A Comparative Study of the Construction of Global Climate Models
Steve Easterbrook, University of Toronto
(http://www.cs.toronto.edu/~sme/)
Abstract:
In the literature, comparisons between climate models tend to focus on how well each model captures various physical processes, and how skillful they are in reproducing the climatology of observational> datasets. In this talk, we present a different type of comparison, based on an analysis of the software architecture of global climate models. As with the architecture of a historic building, the architecture of a typical climate model includes a mix of older and newer elements, and evidence of re-purposing as new generations of scientists have adapted the model to new uses. An analysis of the development history of each model shows a mix of ‘essence’ and ‘accident’. The essence include explicit design decisions that all climate modellers face (e.g. the choice of grids, selection of numerical methods for the dynamical core, use of particular coupling technologies, etc), while the accidental aspects represent constraints that are beyond the immediate control of a model’s designers (e.g. available funding and expertise, the demands of different user groups, the rhythms imposed by collaborations between different research groups, etc). The talk will draw on a observations from case studies of four major models from four different countries: the UK Met Office Hadley Centre (UKMO); the US National Centre for Atmospheric Research (NCAR); the German Max-Planck Institute for Meteorology (MPI-M); and the French Institute Pierre Simon Laplace (IPSL). We will use differences in the architecture of these four models to illustrate some of the different organizational constraints faced by climate research labs. The result of the analysis suggests that there may be much more structural diversity among the current generation of earth system models than is revealed in recent comparisons of their climatology.
Bio:
Steve Easterbrook is a professor of computer science at the University of Toronto. He received his Ph.D. (1991) in Computing from Imperial College in London (UK), and was a lecturer at the School of Cognitive and Computing Science, University of Sussex from 1990 to 1995. In 1995 he moved to the US to lead the research team at NASA´s Independent Verification and Validation (IV&V) Facility in West Virginia, where he investigated software verification on the Space Shuttle Flight Software, the International Space Station, the Earth Observation System, and several planetary probes. He moved to the University of Toronto in 1999. His research interests range from modelling and analysis of complex software software systems to the socio-cognitive aspects of team interaction. In the last five years he has focussed his research on the software and communication tools used for understanding and explaining climate change. He has served on the program committees for many conferences and workshops in Requirements Engineering and Software Engineering, and was general chair for RE’01 and program chair for ASE’06. In the summer of 2008, he was a visiting scientist at the UK Met Office Hadley Centre, and in 2010 a visiting scientist at NCAR, MPI-M and IPSL.