Bacteria's role in influencing weather events revealed

A new study has found the presence of high concentration of bacteria in the centre of hailstones, explaining the role of these microorganisms in various weather events.

"Bacteria have been found within the embryo, the first part of a hailstone to develop. The embryo is a snapshot of what was involved with the event that initiated growth of the hailstone," said researcher, Alexander Michaud of Montana State University.

Michaud and his team analysed hailstones over 5 centimeters in diameter that were collected from the University campus after a storm. They separated the large hailstones into 4 layers and analyzed the melt water from each layer.

The researchers found that the number of culturable bacteria was highest in the inner cores of the hailstone.

"In order for precipitation to occur, a nucleating particle must be present to allow for aggregation of water molecules. There is growing evidence that these nuclei can be bacteria or other biological particles," Michaud added.

The new research is part of a growing field of study focusing on bioprecipitation, a concept where bacteria may initiate rainfall and other forms of precipitation including snow and hail.

The study has been presented at the general meeting of the American Society for Microbiology in New Orleans.