Chlorine activation and ozone depletion in the Arctic vortex: Observations by the Halogen Occultation Experiment on the Upper Atmosphere Research Satellite

Chlorine-catalyzed ozone destruction is clearly observed during austral spring in the Antarctic lower stratosphere. While high concentrations of ozone-destroying ClO radicals have likewise been measured during winter in the Arctic stratosphere, the chemical ozone depletion there is more difficult to quantify. Here we present observations of the Halogen Occultation Experiment on the Upper Atmosphere Research Satellite in the vortex region of the Arctic lower stratosphere during the winter and spring months of 1991/1992, 1992/1993, 1993/1994, and 1994/1995. All February measurements indicate an almost complete conversion of the otherwise main chlorine reservoir species HCl to chemically more reactive forms. Using CH4 as a chemically conserved tracer, we show that significant chemical ozone loss occurred in the Arctic vortex region during all four winters. The deficit in column ozone was about 60 and 50 Dobson units (DU) in the winters 1991/1992 and 1993/1994, respectively. During the two winters of 1992/1993 and 1994/1995 a severe chemical loss in lower-stratospheric ozone took place, with local reductions of the mixing ratios by over 50% and a loss in the column ozone of the order of 100 DU.

[1]  Christopher R. Webster,et al.  Validation of Halogen Occultation Experiment CH4 measurements from the UARS , 1996 .

[2]  S. R. Drayson,et al.  Halogen Occultation Experiment ozone channel validation , 1996 .

[3]  L. Froidevaux,et al.  Arctic ozone depletion observed by UARS MLS during the 1994-95 winter , 1996 .

[4]  M. Prather,et al.  Seasonal evolutions of N2O, O3, and CO2: Three‐dimensional simulations of stratospheric correlations , 1995 .

[5]  M. Rummukainen,et al.  Observational evidence for chemical ozone depletion over the Arctic in winter 1991–92 , 1995, Nature.

[6]  L. Froidevaux,et al.  UARS MLS observations of lower stratospheric ClO in the 1992-93 and 1993-94 Arctic winter vortices , 1995 .

[7]  D. Fahey,et al.  Estimates of total organic and inorganic chlorine in the lower stratosphere from in situ and flask measurements during AASE II , 1995 .

[8]  A. Tuck,et al.  Time and temperature dependences of fractional HCl abundances from airborne data in the Southern Hemisphere during 1994 , 1995 .

[9]  J. M. Reeves,et al.  Arctic chlorine monoxide observations during spring 1993 over Thule, Greenland, and implications for ozone depletion , 1994 .

[10]  J. Russell,et al.  Hydrochloric Acid and the Chlorine Budget of the Lower Stratosphere , 1994 .

[11]  A. J. Miller,et al.  The anomalous arctic lower stratospheric polar vortex of 1992-1993 , 1994 .

[12]  J. B. Kumer,et al.  Chemical depletion of ozone in the Arctic lower stratosphere during winter 1992–93 , 1994, Nature.

[13]  N. Larsen,et al.  Ozone depletion in the Arctic stratosphere in early 1993 , 1994 .

[14]  B. Naujokat,et al.  Correlation between stratospheric temperature, total ozone, and tropospheric weather systems , 1994 .

[15]  T. Blumenstock,et al.  First results of ground‐based FTIR measurements of atmospheric trace gases in north Sweden and Greenland during EASOE , 1994 .

[16]  J. Wolf,et al.  Stratospheric aerosol size distributions from multispectral lidar measurements at Sodankylä during EASOE , 1994 .

[17]  David John Lary,et al.  Box model studies of ClOx deactivation and ozone loss during the 1991/92 northern hemisphere winter , 1994 .

[18]  A. Engel,et al.  The variation of available chlorine, Cly, in the arctic polar vortex during EASOE , 1994 .

[19]  J. M. Reeves,et al.  An overview of millimeter‐wave spectroscopic measurements of chlorine monoxide at Thule, Greenland, February–March, 1992: Vertical profiles, diurnal variation, and longer‐term trends , 1994 .

