The Cloudspotter's Guide

A unique and far-ranging romp through science, history, art, and pop culture -- written for anyone who’s curious about those fluffy, floating, ever-shifting cotton balls in the sky...

Where do clouds come from? Why do they look the way they do? And why have they captured the imagination of timeless artists, romantic poets, and every kid who’s ever held a Crayon? Veteran journalist and lifelong sky-watcher Gavin Pretor-Pinney reveals everything there is to know about clouds, from history and science to art and pop culture. Cumulus, nimbostratus, and the dramatic and surfable Morning Glory cloud are just a few of the varieties explored in this smart, witty, and eclectic tour through the skies.

Generously illustrated with striking photographs and line drawings featuring everything from classical paintings to lava lamps, children’s drawings, and popular advertisements, The Cloudspotter’s Guide will have enthusiasts, poets, weather watchers, and the just plain curious floating on cloud nine. Looking up will never be the same again.

Liquid breathing

Liquid breathing is a form of respiration in which a normally air-breathing organism breathes an oxygen-rich liquid (usually a perfluorocarbon), rather than breathing air. It is used for medical treatment and could some day find use in deep diving and space travel. Liquid breathing is sometimes called fluid breathing, but this can be confusing because both liquids and gases can be called fluids.

Methods of application

Despite recent advances in liquid ventilation, a standard mode of application of perfluorocarbon (PFC) has not been established yet.

Total liquid ventilation

Although total liquid ventilation (TLV) with completely liquid filled lungs is beneficial, the necessity for the liquid filled tube system that contains pumps and heater and membrane oxygenator to deliver and remove tidal volume aliquots of conditioned perfluorocarbon to the lungs is a disadvantage with regard to gas ventilation. One research group led by Thomas H. Shaffer has maintained that with the use of microprocessors and new technology, it is possible to maintain better control of respiratory variables such as liquid functional residual capacity and tidal volume during TLV, than with gas ventilation. ^[1][2][3][4].

[edit] Partial liquid ventilation

In contrast, partial liquid ventilation (PLV) is a technique in which a PFC is instilled into the lung to a volume approximating functional residual capacity (approximately 40% of TLC (Total Lung Capacity)). Conventional mechanical ventilation delivers tidal volume breaths on top of this. This mode of liquid ventilation is technically more viable than total liquid ventilation as it can utilise technology currently in place in neonatal intensive care units (NICU) worldwide.

The influence of PLV on oxygenation, carbon dioxide removal and lung mechanics has been investigated in several animal studies using different models of lung injury^[5] Clinical applications of PLV have been reported in patients with Acute Respiratory Distress Syndrome (ARDS), meconium aspiration syndrome, congenital diaphragmatic hernia and Respiratory Distress Syndrome (RDS) of neonates. In order to correctly and effectively conduct PLV, it is essential to (1) properly dose a patient to a specific lung volume (10-15 ml/kg)to recruit alveolar volume and (2) redose the lung with PFC liquid (1-2 ml/kg/hr) to oppose PFC evaporation from the lung. If PFC liquid is not maitained in the lung, PLV can not effectively protect the lung from biophysical forces associated with the gas ventilator.

New application modes for PFC have been developed^[6].

[edit] PFC vapor

Vaporization of perfluorohexane with two anesthetic vaporizers calibrated for perfluorohexane has been shown to improve gas exchange in oleic acid induced lung injury in sheep ^[7]. Predominantly PFCs with high vapor pressure are suitable for vaporization.

Aerosol-PFC

With aerosolized perfluorooctane, significant improvement of oxygenation and pulmonary mechanics was shown in adult sheep with oleic acid-induced lung injury. In surfactant-depleted piglets, persistent improvement of gas exchange and lung mechanics was demonstrated with Aerosol-PFC ^[8]. The aerosol device is of decisive importance for the efficacy of PFC aerosolization, as aerosolization of PF5080 (a less purified FC77) has been shown to be ineffective using a different aerosol device in surfactant-depleted rabbits (Kelly). Partial liquid ventilation and Aerosol-PFC reduced pulmonary inflammatory response ^[9].

Summary of clinical uses

At present all modes of liquid ventilation remain experimental. PLV has been used in only a small number of patients worldwide. The technique is currently only employed in specialist centers usually as part of a randomized controlled trial. With the accumulation of evidence supporting the safety and efficacy of liquid ventilation it is probable that it will become an important technology for the future treatment of patients in respiratory distress.

