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Weather modification is the act of intentionally manipulating or altering the weather. The most common form of weather modification is cloud seeding, which increases rainfall or snowfall, usually for the purpose of increasing the local water supply. [1] Weather modification can also have the goal of preventing damaging weather, such as hail or hurricanes, from occurring; or of provoking damaging weather against an enemy, as a tactic of military or economic warfare like Operation Popeye, where clouds were seeded to prolong the monsoon in Vietnam. Weather modification in warfare has been banned by the United Nations under the Environmental Modification Convention.
A popular belief in Northern Europe was that shooting prevents hail, which thus caused many agricultural towns to fire cannons without ammunition. Veterans of the Seven Years' War, Napoleonic wars, and the American Civil War reported that rain fell after every large battle. After their stories were collected in War and Weather, the United States Department of War in the late 19th century purchased $9,000 of gunpowder and explosives to detonate them in Texas, in hopes of condensing water vapor into rain. The results of the test, supervised by Robert Dyrenforth, were inconclusive. [2]
Wilhelm Reich performed cloudbusting experiments in the 1950s, the results of which are controversial and were not widely accepted by mainstream science.
In November 1954 the Thailand Royal Rainmaking Project (Thai: โครงการฝนหลวง) was initiated by King Bhumibol Adulyadej. He discovered that many areas faced the problem of drought. Over 82 percent of Thai agricultural land relied on rainfall. Thai farmers were not able to grow crops for lack of water. The royal rainmaking project debuted on 20 July 1969 at his behest, when the first rainmaking attempt was made at Khao Yai National Park. Dry ice flakes were scattered over clouds. Reportedly, some rainfall resulted. In 1971, the government established the Artificial Rainmaking Research and Development Project within the Thai Ministry of Agriculture and Cooperatives. [3] [ circular reference ]
In January 2011, several newspapers and magazines, including the UK's Sunday Times and Arabian Business, reported that scientists backed by the government of Abu Dhabi, the capital of the United Arab Emirates, had created over 50 artificial rainstorms between July and August 2010 near Al Ain, a city which lies close to the country's border with Oman and is the second-largest city in the Abu Dhabi Emirate. The artificial rainstorms were said to have sometimes caused hail, gales and thunderstorms, baffling local residents. [4]
In the run up to the 2008 Beijing Olympic Games, the Chinese Government said they could control precipitation to some extent and that the Games would not be hampered by bad weather conditions. For this purpose they established a government office called the Beijing Weather Modification Office, which is under the national weather control office. [5] [6]
Cloud seeding is a common technique to enhance precipitation. Cloud seeding entails spraying small particles, such as silver iodide, onto clouds to attempt to affect their development, usually with the goal of increasing precipitation. Cloud seeding only works to the extent that there is already water vapor present in the air. Critics generally contend that claimed successes occur in conditions which were going to lead to rain anyway. It is used in a variety of drought-prone countries, including the United States, China, India, and Russia. In China, there is a perceived dependency upon it in dry regions, and there is a strong suspicion it is used to "wash the air" in dry and heavily polluted places, such as Beijing. [7] In mountainous areas of the United States such as the Rocky Mountains and Sierra Nevada, [8] cloud seeding has been employed since the 1950s.
