American Society for Microbiology
The role of bacteria in weather events
NEW ORLEANS, LA – May 24, 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 today 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.
And not one mention of CO2,sheesh.
Excuse me while I break proper WUWT decorum for a moment. Ladies, please avert your eyes.
Holy shit!
That is all.
Repeat the CLOUD experiment with bacteria in the mix
“suggesting that airborne microorganisms may be responsible for that and other weather events” . . . .
This is a pretty big leap for one sample storm studied . . .
Rain has to have something to form around also . . . . This is the basic 101 meteorology thirty + years ago.
This is part of the biggest and least reported story in science, with lots of branches popping up all over the place. (Another interesting branch is the role of bacteria in communication among plants; another is the role of our gut bacteria in controlling our emotions…..)
If I had to give advice to a youngster considering a career in science, it would be
“One word, young man: Bacteria.”
Fascinating stuff.
May be a dumb question, but is it possible the bacteria come from land based dust that is pulled upward from the thunderstorm formation?
Control The Language, Control the Thoughts says:
May 24, 2011 at 1:47 pm
Fascinating stuff.
That was me – I forgot to change my name back since my last post. I do find this stuff fascinating!
You should contact Gavin Pretor-Pinney, who wrote the Cloud Spotter’s Guide and started the Cloud Appreciation Society.
He did an experiment for a BBC TV programme about clouds, flying into a cloud and collecting samples of the air outside in Petri dishes. He had been told by a scientist that it was possible bacteria seeded clouds, and wanted to test what was there.
I have not seen the programme unfortunately, so I don’t know the result., but I was the pilot who flew him up into the cloud, in a little Piper Seneca over Cambridgeshire.
FWIW, P. syringae has been used to help make snow since 1985. If this rather long URL doesn’t work, try Googling |bacteria snow making snowmax 1985|.
http://books.google.com/books?id=ZOQDAAAAMBAJ&pg=PA90&lpg=PA90&dq=bacteria+snow+making&source=bl&ots=5_lPAx04zq&sig=I0iwRi8Yl_gkvBcxGC3xZZUB0vE&hl=en&ei=bRjcTea3JM3r0QGPiJXoDw&sa=X&oi=book_result&ct=result&resnum=8&ved=0CFgQ6AEwBw#v=onepage&q&f=false
See also http://www.telemet.com/snow/snomax.asp
Shub Niggurath says:
May 24, 2011 at 1:30 pm
> Repeat the CLOUD experiment with bacteria in the mix
Svensmark’s hypothesis applies to clean maritime air and offers a path for condensation nuclei to form in clean air. My guess is that P. syringae would dominate the DMS/SO2/suphate nuclei CLOUD is studying.
Or older . . . The role of molds and bacteria in the formation of cheese . . . .
http://en.wikipedia.org/wiki/Blue_cheese
I know some hate Wikipedia . . . . but . . .
Oh wait, the role of yeast in wine formation . . .
I hope this is not example of trolling . . . if it is, I do not know what the point of this story is . . .
“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”
For just a second I was wincing and bracing myself for some remark that increased bacteria may be caused by climate change….but it never came. I’m still smarting from a recent flurry of “caused by CC” assertions, I think.
Richard says:
May 24, 2011 at 1:52 pm “flying into a cloud and collecting samples of the air outside in Petri dishes. ”
Be much cheaper to test rain samples . . . . or haven’t you heard . . . that there has been a governmental Debt Crisis worldwide
bikermailman says:
May 24, 2011 at 1:48 pm
May be a dumb question, but is it possible the bacteria come from land based dust that is pulled upward from the thunderstorm formation?
======
I was wondering where “high concentration of bacteria” was coming from as well. Although, I wonder what they mean by high — makes it sound like a remake of the Andromeda Strain.
Apparently, large hail is primarily created in the strongest updraft regions of the severest convective storms. The moisture is drawn up from the base of the storm and comes in contact with ice crystals from the top of the storm.
I guess it seems logical that the ice from higher altitudes would contain less bacteria than the seed moisture (sleet) from the updraft that’s necessary to form the core for hail.
Apparently, the longer the hail remains aloft, the larger the hail stone. The largest found in the US was 7″ in diameter.
The GCM modelers now face a choice:
a) rework their models and include a bacterial cloud seeding component
b) use it as a fudge factor to have better hindcasting and more catastrophic future projections.
If i were them i would argue: Increased CO2 promotes (by some hypothesized but highly likely mechanism) cloud seeding by bacteria, reducing cloud cover rapidly once a critical concentration of CO2 is reached, say in 2050; and from there temperatures will go up up up…
Thinking about it, i could write a book about it and be the next Neil Postman / Jared Diamond / Al Gore…
Finally! A new standard for measuring hail stones has been set. Forget quarters, golf balls, grapefruit – “as big as a $20 bill” will be the phrase to use. Be sure to wear a hardhat!
As a kid we were taught in Kansas, that nitrogen fixing bacteria were one of the wonderful things to fall in rain, I would expect, that some of them are IN as well, maybe just not as good for hail formation. I could imagine that scanning a cloud for bacterial types might let you predict the probability of having hail fall from the system.
Seems unlikely to me, I think it more probable that the nuclei are formed from soil and disintegrated vegetation particles, carried aloft in the wind. The bacteria are along for the ride.
Perhaps the extracellular polymeric substances of the bacteria help the process along, but I can’t think it would be very significant considering the miniscule amounts, compared to the mass of dust plus liquid water & forming ice crystals.
See Figure 5 (no paywall): http://journals.ametsoc.org/doi/pdf/10.1175/1520-0469(1971)028%3C0391%3ANIFNIS%3E2.0.CO%3B2
Laurie Bowen says:
May 24, 2011 at 2:08 pm
According to Steny Hoyer, there’s not a problem at all!
http://www.newsbusters.org/blogs/edwin-mora/2011/05/24/steny-hoyer-america-not-broke
At that size, forget the hard hat. Make sure you have your organ donor card!
I wonder if they corrected for the dilution factor or did they just use a statistical population count in absolute value? The greater the diameter, the more diluted the count is.
so, it’s not MAN-made ‘climate change’, after all!
Stupid question time. How long would it take for one of those monster hailstones to form? I find it amazing that an object could stay aloft long enough, even with strong updrafts, to reach that size. Whew!