Some aspects of multi-timescales issues for the numerical modeling of atmospheric chemistry

Bruno Sportisse and Rafik Djouad

Accepted for the Proceedings Book of the Workshop Atmospheric Modeling, IMA, Minneapolis, March 2000. IMA Volumes in Mathematics and its Applications. Volume 130. Editors: David P. Chock and G.R. Carmichael. Pages 39-61.

We review in this article some issues related to multi-timescales for the numerical modeling of atmospheric chemical kinetics. There is indeed a wide range of characteristic timescales for atmospheric chemistry and the time evolution is characterized by a slow-fast behaviour. We present here some related points: the use of appropriate stiff solvers (numerical point of view), the existence of an underlying reduced model (the counterpart for modeling) and some by-products for other aspects of numerical modeling (e.g. splitting methods and adjoint modeling).