Sonntag, 20. Januar 2013

Das Edaphon im Sturm

Life will find a way, even in the midst of a hurricane

Every hurricane that sweeps through the Gulf of Mexico carries a unique mix of bacteria in its clouds.

Much of our precipitation is likely caused by microbes in clouds. Their surfaces act as "seeds" to attract water and form ice crystals that fall through the cloud as rain or snow. To find out the nature of the bacteria, in 2010 researchers from the Georgia Institute of Technology in Atlanta flew a jetliner through hurricanes Earl and Karl, 10 kilometres above the Earth's surface.

Airborne bacteria make snow to get back home

RAIN is just airborne bacteria's way of getting down to the ground. That's the startling conclusion of an analysis of snow samples from around the world, which reveal that rain-making bacteria are ubiquitous in the atmosphere.

Particles of soot and other tiny pieces of inorganic debris are important "seeds" of precipitation. That's why particles of silver iodide and dry ice are sometimes used to encourage rainfall. The idea that bacterial cells could also trigger rain is not new, but until now no one had appreciated the sheer extent to which biological particles apparently contribute to rainfall.

"They are everywhere in the atmosphere," says Brent Christner of Louisiana State University, Baton Rouge. "It's hard to believe they couldn't have some impact on precipitation."

The particles that Christner is referring to come from bacteria with "ice-nucleating" proteins on their cell surface. For example, the bacterium Pseudomonas syringae has a protein which ...

Solchen Luftreisen verdanken wir vielleicht, daß wir immer noch "genügend" Edaphon im Boden haben - trotz aller Bemühungen es plattzumachen mit tiefgreifenden chirurgischen Pflug-Eingriffen, einseitiger Mangelernährung oder chemischen Zwangs-Infusionen.
Und so kann jede Staubwolke, auch wenn sie den Humus des Böden abtragen sollte, eventuell doch noch ihr Gutes  an anderer Stelle entfalten.

Das Edaphon auf Weltreise

Die US-Weltraumbehörde NASA hat mit Hilfe eines Supercomputers die Verteilung von Staubpartikeln in der Erdatmosphäre dargestellt.

Microbes Survive, and Maybe Thrive, High in the Atmosphere

"Each year, hundreds of millions of metric tons of dust, water, and humanmade pollutants make their way into the atmosphere, often traveling between continents on jet streams. Now a new study confirms that some microbes make the trip with them, seeding the skies with billions of bacteria and other organisms—and potentially affecting the weather. What's more, some of these high-flying organisms may actually be able to feed while traveling through the clouds, forming an active ecosystem high above the surface of the Earth."

"an average of 5100 bacterial cells per cubic meter of air,"

"The researchers cataloged a total of 314 different families of bacteria in their samples."

"two of the 17 most common families of bacteria in the upper troposphere feed on oxalic acid, one of the most abundant chemical compounds in the sky. This observation raises the question of whether the traveling bacteria might be eating, growing, and perhaps even reproducing 10 kilometers above the surface of Earth."

Evidence Of 'Rain-Making' Bacteria Discovered In Atmosphere And Snow

"eb. 29, 2008 — Brent Christner, LSU professor of biological sciences, in partnership with colleagues in Montana and France, recently found evidence that rain-making bacteria are widely distributed in the atmosphere. These biological particles could factor heavily into the precipitation cycle, affecting climate, agricultural productivity and even global warming. Christner and his colleagues published their results on Feb 29 in the journal Science."

Keine Kommentare: