KIM : A Chemical Kinetics Model of the OH-initiated Oxidation of DMS in Air : a Monte Carlo Analysis of the Latitude Effect
KIM is embedded into a Monte Carlo stochastic driver which allows prediction of uncertainties and model sensitivities to be investigated. The KIM model results from the selection of a set of reactions describing the OH-initiated oxidation kinetics of DMS. The stochastic part of the exercise involved the conversion of the estimated present level of uncertainty of the system into uncertainty ranges and distributions for the relevant system parameters such as activation energies, kinetic constants, ambient concentrations of trace gases and temperature dependent kinetics parameters. The emphasis is on the temperature/latitude dependence of the quantities of interest, namely the total concentrations of both methane sulphonic acid (MSA) to non sea salt sulphates (NSSS), the ratio MSA/NSSS and the total concentration of peroxynitrates. For the latitude dependency study the model was coupled offline with a general circulation model (MOGUNTIA) in order to generate the latitude dependent variables (temperature, trace gases concentration). The results of the present investigation seem to agree with a recent assessment of the latitude dependency of the MSA/NSSS ration, although the chemical model adopted in that study differ appreciably from the present one. In both cases the ratio increases poleward, as confirmed by field data. The model also seems to indicate a decrease of the total peroxynitrates concentrations at high latitudes.
Bibliographic Reference: EUR 16045 EN (1994) 50pp., FS
Availability: Available from the Public Relations and Publications Unit, JRC Ispra, I-21020 Ispra (IT)
Record Number: 199411688 / Last updated on: 1995-03-21
Original language: en
Available languages: en