Do plants make rain?

[carlton-temple]

re above note : The article was on the BBC...15/6/09 entitled "Grey sky research"

[Michaelangelica]

re above note : The article was on the BBC...15/6/09 entitled "Grey sky research"

Thank you

Grey sky research

 

Richard Hollingham

Presenter, Frontiers

 

 

On the edge of an east London rooftop stands an increasingly bedraggled man. Arms outstretched, the rain lashes at his face and cascades down his beard onto sopping clothes.

 

In each hand he holds out a dish containing tiny metal crucibles; he grins as the raindrops ping against the containers.

 

Just another day at the office for University of East London scientist Bruce Moffett and the perfect weather to investigate the biological properties of rain.

 

The idea that bacteria in the clouds cause rain might, at first, rank as one of the more bizarre scientific theories.

Raindrop

It takes a quarter of a million of these to make one litre

 

However, over the past 25 years a small group of scientists has been studying the role bacteria in the clouds might play in our weather and, with papers published in leading scientific journals, the evidence that they're right is beginning to stack up.

 

"It takes something like a quarter of a million rain drops to make one litre," Moffett shouts to me through the wind.

 

Fortunately we don't need a litre. "I've got to make sure I have a raindrop in each." And then it's back to the lab to see what's in there.

 

Ice makers

 

Before rain can fall - at least in temperate climates - the water in clouds has to freeze.

 

But - and you may not believe this - sometimes, water doesn't freeze at 0C. Pure water will not freeze until -40C, and clouds rarely get that cold.

 

So to get water to freeze you need some help. A catalyst such as soot or dust will do the trick but if you want water to freeze at relatively warm temperatures, say around -5C or -6C, bacteria turn out to be the best "ice nucleators".

 

Cindy Morris, a plant pathologist at the French National Research Institute for Agriculture in Avignon, has identified a particular bacterium, Pseudomonas syringae, which is extremely effective at making water freeze.

 

In her lab she takes a tube of water, cooled to -6C (and not frozen), and puts in a single drop of bacterial culture. Within about two seconds, the water has turned to ice.

Rainclouds and cropfields

Bacteria found in crops may make the best "ice nucleators"

 

It's an impressive demonstration. "There's nothing magic about it," laughs Morris. "You can't break the laws of physics."

 

Pseudomonas syringae is found on the leaves of plants. By forming ice, the bacteria damages cell walls, releasing nutrients that it can then feed on.

 

But these organisms can easily get carried off by the wind and, once airborne in the clouds, pull off the same trick and persuade water droplets to freeze. At least that's the theory.

 

BBC NEWS | Science & Environment | Grey sky research

 

Fond this, from NASA, while trying to find BBC site

 

Impact of Polluted Skies on Clouds and Climate

Few parts of Earth’s climate system have such chameleon-like effects as the tiny airborne particles known as aerosols.

The effect of aerosols on clouds has seemed especially paradoxical. Some observations have shown cloud cover increasing as aerosols increased, while other observations showed cloud cover decreasing as aerosols increased.

New research from NASA scientists has finally zeroed in on when aerosols increase clouds and when they decrease clouds.

Regardless of location or weather conditions,

• aerosols that absorb sunlight decrease cloud formation,
  
• while aerosols that don’t absorb much sunlight increase clouds.
  

Impact of Polluted Skies on Clouds and Climate : Image of the Day

And

this

on Night shinning clouds. I wonder if this is like the phosphorescence in the sea at night? Phosphorescence is said to be due to bacteria.

Photo in the News: Mysterious "Night-Shining Clouds" Sighted

[carlton-temple]

Bacteria - plants - rain; one wonders if there may not be a symbiotic connection between certain host plants and their respective rain making bacteria involved ? See L.Margulis ect.

[Michaelangelica]

Bacteria - plants - rain; one wonders if there may not be a symbiotic connection between certain host plants and their respective rain making bacteria involved ? See L.Margulis ect.

I guess that was what I was suggesting with the rider to my question (see post #1 ) "If so do they do it consciously?"

I had to look up Marguilis Wiki says

The underlying theme of endosymbiotic theory, as formulated in 1966, was interdependence and cooperative existence of multiple prokaryotic organisms; one organism engulfed another, yet both survived and eventually evolved over millions of years into eukaryotic cells. Her 1970 book, Origin of Eukaryotic Cells, discusses her early work pertaining to this organelle genesis theory in detail. Currently, her endosymbiotic theory is recognized as the key method by which some organelles have arisen (see endosymbiotic theory for a discussion) and is widely accepted by mainstream scientists. The endosymbiotic theory of organogenesis gained strong support in the 1980s, when the genetic material of mitochondria and chloroplasts was found to be different from that of the symbiont's nuclear DNA.[4]

 

In 1995, prominent evolutionary biologist Richard Dawkins had this to say about Lynn Margulis and her work:

“ I greatly admire Lynn Margulis's sheer courage and stamina in sticking by the endosymbiosis theory, and carrying it through from being an unorthodoxy to an orthodoxy. I'm referring to the theory that the eukaryotic cell is a symbiotic union of primitive prokaryotic cells. This is one of the great achievements of twentieth-century evolutionary biology, and I greatly admire her for it.[5] ”

 

[edit] Theory of symbiotic relationships driving evolution

. . .

