Summary: Photodissociation of acetone: Atmospheric implications of
temperature-dependent quantum yields
S. R. Arnold and M. P. Chipperfield
Institute for Atmospheric Science, School of Environment, University of Leeds, Leeds, UK
M. A. Blitz, D. E. Heard, and M. J. Pilling
Department of Chemistry, University of Leeds, Leeds, UK
Received 18 November 2003; revised 1 March 2004; accepted 18 March 2004; published 13 April 2004.
[1] We have used a photochemical box model to
investigate the effect of temperature-dependent quantum
yields of acetone on the chemistry in the upper troposphere.
The T-dependent quantum yields produce a photolysis (J)
rate up to factor 3­10 slower than room temperature values.
This reduced J rate significantly reduces the contribution of
acetone to the mid-latitude and tropical UT HOx budgets by
factors of 4 and 2 respectively, when constrained with
location-specific aircraft observations. The calculated
lifetime of acetone in the UT increases from $75 to
$250 days at mid-latitudes and from $10 to $20 days in
the tropics, for the conditions used here. This will
significantly affect studies aimed at balancing the

Source: Arnold, Steve - School of Earth and Environment, University of Leeds

Collections: Environmental Sciences and Ecology