Potential uses

Diving

In diving, the pressure inside the lungs must effectively equal the pressure outside the body, otherwise the lungs collapse. Mathematically speaking, if the diver is f feet (or m meters) deep, and the air pressure at the water surface is p bar (usually p = 1, but less at high-altitude lakes such as Lake Titicaca), he must breathe fluid at a pressure of f/33+p = m/10+p bar.

Since external and internal pressures must be equal, the required gas pressure increases with depth to match the increased external water pressure, rising to around 13 bar at 400 feet (120m), and around 500 bar on the oceans' abyssal plains. These high pressures may have adverse effects on the body, especially when quickly released (as in a too-rapid return to the surface), including air emboli and decompression sickness (colloquially known as "the bends"). (Diving mammals, as well as free-diving humans who dive to great depths on a single breath, have little or no problem with decompression sickness despite their rapid return to the surface, since a single breath of gas does not contain enough total nitrogen to cause tissue bubbles on decompression. In very deep-diving mammals and deep free-diving humans, the lungs almost completely collapse).

One solution is a rigid articulated diving suit, but these are bulky and clumsy. A more moderate option to deal with narcosis is to breathe heliox or trimix, in which some or all of the nitrogen is replaced by helium. However, this option does not deal with the problem of bubbles and decompression sickness, because helium dissolves in tissues and causes bubbles when pressures are released, just like nitrogen does.

Liquid breathing provides a third option. With liquid in the lungs, the pressure within the diver's lungs could accommodate changes in the pressure of the surrounding water without the huge gas partial pressure exposures required when the lungs are filled with gas. Liquid breathing would not result in the saturation of body tissues with high pressure nitrogen or helium that occurs with the use of non-liquids, thus would reduce or remove the need for slow decompression. (This technology was dramatized in James Cameron's 1989 film The Abyss.)

A significant problem, however, arises from the high viscosity of the liquid and the corresponding reduction in its ability to remove CO₂. All uses of liquid breathing for diving must involve total liquid ventilation (see above). Total liquid ventilation, however, has difficulty moving enough liquid to carry away CO₂, because no matter how great the total pressure is, the amount of partial CO₂ gas pressure available to dissolve CO₂ into the breathing liquid can never be much more than the pressure at which CO₂ exists in the blood (about 40 mm of mercury (Torr)).

At these pressures, most fluorocarbon liquids require about 70 mL/kg minute-ventilation volumes of liquid (about 5 L/min for a 70 kg adult) to remove enough CO₂ for normal resting metabolism.^[10] This is a great deal of fluid to move, particularly as liquids are generally more viscous than gases, (for example water is about 56 times the viscosity of air). Any increase in the diver's metabolic activity also increases CO₂ production and the breathing rate, which is already at the limits of realistic flow rates in liquid breathing.^[11][12] It seems unlikely that a person would move 10 liters/min of fluorocarbon liquid without assistance from a mechanical ventilator, so "free breathing" may be unlikely.

Medical treatment

The first medical use of liquid breathing was treatment of premature babies and adults with acute respiratory distress syndrome (ARDS) in the 1990s. Liquid breathing was used in clinical trials after the development by Alliance Pharmaceuticals of the fluorochemical perfluorooctyl bromide, or perflubron for short. Useful as an emulsified blood substitute and for liquid ventilation, perflubron (under Alliance Pharmaceutical's brand name LiquiVent) is administered via an endotracheal tube (ETT) directly into the lungs of patients with acute respiratory failure (caused by infection, severe burns, inhalation of toxic substances, and premature birth), whose alveoli have collapsed. Once instilled, perflubron acts in two principal ways to improve gas exchange in the lung. Firstly, the gas-liquid interface present in the ordinary lung is replaced with a liquid-liquid interface allowing for more efficient transfer of Oxygen and Carbon dioxide. Furthermore, a liquid positive end expiratory pressure or "PEEP" is exerted which forces open previously closed regions of the lung creating a more homogenously respiring lung.

