Clouds, can be said to both common and mysterious. They are when the water vapor condense into tiny water droplets or ice crystals formed, this process often fluttered in the air of small particles called aerosols and accelerated. Aerosol's role is to let the water get a certain level of attachment, but why are the clouds and precipitation and sometimes pour such as injection, sometimes without, we still know nothing.
The answers were related to the physical properties of ice. Clouds they contain water droplets large enough to overcome the updraft in the atmosphere, will produce rain or snow. In most cases, falling along with the freezing process---the formation of ice crystals faster than liquid water droplets, which means they haven't been blown by the wind blowing or drop weight has been reached before they evaporate or disappear. Despite the seemingly magical, liquid water can be kept in the atmosphere to-40 degrees Celsius. Molecular secrets behind this phenomenon is still confusing, but clouds of water droplets usually need a little help to form ice.
That power is "ice core" forms, these airborne particles will provide core to water molecules, water molecules arranged in a lattice structure of ice crystals around it. But they cannot be more than-15 degrees centigrade temperature potential pregnancy in ice crystals, all clouds formed over the land, which is equivalent to half of its internal temperature. In these ordinary clouds, seems to hide some kind of mystery.
Sands discovery
The spring of 1978, United States North of Montana wheat faced a serious threat. No matter how Dawei·sangzi seeds and soil, crops are withering disease of black and blue. Thus, his instinctive hired a small plane to board the blue sky, the clouds to find the crux of the issue.
Sands had some micro-organisms are found in the clouds by instruments, haunting doubts for many years and finally found the answer. Not only that, he also began to believe that their findings will solve this long-standing mystery how it will rain in the sky.
Sands believes that drizzle and rain hat is living in cloud of microbes. This insight has not completely accepted by atmospheric scientists, they blindly staring at the dust and soot and not willing to listen to the plant pathologist. Many times that their point of view and a little case, Sands returned to Montana State University, continue plant wilt research.
However, the discoveries over the past years are keeping things moving in the expected direction. In recent years a series of clouds aerial returned evidence also indicates: the sky seems to be awash in "hijacking" microorganisms in the weather, certain bacteria are the key to making rain. There are even signs: in recent years, some of the worst drought in history, was caused by humans disturbing the delicate balance between bacteria and plants.
High-flying life controls the clouds
In recent years, scientists have found various flying high in the sky, may control the cloud of micro-organisms. Such as Georgia Tech Star SI·kangsitandingyidisi, who led the team to the monograph published in 2013, will visit the 2010 Earl and Carl Hurricane while crossing the Caribbean Sea, Mexico Bay, the Atlantic Ocean and the Americas collected up to 10,000 metres over the sample. They determined 314 different bacteria, most of which are active. Also found in soil and dust particles such as cells, "these cells have the potential to significantly affect the formation of clouds. "Kangsitandingyidisi said.
These organisms may be inadvertently carrying the dust were towed along. To find out whether microbial life forms can cause rain, and see what they did inside the clouds. Atmospheric chemist at UC San Diego jimu·pulase is from Wyoming, Caribbean haishengkeluyidao draw the ice and rain clouds over the Sierra Nevada Mountains. She and her colleagues found after analyzing the chemical composition of the particles of ice crystals form, most cumulonimbus cloud particles about 40% show is closely related to biological parentage. Prasse also found that these biological particles often overlap and came all the way around the world in dust form, generally from sub-Saharan Africa or China. "In one case we follow the dust floating across the Pacific, have witnessed a continuing snowfall in advance. "She explained. These factors together and the conclusion is formed by heart: microbes did bring about a warm cloud of ice.
As the United Kingdom University of Leeds, dannier·aoshaliwen as confirmed, soot and mineral particles are abundant content and thus more likely to dominate, but we also have to consider the other factors of fine organic particles, for example the same function, fragments of fungi. These nano-particles in the soil of inventory to be reckoned with, only visible under a microscope in the marine phytoplankton, similarly no lack of splash surf waves hurled into the atmosphere by the sea ice cores.
