On the Surface Temperature Sensitivity of the Reflected Shortwave, Outgoing Longwave, and Net Incident Radiation

Hartmut H. Aumann, Alexander Ruzmaikin, Ali Behrangi
2012 Journal of Climate  
The global-mean top-of-atmosphere incident solar radiation (ISR) minus the outgoing longwave radiation (OLR) and the reflected shortwave radiation (RSW) is the net incident radiation (NET). This study analyzes the global-mean NET sensitivity to a change in the global-mean surface temperature by applying the interannual anomaly correlation technique to 9 yr of Atmospheric Infrared Sounder (AIRS) global measurements of RSW and OLR under cloudy and clear conditions. The study finds the observed
more » ... nds the observed sensitivity of NET that includes the effects of clouds to be 21.5 6 0.25 (1s) W m 22 K 21 and the clear NET sensitivity to be 22.0 6 0.2 (1s) W m 22 K 21 , consistent with previous work using Earth Radiation Budget Experiment and Clouds and the Earth's Radiant Energy System data. The cloud effect, 10.5 6 0.2 (1s) W m 22 K 21 , is a positive component of the NET sensitivity. The similarity of the NET sensitivities derived from forced and unforced models invites a comparison between the observed sensitivities and the effective sensitivities calculated for the Fourth Assessment Report models, although this requires some caution: The effective model sensitivities with clouds range from 20.88 to 21.64 W m 22 K 21 , the clear NET sensitivity in the models ranges from 22.32 to 21.73 W m 22 K 21 , and the cloud forcing sensitivities range from 10.14 to 11.18 W m 22 K 21 . The effective NET and clear NET sensitivities derived from the models are statistically consistent with those derived from the AIRS data, considering the observational and model derivation uncertainties.
doi:10.1175/jcli-d-11-00607.1 fatcat:7fi54jqybzckve5k34grwurali