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Tornado

A tornado is a violently rotating column of air that is in contact with both the surface of the Earth and a cumulonimbus cloud or, in rare cases, the base of a cumulus cloud. It is often referred to as a twister, whirlwind or cyclone, although the word cyclone is used in meteorology to name a weather system with a low-pressure area in the center around which, from an observer looking down toward the surface of the Earth, winds blow counterclockwise in the Northern Hemisphere and clockwise in the Southern. Tornadoes come in many shapes and sizes, and they are often (but not always) visible in the form of a condensation funnel originating from the base of a cumulonimbus cloud, with a cloud of rotating debris and dust beneath it. Most tornadoes have wind speeds less than 110 mph, are about 250 ft across, and travel several kilometers (a few miles) before dissipating. The most extreme tornadoes can attain wind speeds of more than 300 mph, are more than 2 mi in diameter, and stay on the ground for more than 100 km.

Various types of tornadoes include the multiple-vortex tornado, landspout, and waterspout. Waterspouts are characterized by a spiraling funnel-shaped wind current, connecting to a large cumulus or cumulonimbus cloud. They are generally classified as non-supercellular tornadoes that develop over bodies of water, but there is disagreement over whether to classify them as true tornadoes. These spiraling columns of air frequently develop in tropical areas close to the equator and are less common at high latitudes. Other tornado-like phenomena that exist in nature include the gustnado, dust devil, fire whirl, and steam devil.

Tornadoes occur most frequently in North America (particularly in central and southeastern regions of the United States colloquially known as Tornado Alley; the United States and Canada have by far the most tornadoes of any countries in the world). Tornadoes also occur in South Africa, much of Europe (except most of the Alps), western and eastern Australia, New Zealand, Bangladesh and adjacent eastern India, Japan, the Philippines, and southeastern South America (Uruguay and Argentina). Tornadoes can be detected before or as they occur through the use of pulse-Doppler radar by recognizing patterns in velocity and reflectivity data, such as hook echoes or debris balls, as well as through the efforts of storm spotters.

Tornado rating scales
There are several scales for rating the strength of tornadoes. The Fujita scale rates tornadoes by damage caused and has been replaced in some countries by the updated Enhanced Fujita Scale. An F0 or EF0 tornado, the weakest category, damages trees, but not substantial structures. An F5 or EF5 tornado, the strongest category, rips buildings off their foundations and can deform large skyscrapers. The similar TORRO scale ranges from T0 for extremely weak tornadoes to T11 for the most powerful known tornadoes. The International Fujita scale is also used to rate the intensity of tornadoes and other wind events based on the severity of the damage they cause. Doppler radar data, photogrammetry, and ground swirl patterns (trochoidal marks) may also be analyzed to determine intensity and assign a rating.

Etymology
The word tornado comes from the Spanish tronada (meaning 'thunderstorm', past participle of tronar 'to thunder', itself in turn from the Latin tonāre 'to thunder'). The metathesis of the r and o in the English spelling was influenced by the Spanish tornado (past participle of tornar 'to twist, turn,', from Latin tornō 'to turn'). The English word has been reborrowed into Spanish, referring to the same weather phenomenon.

Tornadoes' opposite phenomena are the widespread, straight-line derechos (, from derecho, 'straight'). A tornado is also commonly referred to as a "twister" or the old-fashioned colloquial term cyclone.

Definitions
A tornado is a violently rotating column of air, in contact with the ground, either pendant from a cumuliform cloud or underneath a cumuliform cloud, and often (but not always) visible as a funnel cloud. For a vortex to be classified as a tornado, it must be in contact with both the ground and the cloud base. The term is not precisely defined; for example, there is disagreement as to whether separate touchdowns of the same funnel constitute separate tornadoes. Tornado refers to the vortex of wind, not the condensation cloud.

Funnel cloud
A tornado is not necessarily visible; however, the intense low pressure caused by the high wind speeds (as described by Bernoulli's principle) and rapid rotation (due to cyclostrophic balance) usually cause water vapor in the air to condense into cloud droplets due to adiabatic cooling. This results in the formation of a visible funnel cloud or condensation funnel.

There is some disagreement over the definition of a funnel cloud and a condensation funnel. According to the Glossary of Meteorology, a funnel cloud is any rotating cloud pendant from a cumulus or cumulonimbus, and thus most tornadoes are included under this definition. Among many meteorologists, the "funnel cloud" term is strictly defined as a rotating cloud which is not associated with strong winds at the surface, and condensation funnel is a broad term for any rotating cloud below a cumuliform cloud.

Tornadoes often begin as funnel clouds with no associated strong winds at the surface, and not all funnel clouds evolve into tornadoes. Most tornadoes produce strong winds at the surface while the visible funnel is still above the ground, so it is difficult to discern the difference between a funnel cloud and a tornado from a distance.

Outbreaks and families
Occasionally, a single storm will produce more than one tornado, either simultaneously or in succession. Multiple tornadoes produced by the same storm cell are referred to as a "tornado family". Several tornadoes are sometimes spawned from the same large-scale storm system. If there is no break in activity, this is considered a tornado outbreak (although the term "tornado outbreak" has various definitions). A period of several successive days with tornado outbreaks in the same general area (spawned by multiple weather systems) is a tornado outbreak sequence, occasionally called an extended tornado outbreak.

Size and shape
Most tornadoes take on the appearance of a narrow funnel, a few hundred meters (yards) across, with a small cloud of debris near the ground. Tornadoes may be obscured completely by rain or dust. These tornadoes are especially dangerous, as even experienced meteorologists might not see them.

Small, relatively weak landspouts may be visible only as a small swirl of dust on the ground. Although the condensation funnel may not extend all the way to the ground, if associated surface winds are greater than 40 mph, the circulation is considered a tornado. A tornado with a nearly cylindrical profile and relatively low height is sometimes referred to as a "stovepipe" tornado. Large tornadoes which appear at least as wide as their cloud-to-ground height can look like large wedges stuck into the ground, and so are known as "wedge tornadoes" or "wedges". The "stovepipe" classification is also used for this type of tornado if it otherwise fits that profile. A wedge can be so wide that it appears to be a block of dark clouds, wider than the distance from the cloud base to the ground. Even experienced storm observers may not be able to tell the difference between a low-hanging cloud and a wedge tornado from a distance. Many, but not all major tornadoes are wedges.

Tornadoes in the dissipating stage can resemble narrow tubes or ropes, and often curl or twist into complex shapes. These tornadoes are said to be "roping out", or becoming a "rope tornado". When they rope out, the length of their funnel increases, which forces the winds within the funnel to weaken due to conservation of angular momentum. Multiple-vortex tornadoes can appear as a family of swirls circling a common center, or they may be completely obscured by condensation, dust, and debris, appearing to be a single funnel.

In the United States, tornadoes are around 500 ft across on average. However, there is a wide range of tornado sizes. Weak tornadoes, or strong yet dissipating tornadoes, can be exceedingly narrow, sometimes only a few feet or couple meters across. One tornado was reported to have a damage path only 7 ft long. On the other end of the spectrum, wedge tornadoes can have a damage path a mile (1.6 km) wide or more. A tornado that affected Hallam, Nebraska on May 22, 2004, was up to 2.5 mi wide at the ground, and a tornado in El Reno, Oklahoma on May 31, 2013, was approximately 2.6 mi wide, the widest on record.

Track length
In the United States, the average tornado travels on the ground for 5 mi. However, tornadoes are capable of both much shorter and much longer damage paths: one tornado was reported to have a damage path only 7 ft long, while the record-holding tornado for path length—the Tri-State Tornado, which affected parts of Missouri, Illinois, and Indiana on March 18, 1925—was on the ground continuously for 219 mi. Many tornadoes which appear to have path lengths of 100 mi or longer are composed of a family of tornadoes which have formed in quick succession; however, there is no substantial evidence that this occurred in the case of the Tri-State Tornado. In fact, modern reanalysis of the path suggests that the tornado may have begun 15 mi further west than previously thought.

Appearance
Tornadoes can have a wide range of colors, depending on the environment in which they form. Those that form in dry environments can be nearly invisible, marked only by swirling debris at the base of the funnel. Condensation funnels that pick up little or no debris can be gray to white. While traveling over a body of water (as a waterspout), tornadoes can turn white or even blue. Slow-moving funnels, which ingest a considerable amount of debris and dirt, are usually darker, taking on the color of debris. Tornadoes in the Great Plains can turn red because of the reddish tint of the soil, and tornadoes in mountainous areas can travel over snow-covered ground, turning white.

Lighting conditions are a major factor in the appearance of a tornado. A tornado which is "back-lit" (viewed with the sun behind it) appears very dark. The same tornado, viewed with the sun at the observer's back, may appear gray or brilliant white. Tornadoes which occur near the time of sunset can be many different colors, appearing in hues of yellow, orange, and pink.

Dust kicked up by the winds of the parent thunderstorm, heavy rain and hail, and the darkness of night are all factors that can reduce the visibility of tornadoes. Tornadoes occurring in these conditions are especially dangerous, since only weather radar observations, or possibly the sound of an approaching tornado, serve as any warning to those in the storm's path. Most significant tornadoes form under the storm's updraft base, which is rain-free, making them visible. Also, most tornadoes occur in the late afternoon, when the bright sun can penetrate even the thickest clouds.

There is mounting evidence, including Doppler on Wheels mobile radar images and eyewitness accounts, that most tornadoes have a clear, calm center with extremely low pressure, akin to the eye of tropical cyclones. Lightning is said to be the source of illumination for those who claim to have seen the interior of a tornado.

Rotation
Tornadoes normally rotate cyclonically (when viewed from above, this is counterclockwise in the northern hemisphere and clockwise in the southern). While large-scale storms always rotate cyclonically due to the Coriolis effect, thunderstorms and tornadoes are so small that the direct influence of the Coriolis effect is negligible, as indicated by their large Rossby numbers. Supercells and tornadoes rotate cyclonically in numerical simulations even when the Coriolis effect is neglected. Low-level mesocyclones and tornadoes owe their rotation to complex processes within the supercell and ambient environment.

