http://www.terradaily.com/reports/The_role_of_bacteria_in_weather_events_999.html
The role of bacteria in weather events A diverse range of particles are capable of serving as IN, but the most active naturally occurring IN are biological in origin, capable of catalyzing ice formations at temperatures near -2 degrees Celsius. The most well-studied biological IN is the plant pathogen Psuedomonas syringae. by Staff Writers New Orleans LA (SPX) May 27, 2011 Researchers have discovered a high concentration of bacteria in the center of hailstones, suggesting that airborne microorganisms may be responsible for that and other weather events. They report their findings at the 111th General Meeting of the American Society for Microbiology in New Orleans. "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," says Alexander Michaud of Montana State University in Bozeman, who presented the research. Michaud and his colleagues analyzed hailstones over 5 centimeters in diameter that were collected on the University campus after a storm in June 2010. The large hailstones were seperated into 4 layers and the meltwater from each layer was analyzed. The number of culturable bacteria was found to be 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," says Michaud. "There is growing evidence that these nuclei can be bacteria or other biological particles." Michaud's 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 formation of ice in clouds, which is necessary for snow and most rainfall events, requires ice nuclei (IN), particles that the ice crystals can grow around. "Aerosols in clouds play key roles in the processes leading to precipitation due to their ability to serve as sites for ice nucleation. At temperatures warmer than -40 degrees Celsius ice formation is not spontaneous and requires an IN," says Brent Christner of Louisiana State University, also presenting at the meeting. A diverse range of particles are capable of serving as IN, but the most active naturally occurring IN are biological in origin, capable of catalyzing ice formations at temperatures near -2 degrees Celsius. The most well-studied biological IN is the plant pathogen Psuedomonas syringae. "Ice nucleating strains of P. syringae possess a gene that encodes a protein in their outer membrane that binds water molecules in an ordered arrangement, providing a very efficient nucleating template that enhances ice crystal formation," says Christner. Aerosol-cloud simulation models imply that high concentrations of biological IN may influence the average concentration and size of ice crystals in clouds, horizontal cloud coverage in the free troposphere, precipitation levels at the ground and even insulation of the earth from solar radiation. "Evidence for the distribution of biological IN in the atmosphere coupled with the warm temperatures at which they function as IN has implied that biological IN may play a role in the Earth's hydrological cycle and radiative balance," says Christner. On 5/26/11 9:53 PM, "BHASKAR M V" <bhaskarmv...@gmail.com> wrote: Hi John Thanks, but the paper is about DMS. DMS is produced by algae growing in oceans. Bioprecipitation (biological rain) is due to bacteria (and algae and fungi) in the atmosphere. regards Bhaskar On Thu, May 26, 2011 at 6:14 PM, JohnDuke <johnd...@johnduke.com> wrote: See Charlson, Lovelock, Andreae, Warren 1987, paper attached (over 2000 citations). ----- Original Message ----- From: "M V Bhaskar" <bhaskarmv...@gmail.com> To: "geoengineering" <geoengineering@googlegroups.com> Sent: Thursday, May 26, 2011 7:09 AM Subject: [geo] Mineral Rain vs Biological Rain Hi All I thought that clouds only formed due to mineral actions and artificial rain by cloud seeding was done by using chemicals like silver iodide. A report on Bioprecipitation says that bacteria, diatoms and fungi too can cause clouds and rain. Can this lead to a biological SRM solution? Fertilize atmosphere over oceans with Diatoms and Nutrients and cause clouds to form and the residual diatoms and Nutrients fall into oceans with the rain and continue to bloom. -------- http://www.livescience.com/14299-bacteria-create-rain-snow-hail.html Surprising Find: Live Bacteria Help Create Rain, Snow & Hail Living bacteria that get whipped up into the sky may be just the spark needed for rain, snow and even hailstorms, research now finds. Alexander Michaud of Montana State University in Bozeman, Mont., found large amounts of bacteria at the centers of giant hailstones. Traditionally, researchers have thought that minerals or other particulates in clouds caused water droplets to glom together until they were large enough to fall as raindrops, snowflakes and hail. The new research shows that a large variety of bacteria, and even fungi, diatoms and algae, persist in the clouds and can be used as precipitation starters, a growing field of study called bioprecipitation. (In order for snow, say, to fall from clouds, particles around which ice crystals can form — called ice nuclei — are needed.) "Minerals were thought to be the dominant ice nucleators in the atmosphere, but they aren't nearly as active as biological particles," said Brent Christner, a microbiologist studying bioprecipitation at Louisiana State University who is presenting the work today (May 24) at the General Meeting of the American Society for Microbiology in New Orleans. Bacterial beginnings For minerals to form ice nuclei, water needs to be much colder than is usually found in clouds, Christner told LiveScience. Bacteria and other living particles that get swept up into the sky may serve as alternative nucleators. Michaud, also presenting at the conference, collected hailstones about the size of golf balls (greater than 2 inches, or 5 centimeters, in diameter) after a huge hailstorm hit Montana in June 2010. He separated the hail into four layers, which are formed as the ice is created and moves up and down through the clouds, accumulating layer upon layer of ice. He found that bacteria levels were highest at the core of the hail. "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," Michaud said in a statement. "There is growing evidence that these nuclei can be bacteria or other biological particles." By determining the temperature at which the hailstones formed, the team found that these bacteria allowed the ice to form at warmer temperatures than otherwise expected. Importance of ice Previously Christner's group found that the widely studied plant pathogen Psuedomonas syringae plays an important role in snow formation all over the world, including Antarctica, where there are few plants. The pathogen is known to be very good at creating ice at temperatures above the normal freezing point of water. These bacteria are equipped with a special substance that binds water molecules in an orderly arrangement, and in these proximities they can more easily form ice particles. When on the ground, the bacteria use this ice to damage plants, causing the plant cells to break apart and allowing the bacteria to enter. "An organism that lives on a plant, where you want to be is back on the ground on another plant. If you have the ability to produce precipitation, fall down and land on a plant, it could be a cycle," Christner told LiveScience. "They could be using this protein as a way to hitchhike on the water cycle." Their presence on the ground, and in the clouds, could influence weather conditions and cycles. ------------------------ regards Bhaskar -- You received this message because you are subscribed to the Google Groups "geoengineering" group. To post to this group, send email to geoengineering@googlegroups.com. To unsubscribe from this group, send email to geoengineering+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/geoengineering?hl=en.
