A new finding might finally answer a question that has dogged climatologist for a while: why is there a slight cooling trend, when there should be a significant spike in temperatures, due to global warming.
University of Manchester scientists have shown that natural emissions and organic pollutants that are man made, are both concomitantly responsible for the formation of a brighter cloud, thereby allowing the clouds to deflect the sun's rays, much like the ice in the polar caps do, and in this way actually have an unexpected cooling effect.
Clouds are made of water droplets, condensed onto tiny particles suspended in air. The number and the size of these 'particles' are what control both the size of clouds and their brightness.
The question now is how much of an impact do these new effects have in region with higher pollution.
The researchers have found that tiny particulates and organic material, contain material that are volatile, so that in warmer climates they become vapour. But in the atmosphere, the compounds act in reverse in warmer climates, the molecules reverting to liquid form and becoming larger, thereby 'seeding' the clouds more efficiently.
They also enhance the brightness of the cloud as we have seen, due in part to the higher amount of water the 'seeding' engenders.
The brightness is more visible from above, which is the reason why the clouds are efficient at reflecting the light back onto the atmosphere.
Source: Science Daily 5.6.13
No comments:
Post a Comment