Project Cirrus was an attempt by General Electric to modify the weather which ran from 1947-1952. During that time, under the supervision of the United States Air Force, attempts were made to create snowstorms and seed hurricanes by using silver iodide. While General Electric reported positive results, they also acknowledged that their experiments were controversial. [9]
The United Arab Emirates has been cloud seeding since the 2000s and aims to increase rainfall by 15-30% per year. The materials used are potassium chloride, sodium chloride, magnesium, and other materials. [10] [11]
Not having adequate systems to handle weather modification may have disastrous consequences. "In the city of Jeddah in Western Saudi Arabia was damaged by floods in 2009 that reportedly killed more than 100 people; igniting questions of why the country doesn't have effective drainage systems in place." [11]
The U.S. National Library of Medicine notes that the silver iodide has no known "ill effects" on people, although people's "hands may have remained yellowed for weeks" after being exposed to it. [12]
Project Stormfury was an attempt to weaken tropical cyclones by flying aircraft into storms and seeding the eyewall with silver iodide. The project was run by the United States Government from 1962 to 1983. A similar project using soot was run in 1958, with inconclusive results. [13] Various methods have been proposed to reduce the harmful effects of hurricanes. Moshe Alamaro of the Massachusetts Institute of Technology [14] proposed using barges with upward-pointing jet engines to trigger smaller storms to disrupt the progress of an incoming hurricane; critics doubt the jets would be powerful enough to make any noticeable difference. [13]
Alexandre Chorin of the University of California, Berkeley, proposed dropping large amounts of environmentally friendly oils on the sea surface to prevent droplet formation. [15] Experiments by Kerry Emanuel [16] of MIT in 2002 suggested that hurricane-force winds would disrupt the oil slick, making it ineffective. [13] Other scientists disputed the factual basis of the theoretical mechanism assumed by this approach. [15]
The Florida company Dyn-O-Mat and its CEO, Peter Cordani, proposed the use of a patented product it developed, called Dyn-O-Gel, to reduce the strength of hurricanes. The substance is a polymer in powder form (a polyacrylic acid derivative) which reportedly has the ability to absorb 1,500 times its own weight in water. The theory is that the polymer is dropped into clouds to remove their moisture and force the storm to use more energy to move the heavier water drops, thus helping to dissipate the storm. When the gel reaches the ocean surface, it is reportedly dissolved. Peter Cordani teamed up with Mark Daniels and Victor Miller, the owners of a government contracting aviation firm AeroGroup which operated ex-military aircraft commercially. Using a high altitude B-57 Bomber, AeroGroup tested the substance dropping 9,000 pounds from the B-57 aircraft's large bomb bay and dispersing it into a large thunderstorm cell just off the east coast of Florida. The tests were documented on film and made international news showing the storms were successfully removed on monitored Doppler radar. In 2003, the program was shut down because of political pressure through NOAA. [17] Numerical simulations performed by NOAA showed however that it would not be a practical solution for large systems like a tropical cyclone. [18]
Hail cannons have been used by some farmers since the 19th century in an attempt to ward off hail, but there is no reliable scientific evidence to confirm their effectiveness. Another new anti-hurricane technology [19] is a method for the reduction of tropical cyclones' destructive force – pumping sea water into and diffusing it in the wind at the bottom of such tropical cyclones in its eye wall.
NOAA published a page addressing various ideas in regard to tropical cyclone manipulation.
In 2007, "How to stop a hurricane" [20] explored various ideas such as:
Researchers from NOAA's hurricane research division addressed hurricane control based ideas. [21]
Later ideas (2017) include laser inversion along the same lines as laser cooling (normally used at cryogenic temperatures) but intended to cool the top 1mm of water. If enough power were to be used then it may be enough, combined with computer modelling, to form an interference pattern able to inhibit a hurricane or significantly reduce its strength by depriving it of heat energy. [22] [23]
Other proposals for hurricane modification include the construction of a large array of offshore wind turbines along the East Coast of the United States. Such turbines would have the dual purpose of generating plentiful energy whilst also reducing the power of oncoming hurricanes before they make landfall. [24]
Operation Popeye was a highly classified operation run by the US military from 1967-1972. [25] The purpose was to prolong the monsoon in Southeast Asia. The overwhelming precipitation successfully disrupted the tactical logistics of the Vietnamese army. Operation Popeye is believed as the first successful practice of weather modification technology in warfare. After it was unveiled, weather modification in warfare was banned by the Environmental Modification Convention (ENMOD). [26]
In "Benign Weather Modification" published in March 1997, Air Force Major Barry B. Coble superficially documents the existence of weather modification science where he traces the developments that have occurred, notably, in the hands of the Pentagon and CIA's staunchest ideological enemies.
In the 1990s a directive from the chief of staff of the Air Force Ronald R. Fogleman was issued to examine the concepts, capabilities, and technologies the United States would require to remain the dominant air and space force in the future.
In 1975, the US and Canada entered into an agreement under the auspices of the United Nations for the exchange of information on weather modification activity. [29]
Weather modification, particularly hostile weather warfare, was addressed by the "United Nations General Assembly Resolution 31/72, TIAS 9614 Convention [30] on the Prohibition of Military or Any Other Hostile Use of Environmental Modification Techniques." The Convention was signed in Geneva on May 18, 1977; entered into force on October 5, 1978; ratified by U.S. President Jimmy Carter on December 13, 1979; and the U.S. ratification deposited in New York on January 17, 1980. [31]
In the US, the National Oceanic and Atmospheric Administration keeps records of weather modification projects on behalf of the Secretary of Commerce, under the authority of Public Law 92-205, 15 USC § 330B, enacted in 1971. [32]
U.S. Senate Bill 517 [33] and U.S. House Bill 2995 [34] were two bills proposed in 2005 that would have expanded experimental weather modification, to establish a Weather Modification Operations and Research Board, and implemented a national weather modification policy. Neither was made into law.
