On the question of enhanced absorption of solar radiation by clouds

Some recent papers have claimed that clouds cause the atmosphere to absorb significantly more solar radiation than current understanding would predict. In this paper aircraft measurements of the broad-band and narrow-band radiation fields in and around different cloud types are presented. These measurements have been made over a number of years by the C-130 aircraft of the UK Meteorological Office, in several different locations around the globe. our observations show no evidence of this 'enhanced' cloud absorption, and they can be explained, both qualitatively and quantitatively, by currently accepted theory. The suggestion that such enhanced absorption is due to one particular mechanism, that of increased condensed-phase water absorption in the near-infrared, is examined. This hypothesis is rejected as being completely at variance with the observations.