Approximately 1 percent of tornadoes rotate in an anticyclonic direction in the northern hemisphere. Typically, systems as weak as landspouts and gustnadoes can rotate anticyclonically, and usually only those which form on the anticyclonic shear side of the descending rear flank downdraft (RFD) in a cyclonic supercell. On rare occasions, anticyclonic tornadoes form in association with the mesoanticyclone of an anticyclonic supercell, in the same manner as the typical cyclonic tornado, or as a companion tornado either as a satellite tornado or associated with anticyclonic eddies within a supercell.

Sound and seismology
Tornadoes emit widely on the acoustics spectrum and the sounds are caused by multiple mechanisms. Various sounds of tornadoes have been reported, mostly related to familiar sounds for the witness and generally some variation of a whooshing roar. Popularly reported sounds include a freight train, rushing rapids or waterfall, a nearby jet engine, or combinations of these. Many tornadoes are not audible from much distance; the nature of and the propagation distance of the audible sound depends on atmospheric conditions and topography.

The winds of the tornado vortex and of constituent turbulent eddies, as well as airflow interaction with the surface and debris, contribute to the sounds. Funnel clouds also produce sounds. Funnel clouds and small tornadoes are reported as whistling, whining, humming, or the buzzing of innumerable bees or electricity, or more or less harmonic, whereas many tornadoes are reported as a continuous, deep rumbling, or an irregular sound of "noise".

Since many tornadoes are audible only when very near, sound is not to be thought of as a reliable warning signal for a tornado. Tornadoes are also not the only source of such sounds in severe thunderstorms; any strong, damaging wind, a severe hail volley, or continuous thunder in a thunderstorm may produce a roaring sound.

Tornadoes also produce identifiable inaudible infrasonic signatures.

Unlike audible signatures, tornadic signatures have been isolated; due to the long-distance propagation of low-frequency sound, efforts are ongoing to develop tornado prediction and detection devices with additional value in understanding tornado morphology, dynamics, and creation. Tornadoes also produce a detectable seismic signature, and research continues on isolating it and understanding the process.

Electromagnetic, lightning, and other effects
Tornadoes emit on the electromagnetic spectrum, with sferics and E-field effects detected. There are observed correlations between tornadoes and patterns of lightning. Tornadic storms do not contain more lightning than other storms and some tornadic cells never produce lightning at all. More often than not, overall cloud-to-ground (CG) lightning activity decreases as a tornado touches the surface and returns to the baseline level when the tornado dissipates. In many cases, intense tornadoes and thunderstorms exhibit an increased and anomalous dominance of positive polarity CG discharges.

Luminosity has been reported in the past and is probably due to misidentification of external light sources such as lightning, city lights, and power flashes from broken lines, as internal sources are now uncommonly reported and are not known to ever have been recorded. In addition to winds, tornadoes also exhibit changes in atmospheric variables such as temperature, moisture, and atmospheric pressure. For example, on June 24, 2003, near Manchester, South Dakota, a probe measured a 100 mbar pressure decrease. The pressure dropped gradually as the vortex approached then dropped extremely rapidly to 850 mbar in the core of the violent tornado before rising rapidly as the vortex moved away, resulting in a V-shape pressure trace. Temperature tends to decrease and moisture content to increase in the immediate vicinity of a tornado.

Life cycle

Supercell relationship
Tornadoes often develop from a class of thunderstorms known as supercells. Supercells contain mesocyclones, an area of organized rotation a few kilometers/miles up in the atmosphere, usually 1 – across. Most intense tornadoes (EF3 to EF5 on the Enhanced Fujita Scale) develop from supercells. In addition to tornadoes, very heavy rain, frequent lightning, strong wind gusts, and hail are common in such storms.

Most tornadoes from supercells follow a recognizable life cycle which begins when increasing rainfall drags with it an area of quickly descending air known as the rear flank downdraft (RFD). This downdraft accelerates as it approaches the ground, and drags the supercell's rotating mesocyclone towards the ground with it.

Formation

As the mesocyclone lowers below the cloud base, it begins to take in cool, moist air from the downdraft region of the storm. The convergence of warm air in the updraft and cool air causes a rotating wall cloud to form. The RFD also focuses the mesocyclone's base, causing it to draw air from a smaller and smaller area on the ground. As the updraft intensifies, it creates an area of low pressure at the surface. This pulls the focused mesocyclone down, in the form of a visible condensation funnel. As the funnel descends, the RFD also reaches the ground, fanning outward and creating a gust front that can cause severe damage a considerable distance from the tornado. Usually, the funnel cloud begins causing damage on the ground (becoming a tornado) within a few minutes of the RFD reaching the ground. Many other aspects of tornado formation (such as why some storms form tornadoes while others do not, or what precise role downdrafts, temperature, and moisture play in tornado formation) are still poorly understood.

