‘Rain making’ bacteria present in atmosphere, snow

February 29th, 2008 - 4:02 pm ICT by admin  

Washington, Feb 29 (IANS) Bacteria, long associated with infection and illness in popular imagination, might also precipitate rain, besides affecting climate, agricultural output and even global warming. Brent Christner of Louisiana State University, along with Canadian and French colleagues, recently found evidence of rain making bacteria, Sciencedaily.com reported.

The concept of rain making bacteria isn’t far-fetched. Cloud seeding with silver iodide, or dry ice, has been done for more than 60 years.

Many ski resorts use a commercially available freeze-dried preparation of ice-nucleating bacteria to make snow when the temperature is just a few degrees below freezing.

Christner’s team examined precipitation from global locations and demonstrated that the most active ice nuclei, a substrate that enhances ice formation, are biological in origin.

Dust and soot particles can serve as ice nuclei, but biological ice nuclei are capable of catalysing freezing at much warmer temperatures. If present in clouds, the nuclei may affect the processes triggering precipitation.

“My colleague David Sands from Montana State University proposed the concept of bioprecipitation over 25 years ago and few scientists took it seriously, but evidence is beginning to accumulate that supports this idea,” said Christner.

What complicates this research is that most known ice-nucleating bacteria are plant pathogens, basically germs, which can cause freezing injury in plants, resulting in devastating economic effects on agricultural crop yields.

“As is often the case with bacterial pathogens, other phases of their life cycle are frequently ignored because of the focused interest in their role in plant or animal health.

“The role that biological particles play in atmospheric processes has been largely overlooked. However, we have found biological ice nuclei in precipitation samples from Antarctica to Louisiana - they’re ubiquitous,” said Christner.

Tags: , , , , , , , , , , , , , , , , , , ,

Posted in Environment |