She opposes such competition-oriented views of evolution, stressing the importance of symbiotic or cooperative relationships between species.

Lynn Margulis - Wikipedia, the free encyclopedia

 

I just posted an article in the Terra preta sub forum in the "wee beasties" thread on the 1,000 different bacteria we have growing on our OUTSIDE.

We humans seem to be a symbiotic organism ourselves; alive with bacteria, in and out. The "soil" (a symbiotic organism if ever there was one) obviously has a symbiotic relationship with plants.

Can we push the envelope that little bit further and say plants have a symbiotic relationship with the clouds/atmosphere?:smilingsun:

 

Perhaps it is time we asked Gaia for some help in reversing our desecration of the planet?- a new "cooperative relationship between species".:evil::(:)

[Michaelangelica]

Where giant plants dare to grow

BBC - Earth News - Where giant plants dare to grow

 

Which came first the chicken or the egg?

. . .

Species growing at the equator are around 30 times taller on average than those at high latitudes, they found.

 

Their analysis also shows that rainfall has a bigger influence on plant height than temperature or soil fertility.

. . .

 

Instead, the single best predictor of plant height was how much it rained during the wettest month of the year.

"It might seem obvious that plants are taller in the tropics, a. . .

 

"However, there are plenty of tropical ecosystems that are dominated by short plants, such as savannas, and plenty of high-latitude ecosystems that are dominated by very tall plants, such as boreal forests."

. . .

"Instead there turns out to be a remarkable scarcity of very short plants in very warm, wet, productive environments like rainforests."

 

"We hadn't predicted this

 

What's more, she points out, the tallest plants in the world do not grow in the tropics.

[stereologist]

Big plants can be determined by various measures: height, volume, and diameter. There are 3 separate trees for each of these biggest categories. One is a redwood, another a sequoia, and the third is a Montezuma cypress. None of these is in the tropics.

[Michaelangelica]

Big plants can be determined by various measures: height, volume, and diameter. There are 3 separate trees for each of these biggest categories. One is a redwood, another a sequoia, and the third is a Montezuma cypress. None of these is in the tropics.

Yes agreed

I am not really sure what the article/research/survey is trying to say.

[stereologist]

"Instead there turns out to be a remarkable scarcity of very short plants in very warm, wet, productive environments like rainforests."

 

A young northern forest has trees so close that it is too dark to have much growing under it. As the forest increases in size, the density of trees decreases and shorter plants such as ferns begin to grow under the canopy.

 

There are so many different measures of abundance that I wonder what was done.

[maikeru]

Bacteria - plants - rain; one wonders if there may not be a symbiotic connection between certain host plants and their respective rain making bacteria involved ? See L.Margulis ect.

 

I don't think it's symbiotic so much as it is a positive feedback loop that's beneficial for both. More plants, more bacteria, more water. This is unrelated to plants making the weather, but it is related to how plants can drive and sustain beneficial positive feedback loops, and may give a sense of how they could do something similar with promoting rain:

 

Darwin’s Mystery Of Appearance Of Flowering Plants Explained

[Michaelangelica]

A young northern forest has trees so close that it is too dark to have much growing under it. As the forest increases in size, the density of trees decreases and shorter plants such as ferns begin to grow under the canopy.

 

There are so many different measures of abundance that I wonder what was done.

Yes, I was a bit shocked when I first visited the deep north and saw this for the first time.

I was really primordially scared in a dark English Oak forest. A bit like the primordial fear/shock when a bit of seaweed wraps around your leg when surfing. No wonder all those Grimm tales of forests. No wonder we have spent 12,000 years chopping them all down (I was also shocked by the lack of trees in GB --and Europe). Evey time i see the Scottish Highlands on TV I want to race over there and plant trees in the barrenness.

 

 

Here Eucalyptus /'Gums' reflect, scatter and shimmer the light. There is lots of light on the forest floor. The light is very different here.

the "Blue Mountains" are blue because of the amount of Eucalyptus oil in the air. From a distance, the mountains are a 'blue' colour.

Some Mediterranean trees like Olives also let in lots of light. Cottage gardeners love these as they can grow sun loving cottage garden annual favorites like pansies, foxglove, etc., under the trees.

[Turtle]

seems not all raindrops are created equal...erhm...created equally.

 

Myth of raindrop formation exploded - physics-math - 20 July 2009 - New Scientist

Myth of raindrop formation exploded

The short lifetime of a raindrop is a complicated and explosive affair, physicists have revealed. Using high-speed video footage they have solved a longstanding conundrum of what determines the size of raindrops.

 

A century ago, physicists put out sheets of absorbent paper in showers to record raindrop size, and discovered a surprising variety. Most are under a millimetre across, but others span 5 mm – and providing rainfall level is constant, drops exhibit the same variation in every shower. ...

