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89-562: A wildfire , forest fire , or a bushfire is an unplanned, uncontrolled and unpredictable fire in an area of combustible vegetation . Depending on the type of vegetation present, a wildfire may be more specifically identified as a bushfire ( in Australia ), desert fire, grass fire, hill fire, peat fire, prairie fire, vegetation fire, or veld fire. Some natural forest ecosystems depend on wildfire. Wildfires are different from controlled or prescribed burning , which are carried out to provide

178-406: A catalyst , a substance that is not consumed, when added, in any chemical reaction during combustion, but which enables the reactants to combust more readily. Once ignited, a chain reaction must take place whereby fires can sustain their own heat by the further release of heat energy in the process of combustion and may propagate, provided there is a continuous supply of an oxidizer and fuel. If

267-560: A defensible space be maintained by clearing flammable materials within a prescribed distance from the structure. Communities in the Philippines also maintain fire lines 5 to 10 meters (16 to 33 ft) wide between the forest and their village, and patrol these lines during summer months or seasons of dry weather. Continued residential development in fire-prone areas and rebuilding structures destroyed by fires has been met with criticism. The ecological benefits of fire are often overridden by

356-403: A high energy fuel for jet and rocket engines , emits intense green flame, leading to its informal nickname of "Green Dragon". The glow of a flame is complex. Black-body radiation is emitted from soot, gas, and fuel particles, though the soot particles are too small to behave like perfect blackbodies. There is also photon emission by de-excited atoms and molecules in the gases. Much of

445-463: A 15 mile radius. Additionally, Sensaio Tech , based in Brazil and Toronto, has released a sensor device that continuously monitors 14 different variables common in forests, ranging from soil temperature to salinity. This information is connected live back to clients through dashboard visualizations, while mobile notifications are provided regarding dangerous levels. Satellite and aerial monitoring through

534-466: A 24-hour fire day that begins at 10:00 a.m. due to the predictable increase in intensity resulting from the daytime warmth. Climate change promotes the type of weather that makes wildfires more likely. In some areas, an increase of wildfires has been attributed directly to climate change. Evidence from Earth's past also shows more fire in warmer periods. Climate change increases evapotranspiration . This can cause vegetation and soils to dry out. When

623-655: A benefit for people. Modern forest management often engages in prescribed burns to mitigate fire risk and promote natural forest cycles. However, controlled burns can turn into wildfires by mistake. Wildfires can be classified by cause of ignition, physical properties, combustible material present, and the effect of weather on the fire. Wildfire severity results from a combination of factors such as available fuels, physical setting, and weather. Climatic cycles with wet periods that create substantial fuels, followed by drought and heat, often precede severe wildfires. These cycles have been intensified by climate change . Wildfires are

712-461: A combustible material left after a fire is called clinker if its melting point is below the flame temperature, so that it fuses and then solidifies as it cools, and ash if its melting point is above the flame temperature. Fire is a chemical process in which a fuel and an oxidizing agent react, yielding carbon dioxide and water . This process, known as a combustion reaction , does not proceed directly and involves intermediates . Although

801-480: A common type of disaster in some regions, including Siberia (Russia), California (United States), British Columbia (Canada), and Australia . Areas with Mediterranean climates or in the taiga biome are particularly susceptible. Wildfires can severely impact humans and their settlements. Effects include for example the direct health impacts of smoke and fire, as well as destruction of property (especially in wildland–urban interfaces ), and economic losses. There

890-482: A controversial gap in the Late Devonian , charcoal is present ever since. The level of atmospheric oxygen is closely related to the prevalence of charcoal: clearly oxygen is the key factor in the abundance of wildfire. Fire also became more abundant when grasses radiated and became the dominant component of many ecosystems, around 6 to 7 million years ago ; this kindling provided tinder which allowed for

979-608: A fire starts in an area with very dry vegetation, it can spread rapidly. Higher temperatures can also lengthen the fire season. This is the time of year in which severe wildfires are most likely, particularly in regions where snow is disappearing. Weather conditions are raising the risks of wildfires. But the total area burnt by wildfires has decreased. This is mostly because savanna has been converted to cropland , so there are fewer trees to burn. Climate variability including heat waves , droughts , and El Niño , and regional weather patterns, such as high-pressure ridges, can increase