Maturity
Initially, the tornado has a good source of warm, moist air flowing inward to power it, and it grows until it reaches the "mature stage". This can last from a few minutes to more than an hour, and during that time a tornado often causes the most damage, and in rare cases can be more than 1 mi across. The low pressured atmosphere at the base of the tornado is essential to the endurance of the system. Meanwhile, the RFD, now an area of cool surface winds, begins to wrap around the tornado, cutting off the inflow of warm air which previously fed the tornado. The flow inside the funnel of the tornado is downward, supplying water vapor from the cloud above. This is contrary to the upward flow inside hurricanes, supplying water vapor from the warm ocean below. Therefore, the energy of the tornado is supplied from the cloud above. The complicated mechanism is explained in

Dissipation
As the RFD completely wraps around and chokes off the tornado's air supply, the vortex begins to weaken, becoming thin and rope-like. This is the "dissipating stage", often lasting no more than a few minutes, after which the tornado ends. During this stage, the shape of the tornado becomes highly influenced by the winds of the parent storm, and can be blown into fantastic patterns. Even though the tornado is dissipating, it is still capable of causing damage. The storm is contracting into a rope-like tube and, due to conservation of angular momentum, winds can increase at this point.

As the tornado enters the dissipating stage, its associated mesocyclone often weakens as well, as the rear flank downdraft cuts off the inflow powering it. Sometimes, in intense supercells, tornadoes can develop cyclically. As the first mesocyclone and associated tornado dissipate, the storm's inflow may be concentrated into a new area closer to the center of the storm and possibly feed a new mesocyclone. If a new mesocyclone develops, the cycle may start again, producing one or more new tornadoes. Occasionally, the old (occluded) mesocyclone and the new mesocyclone produce a tornado at the same time.

Although this is a widely accepted theory for how most tornadoes form, live, and die, it does not explain the formation of smaller tornadoes, such as landspouts, long-lived tornadoes, or tornadoes with multiple vortices. These each have different mechanisms which influence their development—however, most tornadoes follow a pattern similar to this one.

Multiple vortex
A multiple-vortex tornado is a type of tornado in which two or more columns of spinning air rotate about their own axes and

at the same time revolve around a common center. A multi-vortex structure can occur in almost any circulation, but is very often observed in intense tornadoes. These vortices often create small areas of heavier damage along the main tornado path. This is a phenomenon that is distinct from a satellite tornado, which is a smaller tornado that forms very near a large, strong tornado contained within the same mesocyclone. The satellite tornado may appear to "orbit" the larger tornado (hence the name), giving the appearance of one, large multi-vortex tornado. However, a satellite tornado is a distinct circulation, and is much smaller than the main funnel.

Waterspout

A waterspout is defined by the National Weather Service as a tornado over water. However, researchers typically distinguish "fair weather" waterspouts from tornadic (i.e. associated with a mesocyclone) waterspouts. Fair weather waterspouts are less severe but far more common, and are similar to dust devils and landspouts. They form at the bases of cumulus congestus clouds over tropical and subtropical waters. They have relatively weak winds, smooth laminar walls, and typically travel very slowly. They occur most commonly in the Florida Keys and in the northern Adriatic Sea. In contrast, tornadic waterspouts are stronger tornadoes over water. They form over water similarly to mesocyclonic tornadoes, or are stronger tornadoes which cross over water. Since they form from severe thunderstorms and can be far more intense, faster, and longer-lived than fair weather waterspouts, they are more dangerous. In official tornado statistics, waterspouts are generally not counted unless they affect land, though some European weather agencies count waterspouts and tornadoes together.

Landspout
A landspout, or dust-tube tornado, is a tornado not associated with a mesocyclone. The name stems from their characterization as a "fair weather waterspout on land". Waterspouts and landspouts share many defining characteristics, including relative weakness, short lifespan, and a small, smooth condensation funnel that often does not reach the surface. Landspouts also create a distinctively laminar cloud of dust when they make contact with the ground, due to their differing mechanics from true mesoform tornadoes. Though usually weaker than classic tornadoes, they can produce strong winds which could cause serious damage.

Gustnado
A gustnado, or gust front tornado, is a small, vertical swirl associated with a gust front or downburst. Because they are not connected with a cloud base, there is some debate as to whether or not gustnadoes are tornadoes. They are formed when fast-moving cold, dry outflow air from a thunderstorm is blown through a mass of stationary, warm, moist air near the outflow boundary, resulting in a "rolling" effect (often exemplified through a roll cloud). If low level wind shear is strong enough, the rotation can be turned vertically or diagonally and make contact with the ground. The result is a gustnado. They usually cause small areas of heavier rotational wind damage among areas of straight-line wind damage.

