From the Daily Mail:
People in drought-stricken countries could one day create rain clouds on demand thanks to laser technology. Physicists have discovered that firing short laser bursts into the air can trigger the formation of water droplets. The breakthrough technique could help stimulate rainfall in the future.
Scientist Jerome Kasparian and his team from the University of Geneva wanted to find a more environmentally friendly alternative to cloud seeding. This 50-year-old process attempts to artificially induce showers. A red laser pulse ionises the air and triggers the condensation of water droplets to create a cloud, which is illuminated by a green laser
Rockets carrying silver iodide particles are scattered in the sky. The particles act as ‘condensation nuclei’ around which water drops can form. Dr Kasparian said cloud seeding is not an efficient method despite decades of development. He added: ‘There are also worries about how safe adding silver iodide particles into the air is for the environment.’
The researchers realised laser technology could be used to create an alternative technique. They found firing an energy beam through an atmospheric cloud chamber created a channel of ionised nitrogen and oxygen molecules. These acted as condensation anchors in much the same way as silver iodide molecules.
The water drops along the damp channel nearly doubled in size from 50micrometres to 80 micrometres as they fused to the ions…
[continues in the Daily Mail]