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1068-450: A fire. The most common form of active fire protection is fire sprinklers . To maximize passive fire protection of buildings, building materials and furnishings in most developed countries are tested for fire-resistance , combustibility and flammability . Upholstery , carpeting and plastics used in vehicles and vessels are also tested. Where fire prevention and fire protection have failed to prevent damage, fire insurance can mitigate

1157-716: A long history . Fire was the basis of all early thermal weapons . The Byzantine fleet used Greek fire to attack ships and men. The invention of gunpowder in China led to the fire lance , a flame-thrower weapon dating to around 1000 CE which was a precursor to projectile weapons driven by burning gunpowder . The earliest modern flamethrowers were used by infantry in the First World War , first used by German troops against entrenched French troops near Verdun in February 1915. They were later successfully mounted on armoured vehicles in

1246-529: A new fire detection tool is in operation at the U.S. Department of Agriculture (USDA) Forest Service (USFS) which uses data from the Suomi National Polar-orbiting Partnership (NPP) satellite to detect smaller fires in more detail than previous space-based products. The high-resolution data is used with a computer model to predict how a fire will change direction based on weather and land conditions. In 2014, an international campaign

1335-413: A number expected to rise to 30,000 by 2050. The economic impact is also significant, with projected costs reaching $ 240 billion annually by 2050, surpassing other climate-related damages. Over the past century, wildfires have accounted for 20–25% of global carbon emissions, the remainder from human activities. Global carbon emissions from wildfires through August 2020 equaled the average annual emissions of

1424-543: A policy of allowing some wildfires to burn is the cheapest method and an ecologically appropriate policy for many forests, they tend not to take into account the economic value of resources that are consumed by the fire, especially merchantable timber. Some studies conclude that while fuels may also be removed by logging, such thinning treatments may not be effective at reducing fire severity under extreme weather conditions. Building codes in fire-prone areas typically require that structures be built of flame-resistant materials and

1513-502: A possible resolution to human operator error. These systems may be semi- or fully automated and employ systems based on the risk area and degree of human presence, as suggested by GIS data analyses. An integrated approach of multiple systems can be used to merge satellite data, aerial imagery, and personnel position via Global Positioning System (GPS) into a collective whole for near-realtime use by wireless Incident Command Centers . A small, high risk area that features thick vegetation,

1602-528: A rapid forward rate of spread (FROS) when burning through dense uninterrupted fuels. They can move as fast as 10.8 kilometres per hour (6.7 mph) in forests and 22 kilometres per hour (14 mph) in grasslands. Wildfires can advance tangential to the main front to form a flanking front, or burn in the opposite direction of the main front by backing . They may also spread by jumping or spotting as winds and vertical convection columns carry firebrands (hot wood embers) and other burning materials through

1691-680: A remote site and sent via overnight mail to the fire manager . During the Yellowstone fires of 1988 , a data station was established in West Yellowstone , permitting the delivery of satellite-based fire information in approximately four hours. Public hotlines, fire lookouts in towers, and ground and aerial patrols can be used as a means of early detection of forest fires. However, accurate human observation may be limited by operator fatigue , time of day, time of year, and geographic location. Electronic systems have gained popularity in recent years as

1780-631: A series of mechanisms that behave differently in micro gravity when compared to normal gravity conditions. These discoveries have potential applications in applied science and industry , especially concerning fuel efficiency . The adiabatic flame temperature of a given fuel and oxidizer pair is that at which the gases achieve stable combustion. Fire science is a branch of physical science which includes fire behavior, dynamics, and combustion . Applications of fire science include fire protection , fire investigation , and wildfire management. Every natural ecosystem on land has its own fire regime , and

1869-436: A similar point in time. The use of fire became progressively more sophisticated, as it was used to create charcoal and to control wildlife from tens of thousands of years ago. Fire has also been used for centuries as a method of torture and execution, as evidenced by death by burning as well as torture devices such as the iron boot , which could be filled with water, oil , or even lead and then heated over an open fire to

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1958-564: A strong human presence, or is close to a critical urban area can be monitored using a local sensor network . Detection systems may include wireless sensor networks that act as automated weather systems: detecting temperature, humidity, and smoke. These may be battery-powered, solar-powered, or tree-rechargeable : able to recharge their battery systems using the small electrical currents in plant material. Larger, medium-risk areas can be monitored by scanning towers that incorporate fixed cameras and sensors to detect smoke or additional factors such as