In 1996 Mike Darwin and Dr. Steven B. Harris proposed using cold liquid ventilation with perfluorocarbon to quickly lower the body temperature of victims of cardiac arrest and other brain trauma to allow the brain to better recover.^[13] The technology came to be called gas/liquid ventilation (GLV), and was shown able to achieve a cooling rate of 0.5 degrees Celsius per minute in large animals.^[14] It has not yet been tried in humans.

Pediatric medicine

The most promising area for the use of liquid ventilation is in the field of pediatric medicine. Current methods of positive-pressure ventilation can contribute to the development of lung disease in pre-term neonates, leading to diseases such as bronchopulmonary dysplasia. Liquid ventilation removes many of the high pressure gradients responsible for this damage. Furthermore, Perfluorocarbons have been demonstrated to reduce lung inflammation, improve ventilation-perfusion mismatch and to provide a novel route for the pulmonary administration of drugs. Clinical trials with premature infants, children and adults were conducted. Since the safety of the procedure and the effectiveness were apparent from an early stage, the US Food and Drug Administration (FDA) gave the product "fast track" status (meaning an accelerated review of the product, designed to get it to the public as quickly as is safely possible) due to its life-saving potential. Clinical trials showed that using perflubron with ordinary ventilators improved outcomes as much as using high frequency oscillating ventilation (HFOV). But because perflubron was not better than HFOV, the FDA did not approve perflubron, and Alliance is no longer pursuing the partial liquid ventilation application. Whether perflubron would improve outcomes when used with HFOV remains an open question.

Space travel

Liquid immersion provides a way to reduce the physical stress of G forces. Forces applied to fluids are distributed as omnidirectional pressures. Because liquids are (virtually) incompressible, they do not change density under high acceleration such as performed in aerial maneuvers or space travel. A person immersed in liquid of the same density as tissue has acceleration forces distributed around the body, rather than applied at a single point such as a seat or harness straps. This principle is used in a new type of G-suit called the Libelle G-suit, which allows aircraft pilots to remain conscious and functioning at more than 10 G acceleration by surrounding them with water in a rigid suit.

Acceleration protection by liquid immersion is limited by the differential density of body tissues and immersion fluid, limiting the utility of this method to about 15 to 20 G^[15] Extending acceleration protection beyond 20 G requires filling the lungs with fluid of density similar to water. An astronaut totally immersed in liquid, with liquid inside all body cavities, will feel little effect from extreme G forces because the forces on a liquid are distributed equally, and in all directions simultaneously. However effects will be felt because of density differences between different body tissues, so an upper acceleration limit still exists.

Around 1970, liquid breathing found its way into television, in alien spacesuits in the Gerry Anderson UFO series, which enabled a spaceman to withstand extreme acceleration forces.

Author Joe Haldeman, in his science fiction novel The Forever War, describes fluid being introduced into all 7 natural orifices in the human body, and one surgically-added connection, through which the thoracic cavity would be filled and drained. In such a situation, the fluid in the lungs would have to be pumped in and out to provide an inspiration/expiration cycle (total liquid ventilation). Alternatively blood could be oxygenated extracorporeally while lungs remained full of passive fluid, although this is not really liquid breathing.

Liquid breathing for acceleration protection may never be practical because of the difficulty of finding a suitable breathing medium of similar density to water that is compatible with lung tissue. Perfluorocarbon fluids are twice as dense as water, hence unsuitable for this application.

http://en.wikipedia.org/wiki/Liquid_breathing

Earth's atmosphere

he Earth's atmosphere is a layer of gases surrounding the planet Earth and retained by the Earth's gravity. It contains roughly (by molar content/volume) 78.08% nitrogen, 20.95% oxygen, 0.93% argon, 0.038% carbon dioxide, trace amounts of other gases, and a variable amount (average around 1%) of water vapor. This mixture of gases is commonly known as air. The atmosphere protects life on Earth by absorbing ultraviolet solar radiation and reducing temperature extremes between day and night.

There is no definite boundary between the atmosphere and outer space. It slowly becomes thinner and fades into space. Three quarters of the atmosphere's mass is within 11 km of the planetary surface. In the United States, people who travel above an altitude of 80.5 km (50 statute miles) are designated astronauts. An altitude of 120 km (~75 miles or 400,000 ft) marks the boundary where atmospheric effects become noticeable during re-entry. The Kármán line, at 100 km (62 miles or 328,000 ft), is also frequently regarded as the boundary between atmosphere and outer space.

