Auxiliary material for Paper 2006GL026015

On the stratospheric chemistry of hydrogen cyanide

Armin Kleinboehl, Geoffrey C. Toon, Bhaswar Sen, and Jean-Francois L. Blavier 
Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California, USA

Debra K. Weisenstein 
Atmospheric and Environmental Research, Inc., Lexington, Massachusetts, USA

Rafal S. Strekowski
School of Earth and Atmospheric Science, Georgia Institute of Technology, Atlanta, Georgia, USA

J. Michael Nicovich 
School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, Georgia, USA
Also at School of Earth and Atmospheric Science, Georgia Institute of Technology, Atlanta, Georgia, USA

Paul H. Wine
School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, Georgia, USA

Paul O. Wennberg 
California Institute of Technology, Pasadena, California, USA

Kleinböhl, A., G. C. Toon, B. Sen, J.-F. L. Blavier, D. K. Weisenstein, R. S. Strekowski, J. M. Nicovich, P. H. Wine, and P. O. Wennberg (2006), On the stratospheric chemistry of hydrogen cyanide, Geophys. Res. Lett., 33 (11), L11806, doi:10.1029/2006GL026015.

Introduction

Included here are supplemental files that provide additional information
on the frequency microwindows used for the HCN retrieval from the
solar occultation measurements, the correlation of HCN with the stratospheric
tracer N2O, and the lifetime of HCN against oxidation based on the different
sets of rate coefficients. The supplement consists of one table and two figures.

1. 2006GL026015-ts01.txt
Frequency windows used for the HCN retrieval. The abundances
of the main interfering gases were adjusted together with the HCN abundance
during the fitting process.

2. 2006GL026015-fs01.eps
(left) Retrieved vertical profiles of HCN from 10 balloon flights
between 1994 and 2004 vs. N2O, measured simultaneously by the MkIV instrument.
The black line is an average of all measurements created by averaging the
HCN VMRs in bins of 30 ppb N2O with the gray shaded area giving the standard
deviation. (middle) MkIV average vs. N2O compared to model runs using HCN
reaction rates from Sander et al. [2003] and Cicerone and Zellner [1983].
(right) MkIV average vs. N2O compared to model runs using the new HCN chemistry
(Strekowski et al., 2001). For a detailed description of the individual model
runs the reader is referred to Table 1 in the main part of the paper.

3. 2006GL026015-fs02.eps
Local lifetime of HCN in years for the month of September
considering the destruction by OH and O(1D) based on the rate coefficients
from (left) Sander et al. [2003] and Cicerone and Zellner [1983], respectively, and (right) from Strekowski [2001].

References

Cicerone, R. J., and R. Zellner (1983), The atmospheric chemistry of hydrogen cyanide
  (HCN), J. Geophys. Res., 88, 10,689-10,696.

Sander, S. P., et al. (2003), Chemical kinetics and photochemical data for use in
  atmospheric studies: Evaluation number 14, Tech. Rep. Pub. 02-25,
  Jet Propul. Lab., Pasadena, Calif.

Strekowski, R. S., J. M. Nicovich, and P. H. Wine (2000),
  Quenching of O1D2 by Cl2CO, Chem. Phys.
  Lett., 330, 354-360.