2047-775: A susceptible area: an ignition source is brought into contact with a combustible material such as vegetation that is subjected to enough heat and has an adequate supply of oxygen from the ambient air. A high moisture content usually prevents ignition and slows propagation, because higher temperatures are needed to evaporate any water in the material and heat the material to its fire point . Dense forests usually provide more shade, resulting in lower ambient temperatures and greater humidity , and are therefore less susceptible to wildfires. Less dense material such as grasses and leaves are easier to ignite because they contain less water than denser material such as branches and trunks. Plants continuously lose water by evapotranspiration , but water loss

2136-444: Is also the potential for contamination of water and soil. At a global level, human practices have made the impacts of wildfire worse, with a doubling in land area burned by wildfires compared to natural levels. Humans have impacted wildfire through climate change (e.g. more intense heat waves and droughts ), land-use change , and wildfire suppression . The carbon released from wildfires can add to carbon dioxide concentrations in

2225-537: Is feeding the fire. Fire prevention is intended to reduce sources of ignition. Fire prevention also includes education to teach people how to avoid causing fires. Buildings, especially schools and tall buildings, often conduct fire drills to inform and prepare citizens on how to react to a building fire. Purposely starting destructive fires constitutes arson and is a crime in most jurisdictions. Model building codes require passive fire protection and active fire protection systems to minimize damage resulting from

2314-417: Is its use to clear land for agriculture. Slash-and-burn agriculture is still common across much of tropical Africa, Asia and South America. For small farmers, controlled fires are a convenient way to clear overgrown areas and release nutrients from standing vegetation back into the soil. However, this useful strategy is also problematic. Growing population, fragmentation of forests and warming climate are making

2403-404: Is one of the four classical elements and has been used by humans in rituals , in agriculture for clearing land, for cooking, generating heat and light, for signaling, propulsion purposes, smelting , forging , incineration of waste, cremation , and as a weapon or mode of destruction. The word "fire" originated from Old English Fyr  'Fire, a fire', which can be traced back to

2492-469: Is prone to offset errors, anywhere from 2 to 3 kilometers (1 to 2 mi) for MODIS and AVHRR data and up to 12 kilometers (7.5 mi) for GOES data. Satellites in geostationary orbits may become disabled, and satellites in polar orbits are often limited by their short window of observation time. Cloud cover and image resolution may also limit the effectiveness of satellite imagery. Global Forest Watch provides detailed daily updates on fire alerts. In 2015

2581-405: Is the rapid oxidation of a material (the fuel ) in the exothermic chemical process of combustion , releasing heat , light , and various reaction products . At a certain point in the combustion reaction, called the ignition point, flames are produced. The flame is the visible portion of the fire. Flames consist primarily of carbon dioxide, water vapor, oxygen and nitrogen. If hot enough,

2670-417: Is used by nearly every human being on Earth in a controlled setting every day. Users of internal combustion vehicles employ fire every time they drive. Thermal power stations provide electricity for a large percentage of humanity by igniting fuels such as coal , oil or natural gas , then using the resultant heat to boil water into steam , which then drives turbines . The use of fire in warfare has

2759-412: Is usually balanced by water absorbed from the soil, humidity, or rain. When this balance is not maintained, often as a consequence of droughts , plants dry out and are therefore more flammable. A wildfire front is the portion sustaining continuous flaming combustion, where unburned material meets active flames, or the smoldering transition between unburned and burned material. As the front approaches,

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2848-677: The 2023 Canadian wildfires false claims of arson gained traction on social media; however, arson is generally not a main cause of wildfires in Canada. In California, generally 6–10% of wildfires annually are arson. Coal seam fires burn in the thousands around the world, such as those in Burning Mountain , New South Wales; Centralia , Pennsylvania; and several coal-sustained fires in China . They can also flare up unexpectedly and ignite nearby flammable material. (Fire) Good luck deleting this, Frost! (Fire) The spread of wildfires varies based on

2937-949: The Amazon rainforest . The fires in the latter were caused mainly by illegal logging . The smoke from the fires expanded on huge territory including major cities, dramatically reducing air quality. As of August 2020, the wildfires in that year were 13% worse than in 2019 due primarily to climate change , deforestation and agricultural burning. The Amazon rainforest 's existence is threatened by fires. Record-breaking wildfires in 2021 occurred in Turkey , Greece and Russia , thought to be linked to climate change. The carbon released from wildfires can add to greenhouse gas concentrations. Climate models do not yet fully reflect this feedback . Wildfires release large amounts of carbon dioxide, black and brown carbon particles, and ozone precursors such as volatile organic compounds and nitrogen oxides (NOx) into

