, H. Sagawa, M. Suzuki, M. Shiotani, K.A. Walker, C.D. Boone and P.F. Bernath
    HCl and ClO profiles inside the Antarctic vortex as observed by SMILES in November 2009: comparisons HCl and ClO profiles inside the Antarctic vortex as observed by SMILES in November 2009: comparisons with MLS and ACE-FTS instruments
    Atmospheric Measurement Techniques doi:10.5194/amt-6-3099-2013, 2013
  71. von Clarmann, T.
    Chlorine in the stratosphere
  72. Wohltmann, I., T. Wegner, R. Mueller, R. Lehmann, M. Rex, G.L. Manney, M.L. Santee, P. Bernath, O. Suminska-Ebersoldt, F. Strohl, M. von Hobe, C.M. Volk, E. Hoesen, F. Ravegnani, A. Ulanovsky and V. Yushkov
    Uncertainties in modelling heterogeneous chemistry and Arctic ozone depletion in the winter 2009/2010
    Atmos. Chem. Phys. doi:10.5194/acp-13-3909-2013, 2013
  73. Blessmann, D., I. Wohldmann, R. Lehmann and M. Rex
    Persistence of ozone anomalies in the Arctic stratospheric vortex in autumn
    Atmos. Chem. Phys. doi:10.5194/acp-12-4817-2012, 2012
  74. Blunden, J. and D.S. Arndt
    State of the Climate in 2011
    Bull. Am. Meteorol. Soc. doi:10.1175/2012BAMSStateoftheClimate.1, 2012
  75. Damiani, A., B. Funke, D.R. Marsh, M. Lopez-Puertas, M.L. Santee, L. Froidevaux, S. Wang, C.H. Jackman, T. von Clarmann, A. Gardini, R.R. Cordero and M. Storini
    Impact of January 2005 solar proton events on chlorine species
    Atmos. Chem. Phys. doi:10.5194/acp-12-4159-2012, 2012
  76. Jones, A., K.A. Walker, J.J. Jin, J.R. Taylor, C.D. Boone, P.F. Bernath, S. Brohede, G.L. Manney, S. McLeod, R. Hughes and W.H. Daffer
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