[20]  J. Waters,et al.  Column measurements of stratospheric trace species over Åre, Sweden in the winter of 1991–1992 , 1994 .

[21]  Hermann Oelhaf,et al.  Stratospheric ClONO2 and HNO3 profiles inside the Arctic vortex from MIPAS-B limb emission spectra obtained during EASOE , 1994 .

[22]  David John Lary,et al.  Chlorine chemistry and the potential for ozone depletion in the Arctic stratosphere in the winter of 1991/92 , 1994 .

[23]  Mark R. Schoeberl,et al.  Intrusions into the lower stratospheric Arctic vortex during the winter of 1991–1992 , 1994 .

[24]  D. R. Hanson,et al.  Reaction of ClONO2 with HCl on NAT, NAD, and frozen sulfuric acid and hydrolysis of N2O5 and ClONO2 on frozen sulfuric acid , 1993 .

[25]  Hermann Oelhaf,et al.  Retrieval of stratospheric O3, HNO3 and ClONO2 profiles from 1992 MIPAS‐B limb emission spectra: Method, results, and error analysis , 1993 .

[26]  A. Weinheimer,et al.  AASE‐II in‐situ tracer correlations of methane, nitrous oxide, and ozone as observed aboard the DC‐8 , 1993 .

[27]  H. Jonsson,et al.  In‐situ measurements of changes in stratospheric aerosol and the N2O‐aerosol relationship inside and outside of the polar vortex , 1993 .

[28]  J. Notholt.  Stratospheric trace gas concentrations in the Arctic polar night derived by FTIR spectroscopy witgh the moon as IR light source , 1993 .

[29]  D. Fahey,et al.  The Seasonal Evolution of Reactive Chlorine in the Northern Hemisphere Stratosphere , 1993, Science.

[30]  D. Toohey,et al.  Chlorine Chemistry on Polar Stratospheric Cloud Particles in the Arctic Winter , 1993, Science.

[31]  S. Wofsy,et al.  Chemical Loss of Ozone in the Arctic Polar Vortex in the Winter of 1991-1992 , 1993, Science.

[32]  M. Loewenstein,et al.  Ozone Loss Inside the Northern Polar Vortex During the 1991-1992 Winter , 1993, Science.

[33]  W. Grant,et al.  Ozone and Aerosol Changes During the 1991-1992 Airborne Arctic Stratospheric Expedition , 1993, Science.

[34]  James M. Russell,et al.  The Halogen Occultation Experiment , 1993 .

[35]  L. Froidevaux,et al.  Stratospheric CIO and ozone from the Microwave Limb Sounder on the Upper Atmosphere Research Satellite , 1993, Nature.

[36]  Geoffrey C. Toon,et al.  Airborne observations of the 1992 arctic winter stratosphere by FTIR solar absorption spectroscopy , 1993, Other Conferences.

[37]  S. Solomon,et al.  Measurements and model calculations of HCl column amounts and related parameters over McMurdo during the austral spring in 1989 , 1992 .

[38]  Malcolm K. W. Ko,et al.  Interrelationships between mixing ratios of long‐lived stratospheric constituents , 1992 .

[39]  A. Dahlback,et al.  Analysis of the ozone soundings made during the first quarter of 1989 in the Arctic , 1992 .

[40]  D. Fahey,et al.  Polar stratospheric cloud processed air and potential voracity in the northern hemisphere lower stratosphere at mid‐latitudes during winter , 1992 .

[41]  C. B. Farmer,et al.  Composition measurements of the 1989 Arctic winter stratosphere by airborne infrared solar absorption spectroscopy , 1992 .

[42]  M. Molina,et al.  The heterogeneous reaction of HOCl + HCl ? Cl2 + H2O on ice and nitric acid trihydrate: Reaction pro , 1992 .

[43]  D. Fahey,et al.  The Potential for Ozone Depletion in the Arctic Polar Stratosphere , 1991, Science.

