Principal Investigator John A Taylor Project s57

Centre for Resource and Environmental Studies Machine VP

Co-Investigators David Hansen, Pat Zimmerman and David Erickson

Centre for Resource and Environmental Studies and

National Center for Atmospheric Research, USA

Tropospheric Chemistry of Ozone and Carbon Monoxide

Since the industrial revolution humankind has been steadily modifying the chemical composition of the atmosphere. This has lead to concerns regarding the stability of the stratospheric ozone layer and the potential for warming of the atmosphere due to increasing levels of greenhouse gases. Another major concern is that the oxidative capacity of the troposphere may be changing. Oxidation of tropospheric gases occur primarily through the action of hydroxyl radicals with concentrations of NOx, CO and CH4 significantly affecting the concentration of these hydroxyl radicals. The objective of this project is to continue development of an existing tropospheric chemistry code running on the VP2200 and perform initial simulations with this code to investigate tropospheric ozone and carbon monoxide concentrations.

What are the basic questions addressed?

What are the consequences of human modification of the chemical composition of the atmosphere?

What are the results to date and the future of the work?

A study of the sources and sinks of atmospheric carbon monoxide has been completed. Future activities include developing a more comprehensive model of tropospheric chemistry.

What computational techniques are used and why is a supercomputer required?

Three-dimensional computations of high resolution atmospheric transport and chemistry are extremely intensive. The models demand large amounts of memory and generate huge amounts of output. Model runs on the VP2200 require approximately 10 minutes of CPU time at the new higher resolution per model year. A fully vectorized Lagrangian trajectory code has been developed.

Publications

A 3-D modelling study of the sources and sinks of atmospheric carbon monoxide, J A Taylor, P R Zimmerman and D J Erickson, Ecological Modelling, III, (1995), in press.