Interactive comment on “ Bromine measurements in ozone depleted air over the Arctic Ocean ” by J . A

In situ measurements of ozone, photochemically active bromine compounds, and other trace gases over the Arctic Ocean in April 2008 are used to examine the chemistry and geographical extent of ozone depletion in the arctic marine boundary layer (MBL). Data were obtained from the NOAA WP-3D aircraft during the Aerosol, Radiation, and Cloud Processes affecting Arctic Climate (ARCPAC) study and the NASA DC-8 aircraft during the Arctic Research of the Composition of the Troposphere from Aircraft and Satellites (ARCTAS) study. Fast (1 s) and sensitive (detection limits at the low pptv level) measurements of BrCl and BrO were obtained from three different chemical ionization mass spectrometer (CIMS) instruments, and soluble bromide was measured with a mist chamber. The CIMS instruments also detected Br 2. Subsequent laboratory studies showed that HOBr rapidly converts to Br 2 on the Teflon instrument inlets. This detected Br 2 is identified as active bromine and represents a lower limit of the sum HOBr + Br 2. The measured active bromine is shown to likely be HOBr during daytime flights in the arctic. In the MBL over the Arctic Ocean, soluble bromide and active bromine were consistently elevated and ozone was depleted. Ozone depletion and active bromine enhancement were confined to the MBL that was capped by a temperature inversion at 200–500 m altitude. In ozonedepleted air, BrO rarely exceeded 10 pptv and was always substantially lower than soluble bromide that was as high as 40 pptv. BrCl was rarely enhanced above the 2 pptv detection limit, either in the MBL, over Alaska, or in the arctic free troposphere. Correspondence to: J. A. Neuman (andy.neuman@noaa.gov)

[1]  L. Ziemba,et al.  Bromide and other ions in the snow, firn air, and atmospheric boundary layer at Summit during GSHOX , 2010 .

[2]  J. Peischl,et al.  Bromine measurements in ozone depleted air over the Arctic Ocean , 2010 .

[3]  Glenn E. Shaw,et al.  The Arctic Research of the Composition of the Troposphere from Aircraft and Satellites (ARCTAS) mission: design, execution, and first results , 2010 .

[4]  C. E. Jones,et al.  Measurement and modelling of tropospheric reactive halogen species over the tropical Atlantic Ocean , 2010 .

[5]  Glenn E. Shaw,et al.  The ARCTAS aircraft mission: design and execution , 2009 .

[6]  A. Richter,et al.  BrO, blizzards, and drivers of polar tropospheric ozone depletion events , 2009 .

[7]  A. Ravishankara,et al.  N2O5 Oxidizes Chloride to Cl2 in Acidic Atmospheric Aerosol , 2008, Science.

[8]  A. Lewis,et al.  Extensive halogen-mediated ozone destruction over the tropical Atlantic Ocean , 2008, Nature.

[9]  H. Skov,et al.  A synthesis of atmospheric mercury depletion event chemistry in the atmosphere and snow , 2008 .

[10]  Lars Kaleschke,et al.  Halogens and their role in polar boundary-layer ozone depletion , 2007 .

[11]  T. Bertram,et al.  Measurement of HO2NO2 in the free troposphere during the Intercontinental Chemical Transport Experiment–North America 2004 , 2007 .

[12]  L. G. Huey.  Measurement of trace atmospheric species by chemical ionization mass spectrometry: speciation of reactive nitrogen and future directions. , 2007, Mass spectrometry reviews.

[13]  P. Shepson,et al.  Chlorine and bromine atom ratios in the springtime Arctic troposphere as determined from measurements of halogenated volatile organic compounds , 2006 .

[14]  R. A. Cox,et al.  Tropospheric bromine chemistry and its impacts on ozone: A model study , 2005 .

[15]  J. Bottenheim,et al.  A trajectory study into the origin of spring time Arctic boundary layer ozone depletion , 2005 .

[16]  B. Cossairt,et al.  Temperature and pressure dependent rate coefficients for the reaction of Hg with Br and the reaction of Br with Br: a pulsed laser photolysis-pulsed laser induced fluorescence study. , 2005, The journal of physical chemistry. A.

[17]  G. Hönninger,et al.  A one dimensional model study of the mechanism of halogen liberation and vertical transport in the polar troposphere , 2004 .