Air Conditioning through the ages

Air conditioning

Origins date back to 2nd Century China and Ancient Romans

The term air conditioning most commonly refers to the cooling and dehumidification of indoor air for thermal comfort. In a broader sense, the term can refer to any form of cooling, heating, ventilation or disinfection that modifies the condition of air.^[1] An air conditioner (AC or A/C in North American English, aircon in British and Australian English) is an appliance, system, or mechanism designed to stabilise the air temperature and humidity within an area (used for cooling as well as heating depending on the air properties at a given time) , typically using a refrigeration cycle but sometimes using evaporation, most commonly for comfort cooling in buildings and transportation vehicles.

The concept of air conditioning is known to have been applied in Ancient Rome, where aqueduct water was circulated through the walls of certain houses to cool them. Similar techniques in medieval Persia involved the use of cisterns and wind towers to cool buildings during the hot season. Modern air conditioning emerged from advances in chemistry during the 19th century, and the first large-scale electrical air conditioning was invented and used in 1902 by Willis Haviland Carrier.

History

While moving heat via machinery to provide air conditioning is a relatively modern invention, the cooling of buildings is not. The ancient Romans were known to circulate aqueduct water through the walls of certain houses to cool them. As this sort of water usage was expensive, generally only the wealthy could afford such a luxury.

The 2nd century Chinese inventor Ding Huan (fl. 180) of the Han Dynasty invented a rotary fan for air conditioning, with seven wheels 3 m (10 ft) in diameter and manually powered.^[2] In 747, Emperor Xuanzong (r. 712–762) of the Tang Dynasty (618–907) had the Cool Hall (Liang Tian) built in the imperial palace, which the Tang Yulin describes as having water-powered fan wheels for air conditioning as well as rising jet streams of water from fountains.^[3] During the subsequent Song Dynasty (960–1279), written sources mentioned the air conditioning rotary fan as even more widely used.^[4]

Medieval Persia had buildings that used cisterns and wind towers to cool buildings during the hot season: cisterns (large open pools in a central courtyards, not underground tanks) collected rain water; wind towers had windows that could catch wind and internal vanes to direct the airflow down into the building, usually over the cistern and out through a downwind cooling tower.^[5] Cistern water evaporated, cooling the air in the building.

Ventilators were invented in medieval Egypt and were widely used in many houses throughout Cairo during the Middle Ages. These ventillators were later described in detail by Abd al-Latif al-Baghdadi in 1200, who reported that almost every house in Cairo has a ventillator, and that they cost anywhere from 1 to 500 dinars depending on their sizes and shapes. Most ventillators in the city were oriented towards the Qibla, as was the city in general.^[6]

In 1820, British scientist and inventor Michael Faraday discovered that compressing and liquefying ammonia could chill air when the liquefied ammonia was allowed to evaporate. In 1842, Florida physician John Gorrie used compressor technology to create ice, which he used to cool air for his patients in his hospital in Apalachicola, Florida.^[7] He hoped eventually to use his ice-making machine to regulate the temperature of buildings. He even envisioned centralized air conditioning that could cool entire cities.^[8] Though his prototype leaked and performed irregularly, Gorrie was granted a patent in 1851 for his ice-making machine. His hopes for its success vanished soon afterwards when his chief financial backer died; Gorrie did not get the money he needed to develop the machine. According to his biographer Vivian M. Sherlock, he blamed the "Ice King," Frederic Tudor, for his failure, suspecting that Tudor had launched a smear campaign against his invention. Dr. Gorrie died impoverished in 1855 and the idea of air conditioning faded away for 50 years.

Early commercial applications of air conditioning were manufactured to cool air for industrial processing rather than personal comfort. In 1902 the first modern electrical air conditioning was invented by Willis Haviland Carrier. Designed to improve manufacturing process control in a printing plant, his invention controlled not only temperature but also humidity. The low heat and humidity were to help maintain consistent paper dimensions and ink alignment. Later Carrier's technology was applied to increase productivity in the workplace, and The Carrier Air Conditioning Company of America was formed to meet rising demand. Over time air conditioning came to be used to improve comfort in homes and automobiles. Residential sales expanded dramatically in the 1950s.