Dust devil

A dust devil (also known as a whirlwind) resembles a tornado in that it is a vertical swirling column of air. However, they form under clear skies and are no stronger than the weakest tornadoes. They form when a strong convective updraft is formed near the ground on a hot day. If there is enough low-level wind shear, the column of hot, rising air can develop a small cyclonic motion that can be seen near the ground. They are not considered tornadoes because they form during fair weather and are not associated with any clouds. However, they can, on occasion, result in major damage.

Fire whirls
Small-scale, tornado-like circulations can occur near any intense surface heat source. Those that occur near intense wildfires are called fire whirls. They are not considered tornadoes, except in the rare case where they connect to a pyrocumulus or other cumuliform cloud above. Fire whirls usually are not as strong as tornadoes associated with thunderstorms. They can, however, produce significant damage.

Steam devils
A steam devil is a rotating updraft between 50 and 200 m that involves steam or smoke. These formations do not involve high wind speeds, only completing a few rotations per minute. Steam devils are very rare. They most often form from smoke issuing from a power plant's smokestack. Hot springs and deserts may also be suitable locations for a tighter, faster-rotating steam devil to form. The phenomenon can occur over water, when cold arctic air passes over relatively warm water.

Intensity and damage
The Fujita scale and the Enhanced Fujita Scale rate tornadoes by damage caused. The Enhanced Fujita (EF) Scale was an update to the older Fujita scale, by expert elicitation, using engineered wind estimates and better damage descriptions. The EF Scale was designed so that a tornado rated on the Fujita scale would receive the same numerical rating, and was implemented starting in the United States in 2007. An EF0 tornado will probably damage trees but not substantial structures, whereas an EF5 tornado can rip buildings off their foundations leaving them bare and even deform large skyscrapers. The similar TORRO scale ranges from a T0 for extremely weak tornadoes to T11 for the most powerful known tornadoes. Doppler weather radar data, photogrammetry, and ground swirl patterns (cycloidal marks) may also be analyzed to determine intensity and award a rating.

Tornadoes vary in intensity regardless of shape, size, and location, though strong tornadoes are typically larger than weak tornadoes. The association with track length and duration also varies, although longer track tornadoes tend to be stronger. In the case of violent tornadoes, only a small portion of the path is of violent intensity, most of the higher intensity from subvortices.

In the United States, 80% of tornadoes are EF0 and EF1 (T0 through T3) tornadoes. The rate of occurrence drops off quickly with increasing strength—less than 1% are violent tornadoes (EF4, T8 or stronger). Current records may significantly underestimate the frequency of strong (EF2-EF3) and violent (EF4-EF5) tornadoes, as damage-based intensity estimates are limited to structures and vegetation that a tornado impacts. A tornado may be much stronger than its damage-based rating indicates if its strongest winds occur away from suitable damage indicators, such as in an open field. Outside Tornado Alley, and North America in general, violent tornadoes are extremely rare. This is apparently mostly due to the lesser number of tornadoes overall, as research shows that tornado intensity distributions are fairly similar worldwide. A few significant tornadoes occur annually in Europe, Asia, southern Africa, and southeastern South America.

Climatology

The United States has the most tornadoes of any country, nearly four times more than estimated in all of Europe, excluding waterspouts. This is mostly due to the unique geography of the continent. North America is a large continent that extends from the tropics north into arctic areas, and has no major east–west mountain range to block air flow between these two areas. In the middle latitudes, where most tornadoes of the world occur, the Rocky Mountains block moisture and buckle the atmospheric flow, forcing drier air at mid-levels of the troposphere due to downsloped winds, and causing the formation of a low pressure area downwind to the east of the mountains. Increased westerly flow off the Rockies force the formation of a dry line when the flow aloft is strong, while the Gulf of Mexico fuels abundant low-level moisture in the southerly flow to its east. This unique topography allows for frequent collisions of warm and cold air, the conditions that breed strong, long-lived storms throughout the year. A large portion of these tornadoes form in an area of the central United States known as Tornado Alley. This area extends into Canada, particularly Ontario and the Prairie Provinces, although southeast Quebec, the interior of British Columbia, and western New Brunswick are also tornado-prone. Tornadoes also occur across northeastern Mexico.

The United States averages about 1,200 tornadoes per year, followed by Canada, averaging 62 reported per year. NOAA's has a higher average 100 per year in Canada. The Netherlands has the highest average number of recorded tornadoes per area of any country (more than 20, or 0.00048 /km2 annually), followed by the UK (around 33, 0.00013 /km2 per year), although those are of lower intensity, briefer and cause minor damage.

Tornadoes kill an average of 179 people per year in Bangladesh, the most in the world. Reasons for this include the region's high population density, poor construction quality, and lack of tornado safety knowledge. Other areas of the world that have frequent tornadoes include South Africa, the La Plata Basin area, portions of Europe, Australia and New Zealand, and far eastern Asia.

Tornadoes are most common in spring and least common in winter, but tornadoes can occur any time of year that favorable conditions occur. Spring and fall experience peaks of activity as those are the seasons when stronger winds, wind shear, and atmospheric instability are present. Tornadoes are focused in the right front quadrant of landfalling tropical cyclones, which tend to occur in the late summer and autumn. Tornadoes can also be spawned as a result of eyewall mesovortices, which persist until landfall.

