Affiliation: | 1. Hadley Centre, Met Office, Exeter, UK 2. The Abdus Salam International Centre for Theoretical Physics, Earth System Physics Section, Trieste, Italy 3. Centre for Ocean-Land-Atmosphere studies and George Mason University, Fairfax, VA, USA 4. Institute for Atmospheric and Climate Science, ETH, Zurich, Switzerland 5. Centre for Australian Weather and Climate Research, Melbourne, Australia 6. School of Earth Environmental Sciences, Seoul National University, Seoul, South Korea 7. Meteorological Research Institute, Japan Meteorological Agency, Tokyo, Japan 8. Geophysical Fluid Dynamics Laboratory, Princeton, NJ, USA 9. NASA Goddard Space Flight Centre, Greenbelt, MD, USA 10. Voeikov Main Geophysical Observatory, St. Petersburg, Russia 11. Queensland Climate Change Centre of Excellence, Queensland, Australia 12. University of Maryland, Baltimore, MD, USA 13. LASG, Institute of Atmospheric Sciences, Beijing, China
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Abstract: | We use a simple methodology to test whether a set of atmospheric climate models with prescribed radiative forcings and ocean surface conditions can reproduce twentieth century climate variability. Globally, rapid land surface warming since the 1970s is reproduced by some models but others warm too slowly. In the tropics, air-sea coupling allows models to reproduce the Southern Oscillation but its strength varies between models. We find a strong relationship between the Southern Oscillation in global temperature and the rate of global warming, which could in principle be used to identify models with realistic climate sensitivity. This relationship and a weak response to ENSO suggests weak sensitivity to changes in sea surface temperature in some of the models used here. In the tropics, most models reproduce part of the observed Sahel drought. In the extratropics, models do not reproduce the observed increase in the North Atlantic Oscillation in response to forcings, through internal variability, or as a combination of both. |