3026-553: The European Union . In 2020, the carbon released by California's wildfires was significantly larger than the state's other carbon emissions. Forest fires in Indonesia in 1997 were estimated to have released between 0.81 and 2.57 giga tonnes (0.89 and 2.83 billion short tons ) of CO 2 into the atmosphere, which is between 13–40% of the annual global carbon dioxide emissions from burning fossil fuels. In June and July 2019, fires in

3115-469: The Fire Information for Resource Management System (FIRMS). Between 2022–2023, wildfires throughout North America prompted an uptake in the delivery and design of various technologies using artificial intelligence for early detection, prevention, and prediction of wildfires. Wildfire suppression depends on the technologies available in the area in which the wildfire occurs. In less developed nations

3204-581: The Germanic root * fūr- , which itself comes from the Proto-Indo-European * perjos from the root * paewr- ' fire ' . The current spelling of "fire" has been in use since as early as 1200, but it was not until around 1600 that it completely replaced the Middle English term fier (which is still preserved in the word "fiery"). The fossil record of fire first appears with

3293-495: The Paris climate agreement . Due to the complex oxidative chemistry occurring during the transport of wildfire smoke in the atmosphere, the toxicity of emissions was indicated to increase over time. Atmospheric models suggest that these concentrations of sooty particles could increase absorption of incoming solar radiation during winter months by as much as 15%. The Amazon is estimated to hold around 90 billion tons of carbon. As of 2019,

3382-403: The dry season . In middle latitudes , the most common human causes of wildfires are equipment generating sparks (chainsaws, grinders, mowers, etc.), overhead power lines , and arson . Arson may account for over 20% of human caused fires. However, in the 2019–20 Australian bushfire season "an independent study found online bots and trolls exaggerating the role of arson in the fires." In

3471-408: The flash point for the fuel /oxidizer mix, and is able to sustain a rate of rapid oxidation that produces a chain reaction . This is commonly called the fire tetrahedron . Fire cannot exist without all of these elements in place and in the right proportions. For example, a flammable liquid will start burning only if the fuel and oxygen are in the right proportions. Some fuel-oxygen mixes may require

3560-459: The Arctic emitted more than 140 megatons of carbon dioxide, according to an analysis by CAMS. To put that into perspective this amounts to the same amount of carbon emitted by 36 million cars in a year. The recent wildfires and their massive CO 2 emissions mean that it will be important to take them into consideration when implementing measures for reaching greenhouse gas reduction targets accorded with

3649-567: The Second World War, notably on Coventry , Tokyo , Rotterdam , London , Hamburg and Dresden ; in the latter two cases firestorms were deliberately caused in which a ring of fire surrounding each city was drawn inward by an updraft caused by a central cluster of fires. The United States Army Air Force also extensively used incendiaries against Japanese targets in the latter months of the war, devastating entire cities constructed primarily of wood and paper houses. The incendiary fluid napalm

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3738-496: The Second World War. Hand-thrown incendiary bombs improvised from glass bottles, later known as Molotov cocktails , were deployed during the Spanish Civil War in the 1930s. Also during that war, incendiary bombs were deployed against Guernica by Fascist Italian and Nazi German air forces that had been created specifically to support Franco's Nationalists . Incendiary bombs were dropped by Axis and Allies during

3827-497: The United States in the early 20th century and fires were reported using telephones, carrier pigeons , and heliographs . Aerial and land photography using instant cameras were used in the 1950s until infrared scanning was developed for fire detection in the 1960s. However, information analysis and delivery was often delayed by limitations in communication technology. Early satellite-derived fire analyses were hand-drawn on maps at

3916-467: The agony of the wearer. By the Neolithic Revolution , during the introduction of grain-based agriculture, people all over the world used fire as a tool in landscape management. These fires were typically controlled burns or "cool fires", as opposed to uncontrolled "hot fires", which damage the soil. Hot fires destroy plants and animals, and endanger communities. This is especially a problem in

4005-432: The air over roads, rivers, and other barriers that may otherwise act as firebreaks . Torching and fires in tree canopies encourage spotting, and dry ground fuels around a wildfire are especially vulnerable to ignition from firebrands. Spotting can create spot fires as hot embers and firebrands ignite fuels downwind from the fire. In Australian bushfires , spot fires are known to occur as far as 20 kilometres (12 mi) from