In 1906, Stuart W. Cramer of Charlotte, North Carolina, USA, was exploring ways to add moisture to the air in his textile mill. Cramer coined the term "air conditioning," using it in a patent claim he filed that year as an analogue to "water conditioning", then a well-known process for making textiles easier to process. He combined moisture with ventilation to "condition" and change the air in the factories, controlling the humidity so necessary in textile plants. Willis Carrier adopted the term and incorporated it into the name of his company. This evaporation of water in air, to provide a cooling effect, is now known as evaporative cooling.

The first air conditioners and refrigerators employed toxic or flammable gases like ammonia, methyl chloride, and propane which could result in fatal accidents when they leaked. Thomas Midgley, Jr. created the first chlorofluorocarbon gas, Freon, in 1928. The refrigerant was much safer for humans but was later found to be harmful to the atmosphere's ozone layer. Freon is a trademark name of DuPont for any Chlorofluorocarbon (CFC), Hydrogenated CFC (HCFC), or Hydrofluorocarbon (HFC) refrigerant, the name of each including a number indicating molecular composition (R-11, R-12, R-22, R-134). The blend most used in direct-expansion comfort cooling is an HCFC known as R-22. It is to be phased out for use in new equipment by 2010 and completely discontinued by 2020. R-11 and R-12 are no longer manufactured in the US, the only source for purchase being the cleaned and purified gas recovered from other air conditioner systems. Several non-ozone depleting refrigerants have been developed as alternatives, including R-410A, known by the brand name Puron.

Innovation in air conditioning technologies continue, with much recent emphasis placed on energy efficiency and improving indoor air quality. As an alternative to conventional refrigerants, natural alternatives like CO₂ (R-744) have been proposed.^[9]

Airborne bacteria may play large role in precipitation

A Montana State University professor and his colleagues have found evidence suggesting that airborne bacteria are globally distributed in the atmosphere and may play a large role in the cycle of precipitation.

The research of David Sands, MSU professor of plant sciences and plant pathology, along with his colleagues Christine Foreman, an MSU professor of land resources and environmental sciences, Brent Christner from Louisiana State University and Cindy Morris, will be published today in the journal "Science."

These research findings could potentially supply knowledge that could help reduce drought from Montana to Africa, Sands said.

Sands, Foreman, Morris, and Christner -- who did post-doctorate work at MSU -- examined precipitation from locations as close as Montana and as far away as Russia to show that the most active ice nuclei are actually biological in origin. Nuclei are the seeds around which ice is formed. Snow and most rain begins with the formation of ice in clouds. Dust and soot can also serve as ice nuclei. But biological ice nuclei are different from dust and soot nuclei because only these biological nuclei can cause freezing at warmer temperatures.

Biological precipitation, or the "bio-precipitation" cycle, as Sands calls it, basically is this: bacteria form little groups on the surface of plants. Wind then sweeps the bacteria into the atmosphere, and ice crystals form around them. Water clumps on to the crystals, making them bigger and bigger. The ice crystals turn into rain and fall to the ground. When precipitation occurs, then, the bacteria have the opportunity to make it back down to the ground. If even one bacterium lands on a plant, it can multiply and form groups, thus causing the cycle to repeat itself.

"We think if (the bacteria) couldn't cause ice to form, they couldn't get back down to the ground," Sands said. "As long as it rains, the bacteria grow."

The team's work is far-reaching. Sands and his colleagues have found the bacteria all over the world, including Montana, California, the eastern U.S., Australia, South Africa, Morocco, France and Russia.

The team's research also shows that most known ice-nucleating bacteria are associated with plants and some are capable of causing disease.

"Bacteria have probably been around for a million years," Sands said. "They live on the surface of plants, and may occasionally cause plant disease. But their role in rain-making may be more important."

Indeed, the implications of a relationship between rain and bacteria could be enormous, though they are yet to be proven, Sands said.

For example, a reduced amount of bacteria on crops could affect the climate. Because of the bio-precipitation cycle, overgrazing in a dry year could actually decrease rainfall, which could then make the next year even dryer.

"Drought could be less of a problem once we understand all of this," Sands said.

Sands, who earned a doctorate in pathology and bacteriology from the University of California-Berkeley, proposed the concept of bio-precipitation approximately 25 years ago, but few people believed him.

Since that time, he said, better tools have changed the research climate, because new DNA technology allows researchers to distinguish the bacteria, and giant computers allow people to do meteorological studies with satellites.

