Broken glass yields clues to climate change

December 27, 2010
Dust particles in the atmosphere range from about 0.1 microns to 50 microns in diameter (microns are also known as micrometers, abbreviated as µm). The size of dust particles determines how they affect climate and weather, influencing the amount of solar energy in the global atmosphere as well as the formation of clouds and precipitation in more dust-prone regions. The NASA satellite image in this illustration shows a 1992 dust storm over the Red Sea and Saudi Arabia. Credit: Composite illustration ©UCAR. This image is freely available for media use. Please credit the University Corporation for Atmospheric Research.

Clues to future climate may be found in the way that an ordinary drinking glass shatters. A study appearing this week in Proceedings of the National Academy of Sciences finds that microscopic particles of dust, emitted into the atmosphere when dirt breaks apart, follow similar fragment patterns as broken glass and other brittle objects. The research, by National Center for Atmospheric Research (NCAR) scientist Jasper Kok, suggests there are several times more dust particles in the atmosphere than previously believed, since shattered dirt appears to produce an unexpectedly high number of large dust fragments.

The finding has implications for understanding future because dust plays a significant role in controlling the amount of solar energy in the atmosphere. Depending on their size and other characteristics, some reflect solar energy and cool the planet, while others trap energy as heat.

"As small as they are, conglomerates of dust particles in soils behave the same way on impact as a glass dropped on a kitchen floor," Kok says. "Knowing this pattern can help us put together a clearer picture of what our future climate will look like."

The study may also improve the accuracy of weather forecasting, especially in dust-prone regions. Dust particles affect clouds and precipitation, as well as temperatures.

Shattered soil

Kok's research focused on a type of airborne particle known as mineral dust. These particles are usually emitted when grains of sand are blown into soil, shattering dirt and sending fragments into the air. The fragments can be as large as about 50 microns in diameter, or about the thickness of a fine strand of human hair.

The smallest particles, which are classified as clay and are as tiny as 2 microns in diameter, remain in the atmosphere for about a week, circling much of the globe and exerting a cooling influence by reflecting heat from the Sun back into space. Larger particles, classified as silt, fall out of the atmosphere after a few days. The larger the particle, the more it will tend to have a heating effect on the atmosphere.

Kok's research indicates that the ratio of silt particles to clay particles is two to eight times greater than represented in climate models.

Since climate scientists carefully calibrate the models to simulate the actual number of clay particles in the atmosphere, the paper suggests that models most likely err when it comes to the number of silt particles. Most of these larger particles swirl in the atmosphere within about 1,000 miles of desert regions, so adjusting their quantity in computer models should generate better projections of future in desert regions, such as the southwestern United States and northern Africa.

Additional research will be needed to determine whether future temperatures in those regions will increase more or less than currently indicated by computer models.

The study results also suggest that marine ecosystems, which draw down carbon dioxide from the atmosphere, may receive substantially more iron from airborne particles than previously estimated. The iron enhances biological activity, benefiting ocean food chains, including plants that take up carbon during photosynthesis.

In addition to influencing the amount of solar heat in the atmosphere, dust particles also get deposited on mountain snowpacks, where they absorb heat and accelerate melt.

Glass and dust: Common fracture patterns

Physicists have long known that certain brittle objects, such as glass or rocks, and even atomic nuclei, fracture in predictable patterns. The resulting fragments follow a certain range of sizes, with a predictable distribution of small, medium, and large pieces. Scientists refer to this type of pattern as scale invariance or self-similarity.

Physicists have devised mathematical formulas for the process by which cracks propagate in predictable ways as a brittle object breaks. Kok theorized that it would be possible to use these formulas to estimate the range of dust particle sizes. He turned to a 1983 study by Guillaume d'Almeida and Lothar Schueth from the Institute for Meteorology at the University of Mainz in Germany that measured the particle size distribution of arid soil.