4094-718: The annual number of hot days (above 35 °C) and very hot days (above 40 °C) has increased significantly in many areas of the country since 1950. The country has always had bushfires but in 2019, the extent and ferocity of these fires increased dramatically. For the first time catastrophic bushfire conditions were declared for Greater Sydney. New South Wales and Queensland declared a state of emergency but fires were also burning in South Australia and Western Australia. In 2019, extreme heat and dryness caused massive wildfires in Siberia , Alaska , Canary Islands , Australia , and in

4183-464: The atmosphere and thus contribute to the greenhouse effect . This creates a climate change feedback . Naturally occurring wildfires can have beneficial effects on those ecosystems that have evolved with fire. In fact, many plant species depend on the effects of fire for growth and reproduction. The ignition of a fire takes place through either natural causes or human activity (deliberate or not). Natural occurrences that can ignite wildfires without

4272-441: The atmosphere. These emissions affect radiation, clouds, and climate on regional and even global scales. Wildfires also emit substantial amounts of semi-volatile organic species that can partition from the gas phase to form secondary organic aerosol (SOA) over hours to days after emission. In addition, the formation of the other pollutants as the air is transported can lead to harmful exposures for populations in regions far away from

4361-491: The burning of vegetation releases nitrogen into the atmosphere, unlike elements such as potassium and phosphorus which remain in the ash and are quickly recycled into the soil. This loss of nitrogen caused by a fire produces a long-term reduction in the fertility of the soil, which can be recovered as atmospheric nitrogen is fixed and converted to ammonia by natural phenomena such as lightning or by leguminous plants such as clover , peas , and green beans . Fire

4450-575: The direction of the fire, which can make fires particularly dangerous. For example, during the 1949 Mann Gulch fire in Montana , United States, thirteen smokejumpers died when they lost their communication links, became disoriented, and were overtaken by the fire. In the Australian February 2009 Victorian bushfires , at least 173 people died and over 2,029 homes and 3,500 structures were lost when they became engulfed by wildfire. Fire Fire

4539-688: The earth's atmosphere has 415 parts per million of carbon, and the destruction of the Amazon would add about 38 parts per million. Some research has shown wildfire smoke can have a cooling effect. Research in 2007 stated that black carbon in snow changed temperature three times more than atmospheric carbon dioxide. As much as 94 percent of Arctic warming may be caused by dark carbon on snow that initiates melting. The dark carbon comes from fossil fuels burning, wood and other biofuels, and forest fires. Melting can occur even at low concentrations of dark carbon (below five parts per billion)". Wildfire prevention refers to

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4628-477: The earth's surface more prone to ever-larger escaped fires. These harm ecosystems and human infrastructure, cause health problems, and send up spirals of carbon and soot that may encourage even more warming of the atmosphere – and thus feed back into more fires. Globally today, as much as 5 million square kilometres – an area more than half the size of the United States – burns in a given year. There are numerous modern applications of fire. In its broadest sense, fire

4717-408: The economic and safety benefits of protecting structures and human life. The demand for timely, high-quality fire information has increased in recent years. Fast and effective detection is a key factor in wildfire fighting. Early detection efforts were focused on early response, accurate results in both daytime and nighttime, and the ability to prioritize fire danger. Fire lookout towers were used in

4806-596: The establishment of a land-based flora in the Middle Ordovician period, 470  million years ago , permitting the accumulation of oxygen in the atmosphere as never before, as the new hordes of land plants pumped it out as a waste product. When this concentration rose above 13%, it permitted the possibility of wildfire . Wildfire is first recorded in the Late Silurian fossil record, 420  million years ago , by fossils of charcoalified plants. Apart from

4895-652: The familiar red-orange glow of "fire". This light has a continuous spectrum . Complete combustion of gas has a dim blue color due to the emission of single-wavelength radiation from various electron transitions in the excited molecules formed in the flame. Usually oxygen is involved, but hydrogen burning in chlorine also produces a flame, producing hydrogen chloride (HCl). Other possible combinations producing flames, amongst many, are fluorine and hydrogen , and hydrazine and nitrogen tetroxide . Hydrogen and hydrazine/ UDMH flames are similarly pale blue, while burning boron and its compounds, evaluated in mid-20th century as

4984-400: The fire front. Especially large wildfires may affect air currents in their immediate vicinities by the stack effect : air rises as it is heated, and large wildfires create powerful updrafts that will draw in new, cooler air from surrounding areas in thermal columns . Great vertical differences in temperature and humidity encourage pyrocumulus clouds , strong winds, and fire whirls with

