A new interpretation of total column BrO during Arctic spring

Emission of bromine from sea‐salt aerosol, frost flowers, ice leads, and snow results in the nearly complete removal of surface ozone during Arctic spring. Regions of enhanced total column BrO observed by satellites have traditionally been associated with these emissions. However, airborne measurements of BrO and O3 within the convective boundary layer (CBL) during the ARCTAS and ARCPAC field campaigns at times bear little relation to enhanced column BrO. We show that the locations of numerous satellite BrO “hotspots” during Arctic spring are consistent with observations of total column ozone and tropopause height, suggesting a stratospheric origin to these regions of elevated BrO. Tropospheric enhancements of BrO large enough to affect the column abundance are also observed, with important contributions originating from above the CBL. Closure of the budget for total column BrO, albeit with significant uncertainty, is achieved by summing observed tropospheric partial columns with calculated stratospheric partial columns provided that natural, short‐lived biogenic bromocarbons supply between 5 and 10 ppt of bromine to the Arctic lowermost stratosphere. Proper understanding of bromine and its effects on atmospheric composition requires accurate treatment of geographic variations in column BrO originating from both the stratosphere and troposphere.

[1]  P. Shepson,et al.  A comparison of Arctic BrO measurements by chemical ionization mass spectrometry and long path‐differential optical absorption spectroscopy , 2011 .

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

[3]  Quintus Kleipool,et al.  Earth surface reflectance climatology from 3 years of OMI data , 2008 .

[4]  F. Daerden,et al.  A global stratospheric bromine monoxide climatology based on the BASCOE chemical transport model , 2008 .

[5]  R. Stolarski,et al.  Evaluation of emissions and transport of CFCs using surface observations and their seasonal cycles and the GEOS CCM simulation with emissions‐based forcing , 2008 .

[6]  K. Kreher,et al.  One‐decade trend analysis of stratospheric BrO over Harestua (60°N) and Lauder (45°S) reveals a decline , 2008 .

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

[8]  K. Chance,et al.  An ozone depletion event in the sub-arctic surface layer over Hudson Bay, Canada , 2007 .

[9]  Rolando R. Garcia,et al.  Simulation of secular trends in the middle atmosphere, 1950–2003 , 2007 .

[10]  Michael Sprenger,et al.  Identification and ERA-15 Climatology of Potential Vorticity Streamers and Cutoffs near the Extratropical Tropopause , 2007 .

[11]  D. Jacob,et al.  Global lifetime of elemental mercury against oxidation by atomic bromine in the free troposphere , 2006 .

[12]  R. Salawitch.  Atmospheric chemistry: Biogenic bromine , 2006, Nature.

[13]  D. Weisenstein,et al.  Sensitivity of ozone to bromine in the lower stratosphere , 2005 .

[14]  P. Crutzen,et al.  Impact of reactive bromine chemistry in the troposphere , 2004 .

[15]  G. Moore,et al.  Lake-Effect Snowstorms over Southern Ontario, Canada, and Their Associated Synoptic-Scale Environment , 2004 .

[16]  U. Platt,et al.  Ground‐based measurements of halogen oxides at the Hudson Bay by active longpath DOAS and passive MAX‐DOAS , 2004 .

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

[18]  K. Pfeilsticker,et al.  Spatial and temporal distribution of enhanced boundary layer BrO concentrations measured by the GOME instrument aboard ERS‐2 , 2001 .

[19]  D. Blake,et al.  Distributions of brominated organic compounds in the troposphere and lower stratosphere , 1999 .

[20]  C. T. McElroy,et al.  Evidence for bromine monoxide in the free troposphere during the Arctic polar sunrise , 1999, Nature.

[21]  Kelly Chance,et al.  Analysis of BrO measurements from the Global Ozone Monitoring Experiment , 1998 .

[22]  Michael Eisinger,et al.  GOME observations of tropospheric BrO in northern hemispheric spring and summer 1997 , 1998 .

[23]  D. Weisenstein,et al.  Distribution of halon-1211 in the upper troposphere and lower stratosphere and the 1994 total bromine budget , 1998 .

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

[25]  Sarit Kraus,et al.  Year-to-year variations of spring time polar tropospheric BrO as seen by GOME , 2004 .

[26]  V. L. Orkin,et al.  Chemical kinetics and photochemical data for use in atmospheric studies. Evaluation No. 14 (JPL Publication 02-25) , 2003 .

[27]  A. Sobel,et al.  Direct Diagnoses of Stratosphere–Troposphere Exchange , 2000 .