"It's fun to see something come out after 25 years," Sands said, "particularly when we knew back then it was true."

More studies must be done, though, because questions remain. For example, since the bacteria do not grow above 84 degrees, precipitation could be affected if the world's weather creeps up and reaches a cut-off point, Sands said. The researchers are also examining the bacteria to find out if they vary by region.

At any rate, a diverse group of people should be interested in the research, because bio-precipitation could affect many things.

"I want people to be fascinated by the interconnection of things going on in the environment," Sands said. "It's all interconnected."

Twister Power!!!!

Storm Prediction Center.
Predicting and informing people of incomings storms, and tornados.
http://www.spc.noaa.gov/


The Tornado Timeline covers major moments in the history of Tornadoes in American History.
http://www.tornadoarchive.com/T imeline.aspx/


How A tornado is for.



Video of random tornados.
http://www.youtube.com/watch?v=UVppfnXtPZ4&feature=related/

Tornados of 2007. Just a few videos.(theres more)
http://www.youtube.com/watch?v=b0wQdRcgSoI
http://www.youtube.com/watch?v=DNL7ASvl4k4
http://www.youtube.com/watch?v=kEUXr6FMtWk


and yes even movies of tornado's. and the hight light a flying cow.

Tornado Alley

Tornadoes can occur almost anywhere in the world, but the United States is the country with the highest frequency of tornadoes. Each year there are about 1,200 tornadoes in the United States, causing about 65 fatalities and 1,500 injuries nationwide.

Tornadoes becoming more frequent in Missouri

JOPLIN, MO. (AP) -- Tornadoes in Missouri are on the rise, even if experts can't say for certain why.

National Weather Service records going back to 1956 show an average of 30 tornadoes a year in Missouri.

But the totals have been higher in recent years.

Last year the weather service counted 42 confirmed twisters in Missouri.

There have been 35 logged so far this year.

The state record was 102 tornadoes in 2006.

State climatologist Pat Guinan said it's difficult to say if climate change is linked to increasing tornado numbers since records go back only to the 1950s. The numbers could also be linked to better detection and verification.

Missouri observes Tornado Awareness Week March 10-14.

(Copyright 2008 by The Associated Press. All Rights Reserved.)

And to top it of, music from a Japanese band, name tornado.
http://www.youtube.com/watch?v=MDM0jU62EqM

Air Washing

http://www.interesting.vaty.net/2006/10/air-washing.html

A truly futuristic design, an Airwash washing machine should hopefully be a common fixture in all homes by 2020. Designed by two industrial design students from the National University of Singapore, the Airwash Washing Machine won Electrolux's Design Lab Award.

Inspired by the waterfall, nature's negative ion generator, this washing machine does not use any water or detergent. It utilizes negative ions, compressed air and deodorants to clean clothes. The atmospheric air and negative ions - a natural cleansing agent - fight the dirt and bacteria. The machine can be placed anywhere at home and not necessarily in the laundry area.

Sigh! Do we really have to wait for 14 years to get our hands on this miracle washer?

Air pollution can prevent rainfall

http://www.scienceblog.com/community/older/2000/A/200000005.html

Air pollution can prevent rainfall, reported in the 10 March 2000 issue of Science

Washington D.C. - Urban and industrial air pollution can stifle rain and snowfall, a new study shows, because the pollution particles prevent cloud water from condensing into raindrops and snowflakes. These findings are reported in the 10 March issue of Science.

The new study, by Daniel Rosenfeld, of the Hebrew University of Jerusalem, presents satellite images and measurements of "pollution tracks" downstream from major urban areas and air pollution sources such as power plants, lead smelters, and oil refineries. The tracks consist of polluted clouds that have shut off virtually all precipitation because they contain abnormally small water droplets.

The droplets' small size is caused by pollution particles that act as "seeding" sites around which cloud moisture condenses. Approximately one million small droplets must collide and coalesce in order to make a precipitation-sized drop-that is, one large enough to fall below the cloud base and reach the ground before evaporating. In polluted clouds, there are too many small droplets and not enough larger ones. These small droplets float in the air with low probability of bumping into each other and merging into raindrops. The smaller droplets are also slower to freeze into ice crystals, resulting in less sleet and snowfall.