5073-415: The fire heats both the surrounding air and woody material through convection and thermal radiation . First, wood is dried as water is vaporized at a temperature of 100 °C (212 °F). Next, the pyrolysis of wood at 230 °C (450 °F) releases flammable gases. Finally, wood can smolder at 380 °C (720 °F) or, when heated sufficiently, ignite at 590 °C (1,000 °F). Even before

5162-407: The fire. Because of this, the risk of fire in a spacecraft is small when it is coasting in inertial flight. This does not apply if oxygen is supplied to the fire by some process other than thermal convection. Fire can be extinguished by removing any one of the elements of the fire tetrahedron. Consider a natural gas flame, such as from a stove-top burner. The fire can be extinguished by any of

5251-665: The flame becomes spherical, with a tendency to become more blue and more efficient (although it may go out if not moved steadily, as the CO 2 from combustion does not disperse as readily in microgravity, and tends to smother the flame). There are several possible explanations for this difference, of which the most likely is that the temperature is sufficiently evenly distributed that soot is not formed and complete combustion occurs. Experiments by NASA reveal that diffusion flames in microgravity allow more soot to be completely oxidized after they are produced than diffusion flames on Earth, because of

5340-449: The flames of a wildfire arrive at a particular location, heat transfer from the wildfire front warms the air to 800 °C (1,470 °F), which pre-heats and dries flammable materials, causing materials to ignite faster and allowing the fire to spread faster. High-temperature and long-duration surface wildfires may encourage flashover or torching : the drying of tree canopies and their subsequent ignition from below. Wildfires have

5429-420: The flammable material present, its vertical arrangement and moisture content, and weather conditions. Fuel arrangement and density is governed in part by topography , as land shape determines factors such as available sunlight and water for plant growth. Overall, fire types can be generally characterized by their fuels as follows: Wildfires occur when all the necessary elements of a fire triangle come together in

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5518-405: The following: In contrast, fire is intensified by increasing the overall rate of combustion. Methods to do this include balancing the input of fuel and oxidizer to stoichiometric proportions, increasing fuel and oxidizer input in this balanced mix, increasing the ambient temperature so the fire's own heat is better able to sustain combustion, or providing a catalyst, a non-reactant medium in which

5607-595: The food. The heat produced would also help people stay warm in cold weather, enabling them to live in cooler climates. Fire also kept nocturnal predators at bay. Evidence of occasional cooked food is found from 1  million years ago . Although this evidence shows that fire may have been used in a controlled fashion about 1 million years ago, other sources put the date of regular use at 400,000 years ago. Evidence becomes widespread around 50 to 100 thousand years ago, suggesting regular use from this time; resistance to air pollution started to evolve in human populations at

5696-436: The force of tornadoes at speeds of more than 80 kilometres per hour (50 mph). Rapid rates of spread, prolific crowning or spotting, the presence of fire whirls, and strong convection columns signify extreme conditions. Intensity also increases during daytime hours. Burn rates of smoldering logs are up to five times greater during the day due to lower humidity, increased temperatures, and increased wind speeds. Sunlight warms

5785-484: The forests of today where traditional burning is prevented in order to encourage the growth of timber crops. Cool fires are generally conducted in the spring and autumn. They clear undergrowth, burning up biomass that could trigger a hot fire should it get too dense. They provide a greater variety of environments, which encourages game and plant diversity. For humans, they make dense, impassable forests traversable. Another human use for fire in regards to landscape management

5874-460: The fuel and oxidizer can more readily react. A flame is a mixture of reacting gases and solids emitting visible, infrared , and sometimes ultraviolet light, the frequency spectrum of which depends on the chemical composition of the burning material and intermediate reaction products. In many cases, such as the burning of organic matter , for example wood, or the incomplete combustion of gas, incandescent solid particles called soot produce

5963-646: The fuel; how to stoke the fire both in early phases and in maintenance phases; how to modulate the heat, flame, and smoke as suited to the desired application; how best to bank a fire to be revived later; how to choose, design, or modify stoves, fireplaces, bakery ovens, or industrial furnaces ; and so on. Detailed expositions of fire management are available in various books about blacksmithing, about skilled camping or military scouting , and about domestic arts . Burning fuel converts chemical energy into heat energy; wood has been used as fuel since prehistory . The International Energy Agency states that nearly 80% of