Tornado occurrence is highly dependent on the time of day, because of solar heating. Worldwide, most tornadoes occur in the late afternoon, between 15:00 (3 pm) and 19:00 (7 pm) local time, with a peak near 17:00 (5 pm). Destructive tornadoes can occur at any time of day. The Gainesville Tornado of 1936, one of the deadliest tornadoes in history, occurred at 8:30 am local time.

The United Kingdom has the highest incidence of tornadoes per unit area of land in the world. Unsettled conditions and weather fronts transverse the British Isles at all times of the years, and are responsible for spawning the tornadoes, which consequently form at all times of the year. The United Kingdom has at least 34 tornadoes per year and possibly as many as 50. Most tornadoes in the United Kingdom are weak, but they are occasionally destructive. For example, the Birmingham tornado of 2005 and the London tornado of 2006 both registered F2 on the Fujita scale and both caused significant damage and injury.

Associations with climate and climate change
Associations with various climate and environmental trends exist. For example, an increase in the sea surface temperature of a source region (e.g. Gulf of Mexico and Mediterranean Sea) increases atmospheric moisture content. Increased moisture can fuel an increase in severe weather and tornado activity, particularly in the cool season.

Some evidence does suggest that the Southern Oscillation is weakly correlated with changes in tornado activity, which vary by season and region, as well as whether the ENSO phase is that of El Niño or La Niña. Research has found that fewer tornadoes and hailstorms occur in winter and spring in the U.S. central and southern plains during El Niño, and more occur during La Niña, than in years when temperatures in the Pacific are relatively stable. Ocean conditions could be used to forecast extreme spring storm events several months in advance.

Climatic shifts may affect tornadoes via teleconnections in shifting the jet stream and the larger weather patterns. The climate-tornado link is confounded by the forces affecting larger patterns and by the local, nuanced nature of tornadoes. Although it is reasonable to suspect that global warming may affect trends in tornado activity, any such effect is not yet identifiable due to the complexity, local nature of the storms, and database quality issues. Any effect would vary by region.

Detection

Rigorous attempts to warn of tornadoes began in the United States in the mid-20th century. Before the 1950s, the only method of detecting a tornado was by someone seeing it on the ground. Often, news of a tornado would reach a local weather office after the storm. However, with the advent of weather radar, areas near a local office could get advance warning of severe weather. The first public tornado warnings were issued in 1950 and the first tornado watches and convective outlooks came about in 1952. In 1953, it was confirmed that hook echoes were associated with tornadoes. By recognizing these radar signatures, meteorologists could detect thunderstorms probably producing tornadoes from several miles away.

Radar
Today most developed countries have a network of weather radars, which serves as the primary method of detecting hook signatures that are likely associated with tornadoes. In the United States and a few other countries, Doppler weather radar stations are used. These devices measure the velocity and radial direction (towards or away from the radar) of the winds within a storm, and so can spot evidence of rotation in storms from over 100 mi away. When storms are distant from a radar, only areas high within the storm are observed and the important areas below are not sampled. Data resolution also decreases with distance from the radar. Some meteorological situations leading to tornadogenesis are not readily detectable by radar and tornado development may occasionally take place more quickly than radar can complete a scan and send the batch of data. Doppler weather radar systems can detect mesocyclones within a supercell thunderstorm. This allows meteorologists to predict tornado formations throughout thunderstorms.

Storm spotting
Spotters usually are trained by the NWS on behalf of their respective organizations, and report to them. The organizations activate public warning systems such as sirens and the Emergency Alert System (EAS), and they forward the report to the NWS. There are more than 230,000 trained Skywarn weather spotters across the United States.

In Canada, a similar network of volunteer weather watchers, called Canwarn, helps spot severe weather, with more than 1,000 volunteers. In Europe, several nations are organizing spotter networks under the auspices of Skywarn Europe and the Tornado and Storm Research Organisation (TORRO) has maintained a network of spotters in the United Kingdom since 1974.

Storm spotters are required because radar systems such as NEXRAD detect signatures that suggest the presence of tornadoes, rather than tornadoes as such. Radar may give a warning before there is any visual evidence of a tornado or an imminent one, but ground truth from an observer can give definitive information. The spotter's ability to see what radar cannot is especially important as distance from the radar site increases, because the radar beam becomes progressively higher in altitude further away from the radar, chiefly due to curvature of Earth, and the beam also spreads out.

Visual evidence
Storm spotters are trained to discern whether or not a storm seen from a distance is a supercell. They typically look to its rear, the main region of updraft and inflow. Under that updraft is a rain-free base, and the next step of tornadogenesis is the formation of a rotating wall cloud. The vast majority of intense tornadoes occur with a wall cloud on the backside of a supercell.