By applying the formulas for fracture patterns of brittle objects to the soil measurements, Kok determined the size distribution of emitted dust particles. To his surprise, the formulas described measurements of dust particle sizes almost exactly.

"The idea that all these objects shatter in the same way is a beautiful thing, actually," Kok says. "It's nature's way of creating order in chaos."

Explore further: New class of airborne particles unaccounted for in climate models

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22 comments

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lexington
2.6 / 5 (5) Dec 27, 2010
Cue Tea Party in the comment section.
jonnyboy
2.3 / 5 (6) Dec 27, 2010
Free at last! Free at last! Lordy, Lordy, a PHYSORG article without political beliefs, just plain hard science.
Noumenon
4.6 / 5 (54) Dec 27, 2010
Lets define "hard science";
"Karl Popper, the late, great philosopher of science, noted that for something to be called scientific, it must be, as he put it, "falsifiable." That is, for something to be scientifically true, you must be able to test it to see if it's false. That's what scientific experimentation and observation do. That's the essence of the scientific method."

Unfortunately, the prophets of climate doom violate this idea. No matter what happens, it always confirms their basic premise that the world is getting hotter. The weather turns cold and wet? It's global warming, they say. Weather turns hot? Global warming. No change? Global warming. More hurricanes? Global warming. No hurricanes? Global warming.
lexington
1.8 / 5 (5) Dec 27, 2010
Except that climate change doesn't pretend to predict environmental conditions in a particular area (or maybe you're claiming that there was a decade when the entire planet had nothing but rain). I'm pretty sure climatologists have only ever said that more hurricanes are a sign of global warming.
Noumenon
4.6 / 5 (55) Dec 27, 2010
Except that climate change doesn't pretend to predict environmental conditions in a particular area (or maybe you're claiming that there was a decade when the entire planet had nothing but rain). I'm pretty sure climatologists have only ever said that more hurricanes are a sign of global warming.

Really? They constantly use local conditions as evidence for their speculation of global climate when it serves them.

"According to Dr David Viner, a senior research scientist at the climatic research unit (CRU) of the University of East Anglia, within a few years winter snowfall will become “a very rare and exciting event,... Children just aren’t going to know what snow is,”"

Similar crazy statements were made after Katrina about predictions of hurricanes, strength and number.

Also, I NEVER here them correct the hysterical statements coming from the UN and leftist politicians, aiming for redistribution of wealth.
Noumenon
4.6 / 5 (55) Dec 27, 2010
...
This year is exceptionally cold,.. and was stated it was because of climate change.

My point is there is "hard sciences", like biology, chemistry, physics, that advance only by successfully making and testing predictions, and then there are those sciences which can only speculate. AGW is scientific speculation mixed with political motivation. The basic science is physics and sound, the data is questionable and the conclusions, wildly speculative both in predictions and especially solutions.
Quantum_Conundrum
2 / 5 (8) Dec 27, 2010
Except that climate change doesn't pretend to predict environmental conditions in a particular area (or maybe you're claiming that there was a decade when the entire planet had nothing but rain). I'm pretty sure climatologists have only ever said that more hurricanes are a sign of global warming.


Well see, that isn't even correct.

If there really was a 5 degree C rise in atmospheric temperature, this would produce more energy in the jetstream and also produce stronger tropical upper troposphere troughs, which would shear hurricanes more often. the result is that there would be FEWER hurricanes. However, because ocean temperatures would be hotter, the conditions might line up to make a higher than average number of those hurricanes that don't get sheared to become a super-cane.

Increasing atmospheric temperature reduces the number of hurricanes via shear and first law of thermodynamics.

Increasing ocean temperature increases intensity of hurricanes if not sheared.
dan42day
2.1 / 5 (9) Dec 27, 2010
Climate change will take care of itself. If it gets too extreme, human populations will drop to a few hundred million.

