1. Program for Climate Model Diagnosis and Intercomparison, Lawrence Livermore National Laboratory, Livermore, CA 94550, USA.
2. National Center for Atmospheric Research, Boulder, CO 80303, USA.
3. Remote Sensing Systems, Santa Rosa, CA 95401, USA.
4. National Oceanic and Atmospheric Administration (NOAA)/Air Resources Laboratory, Silver Spring, MD 20910, USA.
5. Hadley Centre for Climate Prediction and Research, UK Met Office, Exeter, EX1 3PB, UK.