Climate Model Simulations of Current Climate

• Surface Temperatures
• Annual mean accurate to within about 2^oC
• Problems in high latitudes and areas with large topographic variations
• Underestimate cooling effect of marine stratus along west coasts
• Model average fairly good at getting magnitude of annual cycle
• Precipitation
• Decent qualitative agreement for annual mean
• Fairly large variations between individual models, especially in tropics
• Convection drives tropical precipitation, is poorly represented in models
• Models do somewhat better job with midlatitude storms
• Ocean
• Oceanic heat transports show substantial inter-model spread
• Generally too large in northern midlatitudes
• Too small moving southward from equator
• Wind stress captured reasonably well
• Fairly wide spread in SST estimates, especially in high latitudes
• Sea ice distributions roughly correct
• Overall Model Performance
• Comparisons with earlier models show some improvement
  • Fewer models now use flux corrections
  • Surface air temperature best, precipitation worst
  • Still broad spread between models