Balloon-borne radiometer measurements of Northern Hemisphere mid-latitude stratospheric HNO₃ profiles spanning 12 years

M. Toohey (1) , B. M. Quine (2) , K. Strong (1) , P. F. Bernath (3, 4) , C. D. Boone (4) , A. I. Jonsson (1) , C. T. Mcelroy (5) , K. A. Walker (1, 4) , D. Wunch (1, 6)

1 Department of Physics [Toronto]
2 School of Engineering
3 Department of Chemistry [York, UK]
4 Department of Chemistry [Waterloo]
5 ECCC - Environment and Climate Change Canada
6 CALTECH - California Institute of Technology

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.

Domaines: Océan, Atmosphère

M. Toohey, B. M. Quine, K. Strong, P. F. Bernath, C. D. Boone, et al.. Balloon-borne radiometer measurements of Northern Hemisphere mid-latitude stratospheric HNO₃ profiles spanning 12 years. Atmospheric Chemistry and Physics, 2007, 7 (23), pp.6075-6084. ⟨hal-00296396⟩