Eastern Pacific surface fluxes observed and simulated by coupled GCMs
description
Transcript of Eastern Pacific surface fluxes observed and simulated by coupled GCMs
Eastern Pacific surface fluxes observedand simulated by coupled GCMs
Simon de Szoeke & Chris Fairall
de Szoeke et al. 2010: Surface Flux Observations on the Southeastern Tropical Pacific Ocean and Attribution of SST Errors in Coupled Ocean–Atmosphere Models, J. Climate.
surface heat budget
0 = –∂/∂t SSTturbulent evaporation and sensible fluxnet radiationocean residual
annual average heat budget
+ +
= 0
“observed” coupled GCM simulations
Ocean residual flux
Colbo and Weller 2007
surface ocean heat budgetOctober
ship-observedheat fluxes20°S, October
surface heat budgetΔS > 40 W m-2
obs.
surface heat budget errors
obs.
solar longwave
surface downwelling radiationW
m-2
longitude
clear
full
S0: Iqbal 1988 R0: Hare 2005
solarlongwave
surface downwelling radiationW
m-2
longitude
solar transmission
clear
cloudyfull
longwave cloud effect
10 minuteaverages
Cloud forcing phase diagrampolarcold dry columnlow sun
tropicalwarm moistcolumn,high sun
Cloud forcing phase diagram
2(R–R
0) >
|S–S
0| +
10
W m
-2
Daily average cloud radiative forcing
xx: solar-weighted cloud fractionred: 2(R–R0) > |S–S0| + 10 W m-2
longwave
solar
models
ship
buoy
ISCCP
model surface cloud forcing
Does insolation explain SST?
no
surface heat budget0 =
–∂/∂t SSTturbulent evaporation and sensible fluxnet radiationocean residual =
Ekman transportgeostrophic transportupwellingeddy flux divergence
damp SST
the end
?