EDP Sciences
Free access
Volume 398, Number 1, January IV 2003
Page(s) 335 - 344
Section The Sun
DOI http://dx.doi.org/10.1051/0004-6361:20021659

A&A 398, 335-344 (2003)
DOI: 10.1051/0004-6361:20021659

Effect of chemical kinetic uncertainties on photochemical modeling results: Application to Saturn's atmosphere

M. Dobrijevic, J. L. Ollivier, F. Billebaud, J. Brillet and J. P. Parisot

Observatoire de Bordeaux, BP 89, 32270 Floirac, France
(Received 14 February 2002 / Accepted 21 October 2002)

Reaction rates included in photochemical models of planetary atmospheres carry with them a level of imprecision. This imprecision leads to an uncertainty in computed mole fractions of chemical species. We present estimations of the uncertainties on mole fraction profiles, obtained using a 1-D photochemical model applied to the study of hydrocarbon compounds in Saturn's atmosphere. We calculate the uncertainties as a function of altitude for each compound and derive the mean value and the standard deviation of the mole fraction. We show that the uncertainties on the mole fraction of hydrocarbons determined from a photochemical model are very significant. Ethane and acetylene, the most abundant hydrocarbons in Saturn's atmosphere after methane, are affected by an uncertainty factor of about 1.5, and the mole fraction of complex hydrocarbons, which are the products of a more complex chemistry, are affected by a large uncertainty factor which can reach 24. We discuss the implications for the determination of the eddy diffusion coefficient. In particular, we show that uncertainties on the calculated mole fractions produce a large uncertainty on the eddy diffusion coefficient profile in the lower atmosphere.

Key words: planets and satellites: individual: Saturn -- methods: numerical

Offprint request: M. Dobrijevic, michel@observ.u-bordeaux.fr

© ESO 2003

What is OpenURL?

The OpenURL standard is a protocol for transmission of metadata describing the resource that you wish to access.

An OpenURL link contains article metadata and directs it to the OpenURL server of your choice. The OpenURL server can provide access to the resource and also offer complementary services (specific search engine, export of references...). The OpenURL link can be generated by different means.

  • If your librarian has set up your subscription with an OpenURL resolver, OpenURL links appear automatically on the abstract pages.
  • You can define your own OpenURL resolver with your EDPS Account.
    In this case your choice will be given priority over that of your library.
  • You can use an add-on for your browser (Firefox or I.E.) to display OpenURL links on a page (see http://www.openly.com/openurlref/). You should disable this module if you wish to use the OpenURL server that you or your library have defined.