Current interpretations of these data suggest that theoretical models of the Earth climate system may be missing a global-mean absorption of radiation by clouds of between 25 and 40 watts per square meter. Past interpretations may have falsely represented the absorption as occurring at the surface when, in fact, a substantial redistribution of energy from the surface into the atmosphere may actually be occurring. According to Jeff Kiehl at NCAR, the magnitude of the phenomenon is three times that of doubling of carbon dioxide, with the principal influence being exerted on the hydrologic cycle.
According to meeting participants, recent predictive abilities have been limited by contemporary top-of-the-atmosphere-to-surface radiative transfer algorithms that are used to interpret satellite measurements. Because these algorithms do not account for either the enhanced (anomalous) cloud shortwave absorption or broken-cloud effects (that serve to reduce the atmospheric shortwave absorption), the algorithms need to be questioned. A value-added experiment is being designed for the ARM Program's Southern Great Plains (Cloud and Radiation Testbed) site to quantify the anomalous absorption phenomenon. The experiment will be conducted as an intensive observation period during the spring or summer of 1995.
Two papers that describe the measurements and implications of anomalous cloud absorption, entitled "Absorption of Solar Radiation by Clouds: Observations Versus Models" by R.D. Cess et al. and "Warm Pool Heat Budget and Shortwave Cloud Forcing: A Missing Physics?" by V. Ramanathan et al., have recently appeared in Science magazine.