ACE-FTS observations of acetonitrile in the lower stratosphere 1Department of Chemistry, University of York, Heslington, York, YO10 5DD, UK
02 Aug 2013
2Department of Chemistry and Biochemistry, Old Dominion University, Norfolk, Virginia 23529, USA
Received: 05 Dec 2012 – Published in Atmos. Chem. Phys. Discuss.: 04 Feb 2013Abstract. This work reports the first infrared satellite remote-sensing measurements
of acetonitrile (CH3CN) in the Earth's atmosphere using solar
occultation measurements made by the Atmospheric Chemistry Experiment
Fourier transform spectrometer (ACE-FTS) between 2004 and 2011. The
retrieval scheme uses new quantitative laboratory spectroscopic measurements
of acetonitrile (Harrison and Bernath, 2012). Although individual ACE-FTS
profile measurements are dominated by measurement noise, median profiles in
10° latitude bins show a steady decline in volume mixing ratio
from ~150 ppt (parts per trillion) at 11.5 km to < 40 ppt at 25.5–29.5 km. These new measurements agree well with the scant available air- and
balloon-borne data in the lower stratosphere. An acetonitrile stratospheric
lifetime of 73 ± 20 yr has been determined.
Revised: 21 Jun 2013 – Accepted: 24 Jun 2013 – Published: 02 Aug 2013
Citation: Harrison, J. J. and Bernath, P. F.: ACE-FTS observations of acetonitrile in the lower stratosphere, Atmos. Chem. Phys., 13, 7405-7413, doi:10.5194/acp-13-7405-2013, 2013.