Evidence of a supercell is based on the storm's shape and structure, and cloud tower features such as a hard and vigorous updraft tower, a persistent, large overshooting top, a hard anvil (especially when backsheared against strong upper level winds), and a corkscrew look or striations. Under the storm and closer to where most tornadoes are found, evidence of a supercell and the likelihood of a tornado includes inflow bands (particularly when curved) such as a "beaver tail", and other clues such as strength of inflow, warmth and moistness of inflow air, how outflow- or inflow-dominant a storm appears, and how far is the front flank precipitation core from the wall cloud. Tornadogenesis is most likely at the interface of the updraft and rear flank downdraft, and requires a balance between the outflow and inflow.

Only wall clouds that rotate spawn tornadoes, and they usually precede the tornado between five and thirty minutes. Rotating wall clouds may be a visual manifestation of a low-level mesocyclone. Barring a low-level boundary, tornadogenesis is highly unlikely unless a rear flank downdraft occurs, which is usually visibly evidenced by evaporation of cloud adjacent to a corner of a wall cloud. A tornado often occurs as this happens or shortly afterwards; first, a funnel cloud dips and in nearly all cases by the time it reaches halfway down, a surface swirl has already developed, signifying a tornado is on the ground before condensation connects the surface circulation to the storm. Tornadoes may also develop without wall clouds, under flanking lines and on the leading edge. Spotters watch all areas of a storm, and the cloud base and surface.

Extremes
The tornado which holds most records in history was the Tri-State Tornado, which roared through parts of Missouri, Illinois, and Indiana on March 18, 1925. It was likely an F5, though tornadoes were not ranked on any scale in that era. It holds records for longest path length (219 mi), longest duration (about 3.5 hours), and fastest forward speed for a significant tornado (73 mph) anywhere on Earth. In addition, it is the deadliest single tornado in United States history (695 dead). The tornado was also the costliest tornado in history at the time (unadjusted for inflation), but in the years since has been surpassed by several others if population changes over time are not considered. When costs are normalized for wealth and inflation, it ranks third today.

The deadliest tornado in world history was the Daultipur-Salturia Tornado in Bangladesh on April 26, 1989, which killed approximately 1,300 people.

One of the most extensive tornado outbreaks on record was the 1974 Super Outbreak, which affected a large area of the central United States and extreme southern Ontario on April 3 and 4, 1974. The outbreak featured 148 tornadoes in 18 hours, many of which were violent; seven were of F5 intensity, and twenty-three peaked at F4 strength. Sixteen tornadoes were on the ground at the same time during its peak. More than 300 people, possibly as many as 330, were killed.

While direct measurement of the most violent tornado wind speeds is nearly impossible, since conventional anemometers would be destroyed by the intense winds and flying debris, some tornadoes have been scanned by mobile Doppler radar units, which can provide a good estimate of the tornado's winds. The highest wind speed ever measured in a tornado, which is also the highest wind speed ever recorded on the planet, is 301 ± 20 mph (484 ± 32 km/h) in the F5 Bridge Creek-Moore, Oklahoma, tornado which killed 36 people. The reading was taken about 100 ft above the ground.

Storms that produce tornadoes can feature intense updrafts, sometimes exceeding 150 mi/h. Debris from a tornado can be lofted into the parent storm and carried a very long distance. A tornado which affected Great Bend, Kansas, in November 1915, was an extreme case, where a "rain of debris" occurred 80 mi from the town, a sack of flour was found 110 mi away, and a cancelled check from the Great Bend bank was found in a field outside of Palmyra, Nebraska, 305 mi to the northeast. Waterspouts and tornadoes have been advanced as an explanation for instances of raining fish and other animals.

Safety
Though tornadoes can strike in an instant, there are precautions and preventative measures that can be taken to increase the chances of survival. Authorities such as the Storm Prediction Center in the United States advise having a pre-determined plan should a tornado warning be issued. When a warning is issued, going to a basement or an interior first-floor room of a sturdy building greatly increases chances of survival. In tornado-prone areas, many buildings have underground storm cellars, which have saved thousands of lives.

Some countries have meteorological agencies which distribute tornado forecasts and increase levels of alert of a possible tornado (such as tornado watches and warnings in the United States and Canada). Weather radios provide an alarm when a severe weather advisory is issued for the local area, mainly available only in the United States. Unless the tornado is far away and highly visible, meteorologists advise that drivers park their vehicles far to the side of the road (so as not to block emergency traffic), and find a sturdy shelter. If no sturdy shelter is nearby, getting low in a ditch is the next best option. Highway overpasses are one of the worst places to take shelter during tornadoes, as the constricted space can be subject to increased wind speed and funneling of debris underneath the overpass.