Senate Bill 1807 and House Bill 3445, identical bills introduced July 17, 2007, proposed to established a Weather Mitigation Advisory and Research Board to fund weather modification research [35] [36]
Tennessee bill HB 2063/SB 2691 was signed into law on April 11, 2024. This bill bans the "intentional injection, release, or dispersion" of chemicals within Tennessee "with the express purpose of affecting temperature, weather, or the intensity of the sunlight." [37] [38]
The text of the bill doesn't explicitly reference the chemtrail conspiracy theory, but the sponsor of the bill, Sen. Steve Southerland said that it is one of the intended targets of the bill. [39]
Magical and religious practices to control the weather are attested in a variety of cultures. In ancient India, it is said that yajna or Vedic rituals of chanting mantras and offerings were performed by rishis to bring sudden bursts of rainfall in rain starved regions. Some Indigenous Americans, like some Europeans, had rituals which they believed could induce rain. The Finnish people, on the other hand, were believed by others to be able to control the weather. As a result, Vikings refused to take Finns on their oceangoing raids. Remnants of this superstition lasted into the twentieth century, with some ship crews being reluctant to accept Finnish sailors.[ citation needed ]
The early modern era saw people observe that during battles the firing of cannons and other firearms often initiated precipitation.
In Greek mythology, Iphigenia was offered as a human sacrifice to appease the wrath of the goddess Artemis, who had becalmed the Achaean fleet at Aulis at the beginning of the Trojan War. In Homer's Odyssey , Aeolus, keeper of the winds, bestowed Odysseus and his crew with a gift of the four winds in a bag. However, the sailors opened the bag while Odysseus slept, looking for booty (money), and as a result, were blown off course by the resulting gale. [40] In ancient Rome, the lapis manalis was a sacred stone kept outside the walls of Rome in a temple of Mars. When Rome suffered from drought, the stone was dragged into the city. [41] The Berwick witches of Scotland were found guilty of using black magic to summon storms to murder King James VI of Scotland by seeking to sink the ship upon which he travelled. [42] Scandinavian witches allegedly claimed to sell the wind in bags or magically confined into wooden staves; they sold the bags to seamen who could release them when becalmed. [43] In various towns of Navarre, prayers petitioned Saint Peter to grant rain in times of drought. If the rain was not forthcoming, the statue of St Peter was removed from the church and tossed into a river.
In the Hebrew Bible, it is recorded that Elijah in the way of judgement, told King Ahab that neither dew nor rain would fall until Elijah called for it. [44] It is further recorded that the ensuing drought lasted for a period of 3.5 years at which time Elijah called the rains to come again and the land was restored. [45] The New Testament records Jesus Christ controlling a storm by speaking to it. [46]
In Islam, Salat Al-Istisqa’ (Prayer for Rain) is taken as a recourse when seeking rain from God during times of drought. [47]
Weather modification, along with climate engineering, is a recurring theme in conspiracy theories. The chemtrail conspiracy theory supposes that jet contrails are chemically altered to modify the weather and other phenomena. Other theories attempt to implicate scientific infrastructure such as the High-frequency Active Auroral Research Program. [48]
Frank Herbert's Dune series features weather control technology, mainly in the planets of Arrakis, where the technology is used to assure for privacy from observation and in order to hide from the Imperium their true population and their plans to terraform the planet, and in Chapterhouse, where the Bene Gesserit intend to turn the planet into a desert.
The ability to manipulate the weather has become a common superpower in superhero fiction. A notable example is the Marvel Comics character Storm.
In the children's book Cloudy with a Chance of Meatballs, the fictional town of Chewandswallow has weather that rains down food instead of actual rain or snow until it got too extreme and made the civilians move to a different town. This was adapted into a movie where Flint Lockwood, the town's outcast and scientist, has created a machine that converts water from the clouds into food.
In meteorology, a cyclone is a large air mass that rotates around a strong center of low atmospheric pressure, counterclockwise in the Northern Hemisphere and clockwise in the Southern Hemisphere as viewed from above. Cyclones are characterized by inward-spiraling winds that rotate about a zone of low pressure. The largest low-pressure systems are polar vortices and extratropical cyclones of the largest scale. Warm-core cyclones such as tropical cyclones and subtropical cyclones also lie within the synoptic scale. Mesocyclones, tornadoes, and dust devils lie within the smaller mesoscale.