[18]  F. Flocke,et al.  A thermal dissociation–chemical ionization mass spectrometry (TD‐CIMS) technique for the simultaneous measurement of peroxyacyl nitrates and dinitrogen pentoxide , 2004 .

[19]  G. Geernaert,et al.  Fate of elemental mercury in the Arctic during atmospheric mercury depletion episodes and the load of atmospheric mercury to the Arctic. , 2004, Environmental science & technology.

[20]  H. Skov,et al.  A theoretical study of the oxidation of Hg0 to HgBr2 in the troposphere. , 2004, Environmental science & technology.

[21]  J. Plane,et al.  Bromine oxide in the mid‐latitude marine boundary layer , 2004 .

[22]  K. Chance,et al.  Widespread persistent near‐surface ozone depletion at northern high latitudes in spring , 2003 .

[23]  S. Lindberg,et al.  A modeling study of the mechanism of the halogen-ozone-mercury homogeneous reactions in the troposphere during the polar spring , 2003 .

[24]  U. Platt,et al.  The role of halogen species in the troposphere. , 2003, Chemosphere.

[25]  D. Jacob,et al.  Coupled evolution of BrOx-ClOx-HOx-NOx chemistry during bromine- catalyzed ozone depletion events in the arctic boundary layer , 2003 .

[26]  D. Blake,et al.  Ozone depletion events observed in the high latitude surface layer during the TOPSE aircraft program , 2003 .

[27]  A. Weinheimer,et al.  Fast‐response airborne in situ measurements of HNO3 during the Texas 2000 Air Quality Study , 2002 .

[28]  P. Shepson,et al.  The role of Br2 and BrCl in surface ozone destruction at polar sunrise. , 2001, Science.

[29]  Paul B. Shepson,et al.  Measurements of Photolyzable Halogen Compounds and Bromine Radicals During the Polar Sunrise Experiment 1997 , 1999 .

[30]  Miguel Ángel Martínez,et al.  The role of bromine and chlorine chemistry for arctic ozone depletion events in Ny-Ålesund and comparison with model calculations , 1999 .

[31]  H. Bergh,et al.  Heterogeneous Kinetics of the Uptake of HOBr on Solid Alkali Metal Halides at Ambient Temperature , 1998 .

[32]  L. Barrie,et al.  Ozone and meteorology during the 1994 Polar Sunrise Experiment , 1998 .

[33]  U. Platt,et al.  DOAS-observation of halogen radical-catalysed arctic boundary layer ozone destruction during the ARCTOC-campaigns 1995 and 1996 in Ny-Ålesund, Spitsbergen , 1997 .

[34]  P. Shepson,et al.  Sources and sinks of carbonyl compounds in the Arctic Ocean boundary layer: Polar ice floe experiment , 1996 .

[35]  Paul J. Crutzen,et al.  Model study indicating halogen activation and ozone destruction in polluted air masses transported to the sea , 1996 .

[36]  D. R. Hanson,et al.  Reactions of SF- 6 and I- with Atmospheric Trace Gases. , 1995 .

[37]  W. Sturges,et al.  Lower tropospheric measurements of halogens, nitrates, and sulphur oxides during Polar Sunrise Experiment 1992 , 1994 .

[38]  P. Shepson,et al.  Airborne observations related to ozone depletion at polar sunrise , 1994 .

[39]  Y. Yokouchi,et al.  Measurements of C2‐C6 hydrocarbons during the Polar Sunrise1992 Experiment: Evidence for Cl atom and Br atom chemistry , 1994 .

[40]  M. Hausmann,et al.  Spectroscopic measurement of bromine oxide and ozone in the high Arctic during Polar Sunrise Experiment 1992 , 1994 .

[41]  D. Jacob,et al.  Surface ozone depletion in Arctic spring sustained by bromine reactions on aerosols , 1992, Nature.

[42]  P. Crutzen,et al.  Ozone destruction and photochemical reactions at polar sunrise in the lower Arctic atmosphere , 1988, Nature.

[43]  S. Oltmans.  Surface ozone measurements in clean air , 1981 .

[44]  Manfred Eigen,et al.  The Kinetics of Halogen Hydrolysis , 1962 .

[45]  S. Nghiem,et al.  Ozone in the boundary layer air over the Arctic Ocean: measurements during the TARA transpolar drift 2006–2008 , 2009 .