Island and ship trail clouds: the rosetta stone of clouds, pollution, and climate

摘要

Cloud/Climate Feedback is a combination of words known to be important butextremely difficult to quantify or even assign a direction. A 4 % increase in boundary layer clouds would cool the earth as much as a doubling of CO(sub 2) would warm it (Randall et al, 1984). Studies have shown that warmer sea surface temperatures are associated with fewer clouds (Oreopoulos and Davies, 1992). We do not know how much of this effect is due to direct solar warming of surface water in the absence of clouds. We also know there are more eastern ocean marine boundary layer clouds in summer than winter. Do warmer sea surface temperatures or more summer-like conditions best represent global warming. Twomey, 1974 has proposed that increasing aerosol pollution would lead to brighter clouds (indirect aerosol effect). This relationship does have determined sign (i.e. cooling) but is very difficult to quantify. Cloud trails from ships and islands hold the potential of addressing Cloud/Climate Feedback by observing atmospheric response to large perturbations in turbulence and aerosol. However, before cloud trails can be used as a Rosetta Stone connecting pollution and climate, much more