1. Brief update on the halocarbon experiment
Øivind Hodnebrog, Keith P. Shine, Gunnar Myhre, Bjørn H. Samset
+ PDRMIP
PDRMIP, London
11-12 May, 2017

2. Simulations with increased CFC concentrations
RF (W m-2), LBL code
RF (W m-2), fixed SST
TOA
SFC
ATM
CFC-11
0.94
0.49
0.45
CFC-12
1.4
0.74
0.65
Model
TOA
SFC
ATM
CFC-11
CAM4
1.2
1.1
0.12
CFC-12
1.5
1.3
0.20
CAM5
0.45
NorESM
1.4
0.19

3. Rapid adjustments Specific humidity Temperature
Radiative kernels show that
Increases in WV in lower troposphere reduce atmospheric absorption
Increases (decreases) in stratospheric temperature reduce (strengthen) atmospheric absorption

4. Rapid adjustments
Specific humidity
Temperature

5. Rapid adjustments
Specific humidity
Temperature

6. Rapid adjustments
Specific humidity
Temperature

7. Rapid adjustments
Specific humidity
Temperature

8. Zonal mean temperature (K)
CFC-12 experiment

9. Halocarbon experiments
CFC-12: From present-day mixing ratio to 5 ppb (we used 535 ppt for present-day)
If you have a lot of computer resources we suggest the additional two runs
CFC-11: From present-day mixing ratio to 5 ppb (we used ppt for present-day (this accounts also for other halocarbon gases))
N2O: From present-day mixing ratio to 1 ppm (we used 316 ppb for present-day)