6052-756: The gases may become ionized to produce plasma . Depending on the substances alight, and any impurities outside, the color of the flame and the fire's intensity will be different. Fire, in its most common form, has the potential to result in conflagration , which can lead to physical damage, which can be permanent, through burning . Fire is a significant process that influences ecological systems worldwide. The positive effects of fire include stimulating growth and maintaining various ecological systems. Its negative effects include hazard to life and property, atmospheric pollution, and water contamination. When fire removes protective vegetation , heavy rainfall can contribute to increased soil erosion by water . Additionally,

6141-448: The ground during the day which creates air currents that travel uphill. At night the land cools, creating air currents that travel downhill. Wildfires are fanned by these winds and often follow the air currents over hills and through valleys. Fires in Europe occur frequently during the hours of 12:00 p.m. and 2:00 p.m. Wildfire suppression operations in the United States revolve around

6230-487: The infrared signature of carbon dioxide produced by fires. Additional capabilities such as night vision , brightness detection, and color change detection may also be incorporated into sensor arrays . The Department of Natural Resources signed a contract with PanoAI for the installation of 360 degree 'rapid detection' cameras around the Pacific northwest, which are mounted on cell towers and are capable of 24/7 monitoring of

6319-467: The involvement of humans include lightning , volcanic eruptions , sparks from rock falls, and spontaneous combustions . Sources of human-caused fire may include arson, accidental ignition, or the uncontrolled use of fire in land-clearing and agriculture such as the slash-and-burn farming in Southeast Asia. In the tropics , farmers often practice the slash-and-burn method of clearing fields during

6408-637: The majority of wildfires are often extinguished before they grow out of control. While more than 99% of the 10,000 new wildfires each year are contained, escaped wildfires under extreme weather conditions are difficult to suppress without a change in the weather. Wildfires in Canada and the US burn an average of 54,500 square kilometers (13,000,000 acres) per year. Above all, fighting wildfires can become deadly. A wildfire's burning front may also change direction unexpectedly and jump across fire breaks. Intense heat and smoke can lead to disorientation and loss of appreciation of

6497-473: The more rapid spread of fire. These widespread fires may have initiated a positive feedback process, whereby they produced a warmer, drier climate more conducive to fire. The ability to control fire was a dramatic change in the habits of early humans. Making fire to generate heat and light made it possible for people to cook food, simultaneously increasing the variety and availability of nutrients and reducing disease by killing pathogenic microorganisms in

6586-435: The organisms in those ecosystems are adapted to or dependent upon that fire regime. Fire creates a mosaic of different habitat patches, each at a different stage of succession . Different species of plants, animals, and microbes specialize in exploiting a particular stage, and by creating these different types of patches, fire allows a greater number of species to exist within a landscape. Wildfire prevention programs around

6675-407: The oxidizer is oxygen from the surrounding air, the presence of a force of gravity , or of some similar force caused by acceleration, is necessary to produce convection , which removes combustion products and brings a supply of oxygen to the fire. Without gravity, a fire rapidly surrounds itself with its own combustion products and non-oxidizing gases from the air, which exclude oxygen and extinguish

6764-421: The oxidizing agent is typically oxygen , other compounds are able to fulfill the role. For instance, chlorine trifluoride is able to ignite sand . Fires start when a flammable or a combustible material, in combination with a sufficient quantity of an oxidizer such as oxygen gas or another oxygen-rich compound (though non-oxygen oxidizers exist), is exposed to a source of heat or ambient temperature above

6853-476: The preemptive methods aimed at reducing the risk of fires as well as lessening its severity and spread. Prevention techniques aim to manage air quality, maintain ecological balances, protect resources, and to affect future fires. Prevention policies must consider the role that humans play in wildfires, since, for example, 95% of forest fires in Europe are related to human involvement. Wildfire prevention programs around

6942-495: The radiation is emitted in the visible and infrared bands. The color depends on temperature for the black-body radiation, and on chemical makeup for the emission spectra . The common distribution of a flame under normal gravity conditions depends on convection , as soot tends to rise to the top of a general flame, as in a candle in normal gravity conditions, making it yellow. In microgravity or zero gravity , such as an environment in outer space , convection no longer occurs, and

7031-574: The risk and alter the behavior of wildfires dramatically. Years of high precipitation can produce rapid vegetation growth, which when followed by warmer periods can encourage more widespread fires and longer fire seasons. High temperatures dry out the fuel loads and make them more flammable, increasing tree mortality and posing significant risks to global forest health. Since the mid-1980s, in the Western US, earlier snowmelt and associated warming has also been associated with an increase in length and severity of