Problem solved.
Quantum_Conundrum
1.9 / 5 (8) Dec 27, 2010
Hurricanes move energy from a hot reservior (ocean) to a cold reservoir (atmosphere.) In the AGW hypothesis, the atmosphere is supposed to warm due to greenhouse effect. If both the atmosphere and the ocean are warmed by the same amount, then the potential work, and therefore the potential power of a storm, is about the same on average. However, the maximum potential goes up. But the maximum potential is only a ridiculously rare event whereby atmospheric cold pocket with a high pressure aloft is lined up with a surface low over very warm water with no shear.

But if the atmosphere has more energy, then there is more shear, so harder to form a hurricane in the first place.

Moreover, things like the huge dust plumes from dust storms from Africa kill hurricanes because it interferes with the heat transfer mechanism that powers them in the first place.

So you will have fewer hurricanes, but a higher precentage of them will be category 5.
eachus
2.3 / 5 (6) Dec 27, 2010
Hurricanes move energy from a hot reservior (ocean) to a cold reservoir (atmosphere.) In the AGW hypothesis, the atmosphere is supposed to warm due to greenhouse effect.


In real science, a hypothesis, when falsified, is discarded. Modifying a theory and trying again is sometimes appropriate, but only when it is a refinement, rather than trying to explain away a solid negative result.

The AGW hypothesis says that heat transport by radiation will be stopped by CO2 in the atmosphere. Unfortunately for the AGW true believers, most of the heat transport in the atmosphere involves thermals, air circulation in clouds, and precipitation. (Clouds also change the amount of solar heat that reaches the surface.)

Just to remind you though, I think that the effects of increased CO2 on humans are serious and getting worse. AGW is just a distraction from what we should really be worried about.
Going
2.6 / 5 (5) Dec 28, 2010
Climate science makes mathematical models of the Earth which mimic the way energy moves in the atmosphere. Either these models accurately reflect changes in the Earth's climate or they don't. If they don't then new ones are developed which behave in a more realistic way. This is clearly a science by Poppers definition. Popper saw science as progressing by conjecture and refutation. Climate sceptics seem to operate by responding to legitimate conjecture about climate, not by any refutation but merely repeating over and over that they don't believe it. Hence the name "denier"
GSwift7
3.2 / 5 (5) Dec 28, 2010
@Going:

I don't know the original source, but the term "denier" is used in an attempt to compare climate sceptics to people who claim the Nazi Holocaust never happened. It's been used by people like Joe Romm, Al Gore, Jeffrey Sachs, Jim Hansen and Michael Mann in that context. It's a deliberate ethical attack against anyone who questions any aspect of AGW alarmism.

I think maybe some of you misunderstood Jonnyboy's comment. Usually, articles on this web site which are even remotely related to climate theory will have silly little comments, that have nothing to do with the story, thrown in at random places in the article. It is nice to see an article that relates to climate change theory without any editorial commentary mixed in with the summary of the scientific findings. They don't say, for example "which will lead to the end of the world as we know it", in the middle of a quote from the study's spokesperson.

This is a nicely written article.
GSwift7
Dec 28, 2010
This comment has been removed by a moderator.
Quantum_Conundrum
3.2 / 5 (5) Dec 28, 2010
I see I got some low feedback, probably from people who bought into the weather channel and news media's WRONG analysis of hypothetical global warming on tropical cyclones. One hyped thing they do is blame hyper-active years like 2005 on AGW. However, there were several hyper-active years 70 and 80 years ago, when any man-made influence would have been at a minimum.

Of interest is the fact there has never been a category 5 hurricane on record in the first half of October, while there are 4 cat 5's on record for the second half of October.

Then there's the fact the strongest landfalling hurricane in world history was Labor Day, 75 years ago, and it was almost as strong when the eye was on land as Wilma was at peak intensity over water.

