Indian Ocean SST
switch-on experiments
Switch-on experiment
Switch-on experiment
Switch-on experiment
R
K
Switch-on experiment
T (K)
q (g/Kg)
P (mm/day)


==> T
~ dyn
t
p
q.v



~ P ==>
t
p

, T
Switch-on experiment
T (K)
q (g/Kg)
P (mm/day)
Switch-on experiment
Diabatic heating profile in equilibrium state
Switch-on experiment
prc
vq’
(vq)’
v’q
Wave Dynamics
T’>0
M
less CAPE
reduced
Convection
q’<0
Africa
Intensified
convection
q’>0
Indian ocean
Response to CO2 forcing
with fixed SST
At least in the GFDL model, there is comptet
Response to CO2 forcing
with fixed SST
• At least in the AM2, there is a tug war between the direct
radiative effect of CO2 and the surface SST warming.
• In AM2, SST wins; in CAM3, CO2 wins.
• But in both model, the response to 2xCO2 seems to be robust.
Simulated summer (Jul-Aug-Sept) Sahel rainfall by NCAR CCSM3.0 (upper) and GFDL CM2
coupled climate models driven by the estimated observation of solar, greenhouse gas,
aerosol and land use forcing (1870-1999) plus A1B future scenario forcing (2000-1099).
Annual mean response to 2xCO2 and 2K uniform SST warming
2xCO2
+2K
ANN response to 2xCO2 forcing, but
fixed SST
ANN