7120-428: The techniques used can be as simple as throwing sand or beating the fire with sticks or palm fronds. In more advanced nations, the suppression methods vary due to increased technological capacity. Silver iodide can be used to encourage snow fall, while fire retardants and water can be dropped onto fires by unmanned aerial vehicles , planes , and helicopters . Complete fire suppression is no longer an expectation, but

7209-930: The use of planes, helicopter, or UAVs can provide a wider view and may be sufficient to monitor very large, low risk areas. These more sophisticated systems employ GPS and aircraft-mounted infrared or high-resolution visible cameras to identify and target wildfires. Satellite-mounted sensors such as Envisat 's Advanced Along Track Scanning Radiometer and European Remote-Sensing Satellite 's Along-Track Scanning Radiometer can measure infrared radiation emitted by fires, identifying hot spots greater than 39 °C (102 °F). The National Oceanic and Atmospheric Administration 's Hazard Mapping System combines remote-sensing data from satellite sources such as Geostationary Operational Environmental Satellite (GOES), Moderate-Resolution Imaging Spectroradiometer (MODIS), and Advanced Very High Resolution Radiometer (AVHRR) for detection of fire and smoke plume locations. However, satellite detection

7298-585: The wildfire season, or the most fire-prone time of the year. A 2019 study indicates that the increase in fire risk in California may be partially attributable to human-induced climate change . In the summer of 1974–1975 (southern hemisphere), Australia suffered its worst recorded wildfire, when 15% of Australia's land mass suffered "extensive fire damage". Fires that summer burned up an estimated 117 million hectares (290 million acres ; 1,170,000 square kilometres ; 450,000 square miles ). In Australia,

7387-408: The wildfires. While direct emissions of harmful pollutants can affect first responders and residents, wildfire smoke can also be transported over long distances and impact air quality across local, regional, and global scales. The health effects of wildfire smoke, such as worsening cardiovascular and respiratory conditions, extend beyond immediate exposure, contributing to nearly 16,000 annual deaths,

7476-515: The world may employ techniques such as wildland fire use (WFU) and prescribed or controlled burns . Wildland fire use refers to any fire of natural causes that is monitored but allowed to burn. Controlled burns are fires ignited by government agencies under less dangerous weather conditions. Other objectives can include maintenance of healthy forests, rangelands, and wetlands, and support of ecosystem diversity. Strategies for wildfire prevention, detection, control and suppression have varied over

7565-573: The world may employ techniques such as wildland fire use and prescribed or controlled burns . Wildland fire use refers to any fire of natural causes that is monitored but allowed to burn. Controlled burns are fires ignited by government agencies under less dangerous weather conditions. Fire fighting services are provided in most developed areas to extinguish or contain uncontrolled fires. Trained firefighters use fire apparatus , water supply resources such as water mains and fire hydrants or they might use A and B class foam depending on what

7654-462: The world's power has consistently come from fossil fuels such as petroleum , natural gas , and coal in the past decades. The fire in a power station is used to heat water, creating steam that drives turbines . The turbines then spin an electric generator to produce electricity. Fire is also used to provide mechanical work directly by thermal expansion , in both external and internal combustion engines . The unburnable solid remains of

7743-461: The years. One common and inexpensive technique to reduce the risk of uncontrolled wildfires is controlled burning : intentionally igniting smaller less-intense fires to minimize the amount of flammable material available for a potential wildfire. Vegetation may be burned periodically to limit the accumulation of plants and other debris that may serve as fuel, while also maintaining high species diversity. While other people claim that controlled burns and

7832-761: Was organized in South Africa's Kruger National Park to validate fire detection products including the new VIIRS active fire data. In advance of that campaign, the Meraka Institute of the Council for Scientific and Industrial Research in Pretoria, South Africa, an early adopter of the VIIRS 375 m fire product, put it to use during several large wildfires in Kruger. Since 2021 NASA has provided active fire locations in near real-time via

7921-637: Was used in July 1944, towards the end of the Second World War , although its use did not gain public attention until the Vietnam War . Controlling a fire to optimize its size, shape, and intensity is generally called fire management , and the more advanced forms of it, as traditionally (and sometimes still) practiced by skilled cooks, blacksmiths , ironmasters , and others, are highly skilled activities. They include knowledge of which fuel to burn; how to arrange

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