A storm is any disturbed state of the natural environment or the atmosphere of an astronomical body. It may be marked by significant disruptions to normal conditions such as strong wind, tornadoes, hail, thunder and lightning, heavy precipitation, heavy freezing rain, strong winds, wind transporting some substance through the atmosphere such as in a dust storm, among other forms of severe weather.
The timeline of meteorology contains events of scientific and technological advancements in the area of atmospheric sciences. The most notable advancements in observational meteorology, weather forecasting, climatology, atmospheric chemistry, and atmospheric physics are listed chronologically. Some historical weather events are included that mark time periods where advancements were made, or even that sparked policy change.
In meteorology, precipitation is any product of the condensation of atmospheric water vapor that falls from clouds due to gravitational pull. The main forms of precipitation include drizzle, rain, sleet, snow, ice pellets, graupel and hail. Precipitation occurs when a portion of the atmosphere becomes saturated with water vapor, so that the water condenses and "precipitates" or falls. Thus, fog and mist are not precipitation but colloids, because the water vapor does not condense sufficiently to precipitate. Two processes, possibly acting together, can lead to air becoming saturated: cooling the air or adding water vapor to the air. Precipitation forms as smaller droplets coalesce via collision with other rain drops or ice crystals within a cloud. Short, intense periods of rain in scattered locations are called showers.
Cloud seeding is a type of weather modification that aims to change the amount or type of precipitation, mitigate hail or disperse fog. The usual objective is to increase rain or snow, either for its own sake or to prevent precipitation from occurring in days afterward.
Project Stormfury was an attempt to weaken tropical cyclones by flying aircraft into them and seeding with silver iodide. The project was run by the United States Government from 1962 to 1983. The hypothesis was that the silver iodide would cause supercooled water in the storm to freeze, disrupting the inner structure of the hurricane, and this led to seeding several Atlantic hurricanes. However, it was later shown that this hypothesis was incorrect. It was determined that most hurricanes do not contain enough supercooled water for cloud seeding to be effective. Additionally, researchers found that unseeded hurricanes often undergo the same structural changes that were expected from seeded hurricanes. This finding called Stormfury's successes into question, as the changes reported now had a natural explanation.
This is a list of meteorology topics. The terms relate to meteorology, the interdisciplinary scientific study of the atmosphere that focuses on weather processes and forecasting.
Rainmaking, also known as artificial precipitation, artificial rainfall and pluviculture, is the act of attempting to artificially induce or increase precipitation, usually to stave off drought or the wider global warming. According to the clouds' different physical properties, this can be done using airplanes or rockets to sow to the clouds with catalysts such as dry ice, silver iodide and salt powder, to make clouds rain or increase precipitation, to remove or mitigate farmland drought, to increase reservoir irrigation water or water supply capacity, to increase water levels for hydropower generation, or even to solve the global warming problem.
A mesoscale convective system (MCS) is a complex of thunderstorms that becomes organized on a scale larger than the individual thunderstorms but smaller than extratropical cyclones, and normally persists for several hours or more. A mesoscale convective system's overall cloud and precipitation pattern may be round or linear in shape, and include weather systems such as tropical cyclones, squall lines, lake-effect snow events, polar lows, and mesoscale convective complexes (MCCs), and generally forms near weather fronts. The type that forms during the warm season over land has been noted across North and South America, Europe, and Asia, with a maximum in activity noted during the late afternoon and evening hours.
The eye is a region of mostly calm weather at the center of a tropical cyclone. The eye of a storm is a roughly circular area, typically 30–65 kilometers in diameter. It is surrounded by the eyewall, a ring of towering thunderstorms where the most severe weather and highest winds of the cyclone occur. The cyclone's lowest barometric pressure occurs in the eye and can be as much as 15 percent lower than the pressure outside the storm.
A tropical cyclone is a rapidly rotating storm system with a low-pressure center, a closed low-level atmospheric circulation, strong winds, and a spiral arrangement of thunderstorms that produce heavy rain and squalls. Depending on its location and strength, a tropical cyclone is called a hurricane, typhoon, tropical storm, cyclonic storm, tropical depression, or simply cyclone. A hurricane is a strong tropical cyclone that occurs in the Atlantic Ocean or northeastern Pacific Ocean, and a typhoon occurs in the northwestern Pacific Ocean. In the Indian Ocean and South Pacific, comparable storms are referred to as "tropical cyclones". In modern times, on average around 80 to 90 named tropical cyclones form each year around the world, over half of which develop hurricane-force winds of 65 kn or more. Tropical cyclones carry heat away from the tropics and transport it towards temperate latitudes. This plays an important role in regulating global climate. Tropical cyclones can be very harmful for people.
