Mechanism reduction techniques applied to tropospheric chemistry

Mechanism reduction techniques previously developed to simplify complex combustion mechanisms with minimal loss of accuracy have been applied to the tropospheric chemical mechanism CBM-EX. The species and reactions necessary to reproduce ozone concentrations within 10% of those predicted by CBM-EX were found by applying the techniques over three concentration scenarios selected to represent the range of conditions over which CBM-EX was derived. The resulting reduced mechanism, CBM-LEEDS contains 59 reactions and 23 species compared with 205 reactions and 90 species in CBM-EX. Comparisons were also made with a published condensed form of CBM-EX, CBM-IV (81 reactions and 33 species) for a number of simulations typical of environmental chamber and Lagrangian trajectory studies of tropospheric chemistry.