cc: Mike Hulme date: Thu, 22 Jan 1998 19:49:21 -0700 (MST) from: Tom Wigley subject: COSMIC to: Philip Newton Dear Philip, Michael Schlesinger mentioned to me that you had expressed an interest in his software package "COSMIC". You may not realize that my colleagues and I in CRU (notably Mike Hulme, Mike Salmon, Sarah Raper and Ogla Brown) developed similar user-friendly software some years ago. It comes in two integrated components, MAGICC and SCENGEN. MAGICC does the global-mean calculations that are used to drive the regional climate-change pattern algorithms in SCENGEN. It is widely used; and has been integrated into a more complex Integrated Assessment package by Jae Edmonds, Hugh Pitcher and others at Battelle. The principle used by our software is the same as used by Schlesinger in COSMIC. The method was invented by Ben Santer and me almost 10 years ago. MAGICC employs the same models that I used in doing the latest IPCC global-mean temperature and sea level projections. Michael uses similar models, but they are not "the" IPCC models. SCENGEN employs a large database of GCM results, overlapping the database that Michael uses. SCENGEN also includes regionally-specific SO2 emissions scenarios, using a compositing method that I invented some years ago. Michael uses the same method; but I don't think he has implemented this part of his code yet. SCENGEN can give global maps of climate change, or higher-resolution maps for a number of selected regions. SCENGEN uses a better observed climate database than COSMIC, drawing on 20 years of work in this area in CRU. I believe SCENGEN also gives output for a wider range of climate variables than COSMIC. In my view, COSMIC simply re-invents the wheel that we developed some time ago. Michael tends to be rather cavalier in giving credit to others. He has known about MAGICC/SCENGEN for some time; but I doubt that he has ever bothered to look at the software. If you want to know more, contact Mike Hulme (details below). The latest version of MAGICC/SCENGEN was developed largely under his direction. It is available on a CD-ROM to run under Windows. It is easy, educational and fun to use. Cheers, Tom cc: Mike Hulme Climatic Research Unit University of East Anglia Norwich NR4 7TJ, United Kingdom Tel: 1603-593162 Fax: 1603-507784 Email: m.hulme@uea.ac.uk ********************************************************** *Tom M.L. Wigley * *Senior Scientist * *National Center for Atmospheric Research * *P.O. Box 3000 * *Boulder, CO 80307-3000 * *USA * *Phone: 303-497-2690 * *Fax: 303-497-2699 * *E-mail: wigley@ucar.edu * **********************************************************