'Rain-making' bacteria found around the world

Some microbes are frequent flyers in clouds

The same bacteria that cause frost damage on plants can help clouds to produce rain and snow. Studies on freshly fallen snow suggest that ‘bio-precipitation’ might be much more common than was suspected.

Before a cloud can produce rain or snow, rain drops or ice particles must form. This requires the presence of aerosols: tiny particles that serve as the nuclei for condensation. Most such particles are of mineral origin, but airborne microbes — bacteria, fungi or tiny algae — can do the job just as well. Unlike mineral aerosols, living organisms can catalyse ice formation even at temperatures close to 0 ºC.

The effect of the biological ‘ice nucleators’ on precipitation has been a mystery, not least because no one has yet been able to detect them in clouds.

Further more see on article by Quirin Schiermeier here.