Abstract
Abstract. A focus of the Arctic Research of the Composition of the Troposphere from Aircraft and Satellites (ARCTAS) mission was examination of bromine photochemistry in the spring time high latitude troposphere based on aircraft and satellite measurements of bromine oxide (BrO) and related species. The NASA DC-8 aircraft utilized a chemical ionization mass spectrometer (CIMS) to measure BrO and a mist chamber (MC) to measure soluble bromide. We have determined that the MC detection efficiency to molecular bromine (Br2), hypobromous acid (HOBr), bromine oxide (BrO), and hydrogen bromide (HBr) as soluble bromide (Br−) was 0.9±0.1, 1.06+0.30/−0.35, 0.4±0.1, and 0.95±0.1, respectively. These efficiency factors were used to estimate soluble bromide levels along the DC-8 flight track of 17 April 2008 from photochemical calculations constrained to in situ BrO measured by CIMS. During this flight, the highest levels of soluble bromide and BrO were observed and atmospheric conditions were ideal for the space-borne observation of BrO. The good agreement (R2 = 0.76; slope = 0.95; intercept = −3.4 pmol mol−1) between modeled and observed soluble bromide, when BrO was above detection limit (>2 pmol mol−1) under unpolluted conditions (NO<10 pmol mol−1), indicates that the CIMS BrO measurements were consistent with the MC soluble bromide and that a well characterized MC can be used to derive mixing ratios of some reactive bromine compounds. Tropospheric BrO vertical column densities (BrOVCD) derived from CIMS BrO observations compare well with BrOTROPVCD from OMI on 17 April 2008.
Highlights
Tropospheric ozone depletion events (ODEs) have frequently been observed in or near the marine boundary layer in the Arctic (e.g. Oltmans, 1981; Bottenheim et al, 2009) and the Antarctic (e.g. Jones et al, 2009) during spring time
Characterization of the mist chamber (MC) response to gas phase bromine species enables better use of soluble bromide data from previous and future field missions focusing on polar halogen chemistry
As hypobromous acid (HOBr) converts to Br2 on surfaces, the detection efficiency of HOBr as soluble bromide by MC can vary with inlet length
Summary
Tropospheric ozone depletion events (ODEs) have frequently been observed in or near the marine boundary layer in the Arctic (e.g. Oltmans, 1981; Bottenheim et al, 2009) and the Antarctic (e.g. Jones et al, 2009) during spring time. Tropospheric ozone depletion events (ODEs) have frequently been observed in or near the marine boundary layer in the Arctic The ODEs can extend over horizontal scales of hundreds of kilometers (Ridley et al, 2003) and vertically from the surface to altitudes as high as several hundred meters to ∼1 km (Bottenheim et al, 2002; Ridley et al, 2003). In ODEs ozone mixing ratios drop from typical 30–40 nmol mol−1 to as low as 1 nmol mol−1 (e.g. Bottenheim et al, 2009 and 2002; Anlauf et al, 1994). The oxidation of certain volatile organic compounds (VOCs) can be enhanced during ODEs The oxidation of certain volatile organic compounds (VOCs) can be enhanced during ODEs (e.g. Jobson et al, 1994)
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
