Electronic Data Submission for Paper 2003GL018430

Trajectory studies of large HNO3-containing PSC particles in the Arctic:
Evidence for the role of NAT

K. A. McKinney
Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA
Now at Department of Chemistry, Amherst College, Amherst, MA

P. O. Wennberg
Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA

S. Dhaniyala
Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA
Now at Department of Mechanical and Aeronautical Engineering, Clarkson University, Potsdam, NY

D. W. Fahey, M. J. Northway
NOAA Aeronomy Laboratory, Boulder, CO

K. F. Künzi, A. Kleinböhl, M. Sinnhuber, H. Küllmann, H. Bremer
Institute of Environmental Physics, University of Bremen, Bremen, Germany

M. J. Mahoney
Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA

T. P. Bui
NASA Ames Research Center, Moffett Field, CA


Geophys. Res. Lett., vol. 31, doi:10.1029/2003GL018430, 2004.


Introduction
This data supplement consists of a figure showing vertical profiles of HNO3 measured by the ASUR instrument
from the NASA DC-8 during SOLVE (see main text for mission details.) These HNO3 profiles were used in this
paper to calculate nitric acid hydrate particle growth and evaporation rates.

1. 2003GL018430-F04.gif Vortex averaged nitric acid mixing ratio vertical profiles from the ASUR instrument
[von Koenig et al., 2000] are shown. These were obtained using the Nash [1996] criterion for the vortex
edge, for the December (blue), January (green), and March (cyan) campaigns. Also shown is a mean January
profile that was obtained from measurements at positions inside the vortex without PSC coverage (red).
Error bars represent 1-sigma HNO3 volume mixing ratio standard deviations. Condensation and evaporation of
PSCs probably contributed to the variability in the gas-phase HNO3 profile in December 1999 and January 2000.
At temperatures below the PSC threshold, nitric acid is significantly sequestered in the condensed phase,
and thus would not be observed by ASUR [von Koenig et al., 2002]. The ASUR profiles at these times are,
therefore, likely an underestimate of the total available nitric acid. On the other hand, due to the altitude
resolution of the ASUR instrument [Kleinboehl et al., 2002], the ASUR measurements could overestimate the
available HNO3 in narrow altitude layers due to averaging.

Reference (see main paper for other references)
von Koenig, M., et al., Using gas-phase nitric acid as an indicator of PSC composition, J. Geophys. Res.,
107, 10.1029/2001JD001041, 2002.