Because urban and industrial air pollution is a significant problem in many regions of the world, Rosenfeld's findings suggest that human activity may be affecting rainfall patterns on a global scale.

These data are the first direct evidence of how urban and industrial pollution affects rainfall levels, a question scientists have debated for several decades. In fact, some previous studies have concluded that air pollution might increase rainfall, but the debate has continued due to a lack of convincing data.

"In the past, scientists had to collect information by poking little holes in clouds from airplanes, or using statistics about rainfall patterns because you can't replicate rain-clouds in the lab. Now, new satellite instruments allow us to have a comprehensive look at the problem. For the first time, we can measure cloud precipitation and microstructure simultaneously over large areas," Rosenfeld said.

In his Science paper, Rosenfeld presents the first images of pollution tracks over land. The images, taken over regions in Turkey, Canada, and Australia, all contain known sources of industrial or urban air pollution. The tracks stream away from these pollution sources in long narrow plumes.

Rosenfeld took yet a closer look at the pollution tracks in Australia, where the plumes were particularly striking. Further measurements from a bevy of satellite instruments showed that precipitation of both raindrops and ice crystals-which was occurring in the unpolluted clouds-was practically shut off in the clouds within the pollution tracks. However, the total amount of moisture in the polluted clouds was sufficient to produce rain and snow.

Rosenfeld also notes that in other parts of the world air pollution is more widespread and not as easy to distinguish as it is against the relatively clean Australian atmosphere. Thus the well-defined tracks identified in the study "serve as a Rosetta stone for the potential impact of more widely distributed aerosol pollution on clouds," writes Owen Toon, of the University of Colorado at Boulder, in a related commentary article.

Baylor Institute for Air Science

http://www.baylor.edu/bias/

BIAS for Excellence In Environmental Research, Education and Public Service

The mission of the Baylor Institute for Air Science (BIAS) is to foster stewardship of the environment through research, public service and the education of a new generation of scientist-pilots dedicated to environmental research.

The course of study is highly interdisciplinary in nature. Professors from other disciplines collaborate in providing a unique program called the Scientist-Pilot program. This program involves research and development in monitoring air quality with instrumented aircraft and alternative aviation fuels. Scientists, government agencies, and private sectors partner in the investigations. The BIAS research facilities include aircraft and engine test stands and the Renewable Aviation Fuel Development Center (RAFDC).

BIAS interacts with government and university officials world-wide regarding programs that use biomass fuels in aircraft and air quality monitoring programs using instrumented aircraft. BIAS conducts conferences, seminars and demonstrations on critical issues of air pollution, the development of renewable transportation fuels and the imperatives concerning environmental stewardship.

History of Air Pollution

http://www.ace.mmu.ac.uk/eae/Air_Quality/Older/History.html

Air pollution, particularly in cities, is certainly not a new problem. Back in the Middle Ages the use of coal in cities such as London was beginning to escalate. The problems of poor urban air quality even as early as the end of the 16^th century are well documented.

In the UK the Industrial Revolution during the 18^th and 19^th centuries was based on the use of coal. Industries were often located in towns and cities, and together with the burning of coal in homes for domestic heat, urban air pollution levels often reached very high levels. During foggy conditions, pollution levels escalated and urban smogs (smoke and fog) were formed. These often brought cities to a halt, disrupting traffic but more dangerously causing death rates to dramatically rise. The effects of this pollution on buildings and vegetation also became obvious. The 1875 Public Health Act contained a smoke abatement section to try and reduce smoke pollution in urban areas.

During the first part of the 20^th century, tighter industrial controls lead to a reduction in smog pollution in urban areas. The 1926 Smoke Abatement Act was aimed at reducing smoke emissions from industrial sources, but despite the declining importance of coal as a domestic fuel, pollution from domestic sources remained significant.

The Great London Smog of 1952, which resulted in around 4,000 extra deaths in the city, led to the introduction of the Clean Air Acts of 1956 and 1968. These introduced smokeless zones in urban areas, with a tall chimney policy to help disperse industrial air pollutants away from built up areas into the atmosphere.

Following the Clean Air Acts, air quality improvements continued throughout the 1970s. Further regulations were introduced through the 1974 Control of Air Pollution Act. This included regulations for the composition of motor fuel and limits for the sulphur content of industrial fuel oil.

