Balloon-borne radiometer measurements of Northern Hemisphere mid-latitude stratospheric HNO3 profiles spanning 12 years M. Toohey1, B. M. Quine2, K. Strong1, P. F. Bernath3,4, C. D. Boone4, A. I. Jonsson1, C. T. McElroy6, K. A. Walker1,4, and D. Wunch1,5 1Department of Physics, University of Toronto, Toronto, ON, M5S 1A7, Canada 2School of Engineering, York University, Toronto, ON, M3J 1P3, Canada 3Department of Chemistry, University of York, Heslington, York, YO10 5DD, UK 4Department of Chemistry, Waterloo University, Waterloo, ON, N2L 3G1, Canada 5California Institute of Technology, Pasadena, CA, 91125, USA 6Environment Canada, Downsview, ON, M3H 5T4, Canada
Abstract. Low-resolution atmospheric thermal emission spectra collected by
balloon-borne radiometers over the time span of 1990–2002 are used
to retrieve vertical profiles of HNO3, CFC-11 and CFC-12
volume mixing ratios between approximately 10 and 35 km altitude.
All of the data analyzed have been collected from launches from a
Northern Hemisphere mid-latitude site, during late summer, when
stratospheric dynamic variability is at a minimum. The retrieval
technique incorporates detailed forward modeling of the instrument
and the radiative properties of the atmosphere, and obtains a best
fit between modeled and measured spectra through a combination of
onion-peeling and optimization steps. The retrieved HNO3
profiles are consistent over the 12-year period, and are consistent
with recent measurements by the Atmospheric Chemistry
Experiment-Fourier transform spectrometer satellite instrument. We
therefore find no evidence of long-term changes in the HNO3
summer mid-latitude profile, although the uncertainty of our
measurements precludes a conclusive trend analysis.
Citation: Toohey, M., Quine, B. M., Strong, K., Bernath, P. F., Boone, C. D., Jonsson, A. I., McElroy, C. T., Walker, K. A., and Wunch, D.: Balloon-borne radiometer measurements of Northern Hemisphere mid-latitude stratospheric HNO3 profiles spanning 12 years, Atmos. Chem. Phys., 7, 6075-6084, doi:10.5194/acp-7-6075-2007, 2007.