What controls the total heat transport in CMIP3 models

Aaron Donohoe

AGU 2010 – 12/12/2010

Heat Transport Spread In Climate Models

Observations

Peak Heat Transport Histograms

Understanding heat transport

5.7 PW

Heat Transport = -

8.1 PW 2.4 PW

ASR* OLR*

Model heat transport spread in terms of OLR* and ASR*

Understanding ASR*

Heat transport and planetary albedo

What determines the amount of solar radiation reflected at the top of the atmosphere?

Earth’s Surface

Atmosphere

Solar Incident

Reflected by Atmosphere

Reflected by Surface

Zonal Mean Planetary albedo partition (observations are dark

models dotted and light).

Heat transport and cloud reflection

Conclusions

• The model spread in heat transport is due to gradients in net solar radiation (ASR*)

• Gradients in net solar radiation are due to gradients in Planetary Albedo

• Gradients in Planetary Albedo are due to the simulated cloud distribution

• Cloud’s determine Heat Transport • We explained a dynamic quantity without

invoking dynamics- do dynamics play an active or passive role in determining the radiative fields?