 

it's not clear from the article if all the drops made in the explosions have particles in them, whether from plants or otherwise. :shrug:

[Michaelangelica]

August 4, 2009

. . .

 

. . .

 

A biogeochemical cycle is a pathway by which a chemical element, such as carbon, or compound, like water, moves through Earth's biosphere, atmosphere, hydrosphere and lithosphere.

 

In effect, the element is "recycled," although in some cycles the element is accumulated or held for long periods of time.

 

Chemical compounds are passed from one organism to another, and from one part of the biosphere to another, through biogeochemical cycles.

 

Water, for example, can go through three phases (liquid, solid, gas) as it cycles through the Earth system. It evaporates from plants as well as land and ocean surfaces into the atmosphere and, after condensing in clouds, returns to Earth as rain and snow.

 

Researchers are discovering that biogeochemical cycles--whether the water cycle, the nitrogen cycle, the carbon cycle, or others--happen in concert with one another. Biogeochemical cycles are "coupled" to each other and to Earth's physical features.

 

"Historically, biogeochemists have focused on specific cycles, such as the carbon cycle or the nitrogen cycle," said Tim Killeen, NSF assistant director for geosciences. "Biogeochemical cycles don't exist in isolation, however. There is no nitrogen cycle without a carbon cycle, a hydrogen cycle, an oxygen cycle, and even cycles of trace metals such as iron."

 

. . .

 

. . .

 

 

"Seemingly subtle chemical changes may have large effects," said Cole.

 

"Consider that global climate change is caused by increases in carbon dioxide and methane, gases which occupy less than ½ of one percent of the atmosphere. Now more than ever, we need a comprehensive view of Earth's biogeochemical cycles."

. . .

 

Details about the ESA CBC sessions may be found by visiting the links below.

nsf.gov - National Science Foundation (NSF) News - Earth's Biogeochemical Cycles, Once in Concert, Falling Out of Sync - US National Science Foundation (NSF)

[Michaelangelica]

Cloud seeding works! -using CO2 NO2 (short video)

(In some places at some times)

Catalyst: Cloud seeding - ABC TV Science

 

I wonder if forest fires would warm cold clouds and provide the nucleus-particle to facilitate rain?

Perhaps in the right place at the right time?

[BrianG]

Interesting research, there's far more we don't know about the climate, than we've already learned. If man can mitigate climate, then nature must have found the trick long ago. The best plan might be to find these beasties and domesticate them, rather than limit [ce]CO2[/ce] emissions.

 

Microclimate - Wikipedia, the free encyclopedia

[Michaelangelica]

Interesting research, there's far more we don't know about the climate, than we've already learned. If man can mitigate climate, then nature must have found the trick long ago. The best plan might be to find these beasties and domesticate them, rather than limit [ce]CO2[/ce] emissions.

 

Microclimate - Wikipedia, the free encyclopedia

Yep a good idea-see Terra preta threads on attempts to do this

[Michaelangelica]

Do people make rain?

Pollution Alters Isolated Thunderstorms:

Wind Shear Strength Determines Whether Pollution Swells or Saps Storms

 

ScienceDaily (Dec. 17, 2009) — New climate research reveals how wind shear -- the same atmospheric conditions that cause bumpy airplane rides -- affects how pollution contributes to isolated thunderstorm clouds.

Under strong wind shear conditions, pollution hampers thunderhead formation. But with weak wind shear, pollution does the opposite and makes storms stronger.

. . .

This finding may provide some guidelines on how man-made aerosols affect the local climate and precipitation,

. . .

Additional analyses described the physics underlying these results.

Water condensing onto aerosol particles releases heat, which contributes to convection and increases updraft speed.

The evaporation of water from the cloud droplets cools the air, which reduces the updrafts.

In strong wind shear conditions, the cooling effect is always larger than the heating effect, leading to a reduction in updraft speed.

Pollution alters isolated thunderstorms: Wind shear strength determines whether pollution swells or saps storms

[Michaelangelica]

Satellite observations suggest vegetation encourages rainfall in Africa.

by Richard van Noorden

Nature News

 

More rain makes for more plant growth: that much is obvious. But now a statistical study of satellite images has added weight to the reverse notion: more plants also make for more rain.

 

The result adds to the impetus to preserve green spaces in dry regions, in order to help prevent deserts from growing and encroaching on agricultural land.

 

Greenery can have a number of effects on a local climate.

Plants are thought to transfer moisture from the soil into the air by evaporation from their leaves, and hold water in the soil close to the surface, where it can also evaporate.

What is more, the darker surfaces of plants compared to sandy deserts also absorb more solar radiation, which, along with their rough texture, can create convection and turbulence in the atmosphere.

This might create more or less rainfall.

 

All of these effects have been incorporated into climate models.

But there has been disagreement about which effects were dominant and why, and how much impact it all has.

 

The new work concludes that vegetation effects account for around 30% of annual rainfall variation in Africa's Sahel region. The results are reported in Geophysical Research Letters.

Biology News: More plants make more rain