Bulunte·kelisitena at the University of Florida also noted that microorganisms may not be able to control the impact of global precipitation patterns in some areas. "We can't use bacteria to explain weather changes, but I think in some conditions, in certain periods of the year, the material enters the atmosphere hang and have a significant effect. "He said.
Bacteria are key components of rain-making factory
If the bacteria are affecting our weather, even if limited to special type of cloud is no exception, so they are likely to be self-contained and rain-making factory key elements of it? Sands in Pseudomonas SP bacilli found hidden in the clouds shortly after, put forward the idea of a feedback loop: Microbe perched leaves rising into the atmosphere, where ice crystals and spawned into the rain to ensure they own to sow, also provided an opportunity to quench their thirst for their plant hosts.
As a host plant also plays a role here, and that's rain provides cozy home after the handover. A record dated back to 1956, and listing from Australia southern segregation of ice nucleation particles in air samples collected at the same time, very rarely reveal the intriguing patterns. Morris and retired meteorologist jisi·Bige this data with meteorological records and land use to compare and found in some observation sites, after a rain storm will greatly enhance the probability of rainfall, agricultural land especially prone to this phenomenon. In Morris's view, this may be because the plants have become major ice nucleation active bacteria "real estate".
At present, Morris and sands are examining the last century throughout the United States over more than 1000 West of rainfall patterns, search feedback loops, including clouds, plants and bacteria are achieved. Research to date shows that the Sierra Nevada Mountains and the agricultural areas around Phoenix, Arizona there is a strong tendency in certain rainfall feedback. "Some plants seem to be released after the rainfall more ice cores, which lead to another cycle of rainfall. "Mr Sands said. Because of this, Sants believe that began since the dawn of agriculture, people have been unknowingly change the weather. "Farmers were planting as well as plant food bacteria, thus resulting in a ride in the rain. "He said. That also means intensive cultivation of only one or two types of ice nucleation host crops, are likely to have disastrous consequences.
United States wheat in the Midwest in the early 20th century story is one example. Planted crops are especially vulnerable against wheat rust, a fungal pathogen, it happens to reaching perfect ice cores. It seems counterintuitive, but Morris now popular doubt succession of wheat rust in creating the dust bowl conditions, led to the North American Prairies in the 30 played a role in the disaster. "Tillage will release thousands of wheat rust spores in the process, creating ice core of so many not able to grow enough to rain. "She said," too many of our ice cores, the clouds contain begins. ”
Foster special microbiological control the future weather
If the past weather is that we inadvertently casts, then our future consciously to do? Send a plane, by spraying silver iodide to generate ice, the United States has a long history. In the last year alone, Los Angeles in response to California's ongoing drought and catalytic contractor allocated $ 500,000 to the clouds, finally for lack of evidence of silver iodide to increase chances of rainfall and lead to public outcry.
Sands believes that natural ice channels which could offer a better solution. He and Morris were exploring how to fit some potential pregnancy planted plants of ice nucleation active bacteria, whereby the possibility to squeeze more rain sky. This requires identifying and selectively breeding stock of frozen microbes is the most abundant plant, to enable them to settle on the ground, is designed to cultivate enough created ice core without impeding the cloud of microbes.
The other hand, Sands and Morris told Syria cooperate, analysis of 25 species of wheat, Pseudomonas SP bacilli were found harmless in the strains of wheat. As a result, researchers will be able to use without disease of wheat seed varieties to be "packaged", increasing the number of leaves rain-making bacteria. These bacterial seed companies will eventually be loaded on the seed, by changing the host of micro flora to create conditions conducive to precipitation.
However, the drought is not going to disappear. "If there is no water vapour in the air, you will not be able to induce rainfall. "Morris said. No matter how skilled we became in catalytic clouds, falls somewhere in the global weather patterns will always depend on the moisture content---and they are changing fast. Global warming is one of the biggest challenges, because even if scientists can identify and nurture contribute to powerful micro-organisms, they are likely to become more warm weather becomes too hot to display their skills.
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