MCM/AtChem Online Tutorial

By J. C. Young, A. R. Rickard, K. Borońska and M. J. Pilling

With thanks to C. Martin and R. Sommariva


The Master Chemical Mechanism (MCM) is based on the original protocol devised by Jenkin et al. in 1997, which has subsequently been updated and improved (Saunders et al., 2003; Jenkin et al., 2003). The MCM can be easily navigated and downloaded (in a variety of formats, either in full or subsets of the mechanism) from the MCM website.

AtChem Online is a modelling tool designed for running simulations of the Master Chemical Mechanism using just your web browser, no installation is required. The user needs only to supply two files: one with the chemical reactions (extracted directly from the MCM) and one with the initial concentrations, changing the other parameters if necessary and press "Submit". A link to a zip file with the results should then be available to dowload.

Currently there is one login for everyone. This will be changed in the future and users will need to register to receive an individual login. Until then, remember that everyone can access your data. Please report any issues or request the password by contacting Andrew Rickard, CC Killian Murphy.

The following tutorial contains a variety of exercises designed to demonstrate all the features of AtChem Online by using the Master Chemical Mechanism in the context of environmental chamber studies. The tutorial consists of:

  1. Introduction to the use of AtChem Online.
  2. Using AtChem with the MCM.
  3. Importance of chamber specific auxiliary mechanisms.
  4. Chamber modelling of aromatic system using MCMv3.1.
  5. Simulation of a PSI 1,3,5-trimethylbenzene Experiment
  6. References
  7. Answers and discussion

To complete this tutorial you will only need a web browser, a program such as word pad or notepad to view and edit input files and a spreadsheet package such as MS Excel for processing the model output

Most of the exercises are based on real data from chamber studies carried out at out various EUROCHAMP2 facilities. For more information please visit the main MCM website. For questions on this tutorial and the MCM in general please contact Andrew Rickard.