Title: Evaluated kinetic data for atmospheric
Chairman: R.A. Cox
Members: M. Amman, R.
Atkinson, J.N. Crowley,
R.F. Hampson, R.G.
Hynes, M.E. Jenkin,
M. J. Rossi, and J.
Troe, and T.J. Wallington
Completion Date: 2007 - project completed
Remarks: see project
2007-001-2-100 for continuation
Continuation and expension of 141/3/89
The primary objective of this project is to enhance the accessibility
and availability of the evaluated kinetic database, which has been
assembled by the IUPAC Subcommittee for Gas Kinetic Data evaluation
for Atmospheric Chemistry, by placing the material on an interactive
site on the www. A second objective is to develop and implement a
scheme for updating the material on the website.
The IUPAC Subcommittee (formally the CODATA Task Group on Chemical
Kinetics) was originally tasked to produce an evaluation of the existing
chemical kinetics data in 1977, in response to the need to provide
an internationally judged data set for modelling the depletion of
atmospheric ozone due to man made pollutants. Since that time the
Subcommittee has continued to expand and update the evaluations to
aid modelling of a wide range of issues involving Atmospheric Chemistry.
The evaluations have been published in a series of nine peer reviewed
articles in J. Phys. Chem. Ref. Data. These articles contain
two elements: Firstly a summary table which contains a list of recommended
rate parameters giving the best available values for rate coefficients
for use in models representing atmospheric chemistry explicitly as
a system of elementary chemical reactions: Secondly each reaction
is discussed in a separate data sheet, in which the key experimental
data are summarised and the basis of the recommendation together with
its uncertainty is given. These data sheets provide details which
are of interest to atmospheric modellers and experimental scientists
conducting investigations of kinetics and mechanisms of atmospheric
reactions, and chemical kinetics generally.
In order to further publicize the accessibility of this web-based
material to the scientific community, the evaluation is also being
published as a series of journal articles in Atmospheric Chemistry
In 1998 the IUPAC Subcommittee created a website at the Centre for
Atmospheric Science in the Department of Chemistry, University of
Cambridge, UK, (http://www.iupac-kinetic.ch.cam.ac.uk).
This site has attracted very significant interest since its creation,
and has now been expanded, and a mirror site has been created at the
IUPAC HQ website in N. Carolina, US. Currently there are approximately
2000 connections to the website per week and over 300 subscriptions
to the web mailing list for announcements.
The main purpose of the ongoing IUPAC project is to
extend the content of the website to include the remaining datasheets
for the 600 gas phase reactions, the photochemical reactions (absorption
cross sections, quantum yields), and heterogeneous reactions (kinetic
uptake coefficients for atmospheric gases on a range of surfaces),
for which the data have been evaluated since the first publication
by the Group in 1980. In addition to expansion, the website is continually
being modified to give improved access, including a simple search
facility and implemented hyperlinks between the summary table and
the data sheets.
The database covers over 600 reactions relevant to the chemistry of
the stratosphere and the troposphere. The data sheets are grouped
in a series of categories which include:
In the future the efforts of laboratory kineticists
will continue to provide new data in response to new scientific and
societal issues in the field of Atmospheric Chemistry. The IUPAC Group
is seeking a more effective way of updating and extending the portfolio
of recommended rate coefficients, which will be necessary to maintain
an effective and ongoing communication between laboratory scientists
and atmospheric modellers.
The establishment of web-based material allows for
the first time the opportunity of near continuous update of the evaluation.
The development and implementation of protocols for the updating of
the evaluation, both web-based and archived hard copy will also be
listing (including latest supplements)
For an overview, see Chem Int. (Tools of the
Trade series) Vol. 29 No. 1, Jan-Feb 2007 >
> Dec 2007 report update (pdf
file - 2.6MB)
Project completed > see project
2007-001-2-100 for continuation
Last Update: 18 December 2007
<project announcement published