Tropical cyclone observation has been carried out over the past couple of centuries in various ways. The passage of typhoons, hurricanes, as well as other tropical cyclones have been detected by word of mouth from sailors recently coming to port or by radio transmissions from ships at sea, from sediment deposits in near shore estuaries, to the wiping out of cities near the coastline. Since World War II, advances in technology have included using planes to survey the ocean basins, satellites to monitor the world's oceans from outer space using a variety of methods, radars to monitor their progress near the coastline, and recently the introduction of unmanned aerial vehicles to penetrate storms. Recent studies have concentrated on studying hurricane impacts lying within rocks or near shore lake sediments, which are branches of a new field known as paleotempestology. This article details the various methods employed in the creation of the hurricane database, as well as reconstructions necessary for reanalysis of past storms used in projects such as the Atlantic hurricane reanalysis.
Operation Popeye was a military cloud-seeding project carried out by the U.S. Air Force during the Vietnam War in 1967–1972. The highly classified program attempted to extend the monsoon season over specific areas of the Ho Chi Minh Trail, in order to disrupt North Vietnamese military supplies by softening road surfaces and causing landslides.
Severe weather is any dangerous meteorological phenomenon with the potential to cause damage, serious social disruption, or loss of human life. These vary depending on the latitude, altitude, topography, and atmospheric conditions. High winds, hail, excessive precipitation, and wildfires are forms and effects, as are thunderstorms, downbursts, tornadoes, waterspouts, tropical cyclones, and extratropical cyclones. Regional and seasonal phenomena include blizzards (snowstorms), ice storms, and duststorms.
Outflow, in meteorology, is air that flows outwards from a storm system. It is associated with ridging, or anticyclonic flow. In the low levels of the troposphere, outflow radiates from thunderstorms in the form of a wedge of rain-cooled air, which is visible as a thin rope-like cloud on weather satellite imagery or a fine line on weather radar imagery. For observers on the ground, a thunderstorm outflow boundary often approaches in otherwise clear skies as a low, thick cloud that brings with it a gust front.
The following outline is provided as an overview of and topical guide to the field of Meteorology.
The 1947 Florida–Georgia hurricane(Air Weather Service designation: King) was a moderate hurricane that caused catastrophic flooding in South Florida and the Everglades in mid-October 1947. The ninth tropical storm and fourth hurricane of the 1947 Atlantic hurricane season, it first developed on October 9 in the southern Caribbean Sea and hence moved north by west until a few days later it struck western Cuba. The cyclone then turned sharply to the northeast, accelerated, and strengthened to a hurricane, within 30 hours crossing the southern Florida peninsula. Across South Florida, the storm produced widespread rainfall of up to 15 inches (380 mm) and severe flooding, among the worst ever recorded in the area, that led to efforts by the United States Congress to improve drainage in the region.
In meteorology, eyewall replacement cycles, also called concentric eyewall cycles, naturally occur in intense tropical cyclones, generally with winds greater than 185 km/h (115 mph), or major hurricanes. When tropical cyclones reach this intensity, and the eyewall contracts or is already small, some of the outer rainbands may strengthen and organize into a ring of thunderstorms—a new, outer eyewall—that slowly moves inward and robs the original, inner eyewall of its needed moisture and angular momentum. Since the strongest winds are in a tropical cyclone's eyewall, the storm usually weakens during this phase, as the inner wall is "choked" by the outer wall. Eventually the outer eyewall replaces the inner one completely, and the storm may re-intensify.
Tropical convective clouds play an important part in the Earth's climate system. Convection and release of latent heat transports energy from the surface into the upper atmosphere. Clouds have a higher albedo than the underlying ocean, which causes more incoming solar radiation to be reflected back to space. Since the tops of tropical systems are much cooler than the surface of the Earth, the presence of high convective clouds cools the climate system.
The Thailand Royal Rainmaking Project was initiated in November 1955 by King Bhumibol Adulyadej. Thai farmers repeatedly suffered the effects of drought. The king resolved to do something about it and proposed a solution to the dearth of rain: artificial rainmaking, or cloud seeding. The program is run by the Department of Royal Rainmaking and Agricultural Aviation. There is no impact evaluation or effectiveness reported.