Abrupt4xCO2 runs

[mfwehner@lbl_gov]

I have plotted the annual global mean surface air temperatures from realization r1i1p1 and r2i1p1 from the abrupt 4xCO2 runs. They are very different. See the attached figure.or this link:https://drive.google.com/file/d/0B_HYE1w2UuTFRldCcVVpOFFIZVE/view?usp=sharing The x-axis is the # of years since the beginning of the file. You will notice that r2i1p1 saturates much more rapidly than does r1i1p1. What is the difference between these two realizations? ThanksMichael

 

[strandwg]

'r1i1p1' is the usual abrupt 4XCO2 case; 'r2i1p1' was run to have the special COSP output for the CFMIP. However, looking at 'co2vmr' from both runs, 'r1i1p1' has 1138.8 ppm (4 X 284.7 ppm); 'r2i1p1' has 1420 ppm (4 X 355 ppm). I don't why 'r2i1p1' was run with 4x "present-day" CO2. The above does explain why r2i1p1 "saturates" more rapidly, however.