There is an interesting article in NOAA ESRL Fall Newsletter by Linda Joy titled
This article presents yet another example of the diversity of human and natural climate forcings and feedbacks. Excerpts from the article are
Rain clouds within a large cloud field respond to signals from other clouds, much like chirping crickets or flashing fireflies on a summer night, according to a new ESRL-led study. Published in Nature in August,the finding has significant implications for our understanding of climate change.
Graham Feingold (CSD) and his colleagues showed for the first time that interactions between certain types of neighboring clouds can result in synchronized rain patterns within a large cloud system.
The scientists say that their findings point to a significant influence of particulate matter, or aerosols, on the large-scale structure of clouds and, therefore, on climate change. Scientists have long known that aerosols can influence local rain formation and block solar energy from reaching the Earth’s surface—for an overall surface cooling effect.
However, until recently, the scientific community has not considered the self-organization that results from these effects. Computer simulations for this study indicate that high aerosol concentrations favor the formation of large, dense cloud fields with less open space and less rain.
This creates a more reflective cloud pattern and cooling of the surface. Low particulate levels in computer models resulted in rain and the open honeycomb structure with an oscillating pattern. The open honeycomb structure in a large cloud field lets more sunlight reach the surface, and hence results in surface warming.
“Our work also suggests that we should expand our thinking about interactions between aerosols and clouds,” Feingold said. “Integrating our current focus on fundamental physical processes with broader studies on system dynamics could give us a more complete understanding of climate change.”
Climate Science: Roger Pielke Sr. 