However, during the 1980s the number of motor vehicles in urban areas steadily increased and air quality problems associated with motor vehicles became more prevalent. In the early 1980s, the main interest was the effects of lead pollution on human health, but by the late 1980s and early 1990s, the effects of other motor vehicle pollutants became a major concern. The 1990s have seen the occurrence of wintertime and summertime smogs. These are not caused by smoke and sulphur dioxide pollution but by chemical reactions occurring between motor vehicle pollutants and sunlight. These are known as ‘photochemical smogs’.

In 1995, the Government passed its Environment Act, requiring the publication of a National Air Quality Strategy to set standards for the regulation of the most common air pollutants. Published in 1997, the National Air Quality Strategy has set commitments for local authorities to achieve new air quality objectives throughout the UK by 2005. It is reviewed periodically.

The Air Purifiers and Air Purifier Technology Today

http://www.airpurifiers.com/today.htm

The air purifiers have proved to be a very useful tool in homes, hospitals, schools, and offices around the world over the last fifty years. It has helped millions of people who suffer from Asthma, Multiple Chemical Sensitivity (MCS), Environmental Tobacco Smoke (ETS), noxious gases, foul odors, and many other allergens.

For the last twenty years or so, environmental tobacco smoke (ETS) has been proven to cause a great deal of health complications. Today you can find air purifiers that can help to decrease and completely remove ETS from the air. Many of these systems are found in night clubs, bars, and restaurants due to the high volume of smokers. There are now smaller purifying units that fit comfortably into your household that can clear the air of hazardous tobacco smoke.

ETS contains very harmful particles along with hazardous to your health gaseous compounds such as hydrogen cyanide, nitrogen oxides, carbon monoxide, and carbon dioxide. Along with all of those, ETS also contains a grand amount of volatile compounds like ethane, propene, formaldehyde acetaldehyde, acetone, benzene, and acrolein. These are what cause the smell and irritation from tobacco smoke.

The systems that are designed for ETS have the effectiveness to take in particles of .01 microns in diameter. They also have a large capacity for holding such tiny particles and they also have an expansive spectrum gas filter. These types of air purifiers also have a very high air delivery due to the fact that rooms that contain ETS must be cleaned every few hours to ensure that the air is not harmful.

The development of air purifiers that could rid the air of chemicals came about during war times. Chemical warfare was a great fear and what better way to combat it than to design an air filter that could filter out all of the harmful chemicals in the air that the military breathed in.

MCS is the result of those who are very sensitive to chemicals such as carpets, additives to foods, household cleaners, fuel, fabrics, building materials, pesticides, and perfumes. MCS can result because the person has had an allergic reaction to a specific chemical or to a wide range of chemicals. Many of the symptoms are difficulty breathing, burning irritated eyes, migraines, nausea, aching joints, fatigue, or trouble sleeping. MCS is commonly found in middle aged women. Due to the chemicals that are in these types of products there are air purifiers that can reduce these effects and clear the air of the harmful particles, making it much easier for MCS sufferers to cope.

When it comes down to finding air purifiers on the market to help combat MCS, you will most likely find them very few and far between. It's not that there are none out there, it's just that the ones that are out there, can't effectively filter out gases and chemicals because the gas filter is just too small to work efficiently. More and more air purifiers are being designed with granular activated carbon filters that help to increase the air purification process of harmful chemical gases and odors. Some air purifiers may have carbon filters, but they will not remove all of the chemical gases. You should look for a unit that has an activated carbon filter to filter out the volatile organic compounds as well as the chemicals that contaminate the air causing some people to have a reaction.

Allergies and asthma are another major reason to look for an air purifier. From the start it seems as if this was one of the main reasons to create such a contraption as the air purifiers. Those who suffer from asthma tend to be affected by particles in the air. The same is true for anyone suffering from allergies. Allergens such as pet dander, dust mites, and pollen travel through the air to the sufferers lungs as they breath in. Indoor allergens tend to affect people more than outdoor ones because we tend to spend about ninety percent of our time indoors and the remaining ten percent outdoors.

Air purifiers can now combat 99.7 percent of all indoor allergens using a HEPA filter and a pre filter. The pre filter traps the larger particles and the HEPA filter takes in the remaining particles making the air much cleaner and easier to breath.

All in all, today's air purifiers have come a long way from what they were fifty years ago.