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


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. Application of detailed 3-dimensional atmospheric chemistry codes requires substantial computer time. This work will be developed on the new Fujitsu VPP300.


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 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 in collaboration with Glenn Carver and John Pyle at the Department of Chemistry, Cambridge, UK.

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 with simplified chemistry at the new higher resolution per model year. A fully vectorized Lagrangian trajectory code has been developed. We plan to employ the vectorised atmospheric chemsitry code (ASAD) developed at Cambridge University in further studies using more detailed chemistry code.

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 III, Ecological Modelling, (1995), in press.