Alternative Ocean and Ice Initial Conditions for the CCSM

Can simple initial conditions be used?How does the spin-up change?

Initial Conditions

Ocean

Ice

CCSM

OZM/IM

OZM/I0

January-Mean Levitus/Poles

Mysterious

Zonal- and Time-Mean Levitus/Poles

Mysterious

Zonal- and Time-Mean Levitus/Poles

Zero

“…. We now try to address why the CSM1 has achieved this success. We believe there is a two-part answer: the first is the state-of-the-art component models, and the second is the spin-up procedure used. ….” Boville and Gent (1998)

CSM1

1000y

50y

150y

NH Ice Volume, Snow Volume, and Ice Area

OZM/IM OZM/IMCCSM

OZM/I0

Sea Surface Temperature

OZM/IM - CCSM OZM/IM – OZM/I0

CCSMOZM/IM

Arctic Sea Surface Salinity

OZM/IM - CCSM OZM/IM – OZM/I0

CCSMCCSM

OZM/IM

Sea Surface Height

OZM/IM - CCSM OZM/IM – OZM/I0

OZM/IM

Ice Volume, Snow Volume, and Ice Area

OZM/I0 CCSM

NH SH

SH Ice Area SH Ice Thickness

OZM/I0 OZM/I0CCSM

CCSM

OZM/I0 - CCSM OZM/I0 - CCSM

Global-mean Potential Temp

ACC Transport

Ocean Time Series

OZM/I0CCSM

OZM/I0 - CCSM OZM/I0 - CCSM

CCSM OZM/I0

Sea Surface Temperature

CCSM OZM/I0

Salinity at 100m

Barotropic StreamfunctionCCSM OZM/I0

OZM/I0 - CCSM

CONCLUSIONS

• Simple initial conditions can be used

• Ice model spin-up is similar

• Ocean has to go through its time scales