If you want to read an expert analysis on theory about what happens to hurricanes in global warming, I suggest reading some from Dr. Jeff Masters or Dr. Emanuel Kerry.
LariAnn
2.3 / 5 (4) Dec 28, 2010
Something can be scientific and hence, falsifiable, and yet at the same time few or none working in that field have any desire or motivation to falsify it. Sometimes, when reading any article about biology, for example, I marvel about how EVERYTHING has to be presented as further proof of evolution, much as some religious folks see everything as proof of the existence of God. Evolution, like AGW, may be falsifiable, but does anyone really want to falsify it, or is the status quo too unyielding and merciless to allow for a professional scientist to do so without sacrificing his/her career?
GSwift7
1 / 5 (1) Dec 28, 2010
Quantum:

I rated you low because the predicted effects of warming on tropical storms are a bit more complicated than that. For example, the effect in the Atlantic is different than the predicted effect in the Pacific. The latest assessment I have seen, based on CESM 1.0, says that Atlantic tropical storms will decrease while pacific storms will stay the same, but change track a bit. I'm having trouble posting my link to the American Meteorological Society page where that abstract is posted though.
Quantum_Conundrum
2 / 5 (4) Dec 28, 2010
LariAnn:

Not only is everything presented as further proof of evolution, they always take it a step farther than that. On many scientific programs andlectures, evolution is practically presumed to be true, almost axiomatic, and even "personified," which is ridiculous.

Examples:

"Evolution has made the Cheetah the fastest cat and one of the fastest animals on earth."

"The shark is a highly evolved predator."

And these things will be stated as "fact," even though they are not fact at all. They are hypotheticals disquised as "fact".

Moreover, this is how they now do EVERY branch of science: biology, cosmology, geology, weather/climatology(especially AGW.)

The statement, "The shark is an efficient predator," is a factual statement.

Any statement implying evolution has or had anything to do with the shark is a theoretical or hypothetical statement, and has no business being presented as "factual".
GSwift7
1 / 5 (1) Dec 28, 2010
I still can't post the link I wanted to post, Quantum.

Try google'ing the following and take the first link that shows up.

Preliminary evaluation of CESM 1.0 20th century and select future climate runs within the Intra-Americas Sea region
Quantum_Conundrum
1 / 5 (1) Dec 28, 2010
Yeah, notice this line:

"Studies of tropical storm tracks for the projected warmer conditions of the 21st century find reduced storm track activity in the N. Atlantic..." (from the link you gave.)
GSwift7
1 / 5 (1) Dec 28, 2010
Yes, I wasn't saying you are wrong. It's just that the cause and effect is a lot more complicated than what you said, and the North Atlantic is only one region amongst many. The Indian Ocean and South Pacific are a different case entirely. I am actually looking forward to the full presentation of tropical storm predictions. I remain skeptical of such predictions, but the science behind the predictions is interesting to me. From what I can find, this newest model is a vast improvement, but they still don't really model cloud feedback on a scale that will give meaningfull tropical storm frequency and magnitude predictions.
Parsec
not rated yet Dec 31, 2010
Actually its not quite true that climate scientists use only local measurements to determine temperature changes. Satellite's measure in an almost continuous pattern. Also its not a single place, all of these local measurements which are direct, combined with a huge number of different proxies, indicate that the average global temperature is rising. This is actual observation.

AGW deniers must come up with alternate theories (that CO2 changes are responsible) to explain the observed changes before they can claim some sort of scientific basis for their disbelief. It seems to me that most comments pair rejection of the science with a particular political viewpoint, which leads me to believe its more about ideology than real scientific disagreement.
StandingBear
1 / 5 (1) Jan 01, 2011
This dust measurement, localization, and size distribution model appears to account for one reason why deserts stay hot. If the silt could be reduced over desert regions which are constantly adding to the silt load by recurring dust storms, then those areas will start to cool and maybe begin to receive a more normal rainfall pattern. Arid Arab nations would be much interested in this as a way to gain soil area through reversal of desertification. Egypt could certainly use this, but may have to have cooperation from arid nations to the west of it. Maybe a way to somehow stabilize vast areas of loose sand from sandstorm dust pickup

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