[44]  D. Goeddel,et al.  Selective activation of the B natriuretic peptide receptor by C-type natriuretic peptide (CNP). , 1991, Science.

[45]  D. R. Hanson,et al.  The reaction probabilities of ClONO2 and N2O5 on polar stratospheric cloud materials , 1991 .

[46]  D. Hofmann,et al.  Evidence from balloon measurements for chemical depletion of stratospheric ozone in the Arctic winter of 1989–90 , 1991, Nature.

[47]  D. Toohey,et al.  Free Radicals Within the Antarctic Vortex: The Role of CFCs in Antarctic Ozone Loss , 1991, Science.

[48]  K. Kelly,et al.  Ozone loss in the Arctic polar vortex inferred from high-altitude aircraft measurements , 1990, Nature.

[49]  S. Solomon.  Progress towards a quantitative understanding of Antarctic ozone depletion , 1990, Nature.

[50]  K. Kelly,et al.  Stratospheric constituent trends from ER-2 profile data , 1990 .

[51]  D. Toohey,et al.  In situ measurements of BrO in the Arctic stratosphere , 1990 .

[52]  S. Wofsy,et al.  Loss of ozone in the Arctic vortex for the winter of 1989 , 1990 .

[53]  Roderic L. Jones,et al.  Calculations of ozone destruction during the 1988/89 Arctic winter , 1990 .

[54]  A. Tuck,et al.  Airborne lidar observations in the wintertime Arctic stratosphere: Ozone , 1990 .

[55]  Roderic L. Jones,et al.  The polar stratospheric cloud event of January 24, 1989, part 1. Microphysics , 1990 .

[56]  W. Evans.  Ozone depletion in the Arctic Vortex at alert during February 1989 , 1990 .

[57]  Mark R. Schoeberl,et al.  Reconstruction of the constituent distribution and trends in the Antarctic polar vortex from ER‐2 flight observations , 1989 .

[58]  C. B. Farmer,et al.  Infrared aircraft measurements of stratospheric composition over Antarctica during September 1987 , 1989 .

[59]  K. Kelly,et al.  Correlation of N2O and ozone in the southern polar vortex during the Airborne Antarctic Ozone Experiment , 1989 .

[60]  M. H. Proffitt,et al.  High-latitude ozone loss outside the Antarctic ozone hole , 1989, Nature.

[61]  Roderic L. Jones,et al.  Diagnostic studies of the Antartctic vortex during the 1987 Airborne Antarctic Ozone Experiment: Ozone miniholes , 1989 .

[62]  L. Emmons,et al.  New observations of a large concentration of ClO in the springtime lower stratosphere over Antarctica and its implications for ozone-depleting chemistry , 1989 .

[63]  Y. Kondo,et al.  Stratospheric clouds and ozone depletion in the Arctic during January 1989 , 1989, Nature.

[64]  M. Molina,et al.  Antarctic Stratospheric Chemistry of Chlorine Nitrate, Hydrogen Chloride, and Ice: Release of Active Chlorine , 1987, Science.

[65]  C. B. Farmer,et al.  Stratospheric trace gases in the spring 1986 Antarctic atmosphere , 1987, Nature.

[66]  A. Dudhia,et al.  Proposed reference models for nitrous oxide and methane in the middle atmosphere , 1987 .

[67]  M. Molina,et al.  Production of Cl2O2 from the self-reaction of the ClO radical , 1987 .

[68]  S. Solomon,et al.  On the depletion of Antarctic ozone , 1986, Nature.

[69]  J. Farman,et al.  Large losses of total ozone in Antarctica reveal seasonal ClOx/NOx interaction , 1985, Nature.

[70]  John C. Gille,et al.  Transport of ozone in the middle stratosphere: evidence for planetary wave breaking , 1985 .

[71]  G. Dobson,et al.  Measurements of the amount of Ozone in the Earth's Atmosphere and its Relations to Other Geophysical Conditions. Part 21 , 1926 .