Myths and misconceptions
Folklore often identifies a green sky with tornadoes, and though the phenomenon may be associated with severe weather, there is no evidence linking it specifically with tornadoes. It is often thought that opening windows will lessen the damage caused by the tornado. While there is a large drop in atmospheric pressure inside a strong tornado, the pressure difference is unlikely to cause significant damage. Opening windows may instead increase the severity of the tornado's damage. A violent tornado can destroy a house whether its windows are open or closed. Another commonly held misconception is that highway overpasses provide adequate shelter from tornadoes. This belief is partly inspired by widely circulated video captured during the 1991 tornado outbreak near Andover, Kansas, where a news crew and several other people took shelter under an overpass on the Kansas Turnpike and safely rode out a tornado as it passed nearby. However, a highway overpass is a dangerous place during a tornado, and the subjects of the video remained safe due to an unlikely combination of events: the storm in question was a weak tornado, the tornado did not directly strike the overpass, and the overpass itself was of a unique design. Due to the Venturi effect, tornadic winds are accelerated in the confined space of an overpass. Indeed, in the 1999 Oklahoma tornado outbreak of May 3, 1999, three highway overpasses were directly struck by tornadoes, and at each of the three locations there was a fatality, along with many life-threatening injuries. By comparison, during the same tornado outbreak, more than 2,000 homes were completely destroyed and another 7,000 damaged, and yet only a few dozen people died in their homes.

An old belief is that the southwest corner of a basement provides the most protection during a tornado. The safest place is the side or corner of an underground room opposite the tornado's direction of approach (usually the northeast corner), or the central-most room on the lowest floor. Taking shelter in a basement, under a staircase, or under a sturdy piece of furniture such as a workbench further increases the chances of survival.

There are areas which people believe to be protected from tornadoes, whether by being in a city, near a major river, hill, or mountain, or even protected by supernatural forces. Tornadoes have been known to cross major rivers, climb mountains, affect valleys, and have damaged several city centers. As a general rule, no area is safe from tornadoes, though some areas are more susceptible than others.

Ongoing research
Meteorology is a relatively young science and the study of tornadoes is newer still. Although researched for about 140 years and intensively so for around 60 years, there are still aspects of tornadoes which remain a mystery. Meteorologists have a fairly good understanding of the development of thunderstorms and mesocyclones, and the meteorological conditions conducive to their formation. However, the step from supercell, or other respective formative processes, to tornadogenesis and the prediction of tornadic vs. non-tornadic mesocyclones is not yet well known and is the focus of much research.

Also under study are the low-level mesocyclone and the stretching of low-level vorticity which tightens into a tornado, in particular, what are the processes and what is the relationship of the environment and the convective storm. Intense tornadoes have been observed forming simultaneously with a mesocyclone aloft (rather than succeeding mesocyclogenesis) and some intense tornadoes have occurred without a mid-level mesocyclone.

In particular, the role of downdrafts, particularly the rear-flank downdraft, and the role of baroclinic boundaries, are intense areas of study.

Reliably predicting tornado intensity and longevity remains a problem, as do details affecting characteristics of a tornado during its life cycle and tornadolysis. Other rich areas of research are tornadoes associated with mesovortices within linear thunderstorm structures and within tropical cyclones.

Meteorologists still do not know the exact mechanisms by which most tornadoes form, and occasional tornadoes still strike without a tornado warning being issued. Analysis of observations including both stationary and mobile (surface and aerial) in-situ and remote sensing (passive and active) instruments generates new ideas and refines existing notions. Numerical modeling also provides new insights as observations and new discoveries are integrated into our physical understanding and then tested in computer simulations which validate new notions as well as produce entirely new theoretical findings, many of which are otherwise unattainable. Importantly, development of new observation technologies and installation of finer spatial and temporal resolution observation networks have aided increased understanding and better predictions.

Research programs, including field projects such as the VORTEX projects (Verification of the Origins of Rotation in Tornadoes Experiment), deployment of TOTO (the TOtable Tornado Observatory), Doppler on Wheels (DOW), and dozens of other programs, hope to solve many questions that still plague meteorologists. Universities, government agencies such as the National Severe Storms Laboratory, private-sector meteorologists, and the National Center for Atmospheric Research are some of the organizations very active in research; with various sources of funding, both private and public, a chief entity being the National Science Foundation. The pace of research is partly constrained by the number of observations that can be taken; gaps in information about the wind, pressure, and moisture content throughout the local atmosphere; and the computing power available for simulation.

Solar storms similar to tornadoes have been recorded, but it is unknown how closely related they are to their terrestrial counterparts.

title: Tornado


text:
Talk:Alfa Romeo

Dispute on Alfa Romeo current luxury definition
A dispute is ongoing about a long standing definition of Alfa Romeo as a luxury car manufacturer. While surely this has been true in the past, and even most evident about the definition of sport car manufacturer, the current production suggests a different evidence for the time being. Current models can be viewed on the official website ww.alfaromeo.com : four models are available, 1 is an entry level (Junior), 2 are SUVs (Tonale, Stelvio), 1 is sedan (Giulia). While Stelvio may reasonably fall under the luxury definition, along with the upgraded Quadrifoglio version of Giulia, Junior, Tonale and entry-level Giulia are not.

The "luxury" definition does not apply according several objective metrics. 1: Choice of luxury vehicles in the catalogue. A "luxury brand" should focus the majority of the production on luxury cars. Junior, Tonale and Giulia are not. Please check on the correspondent Wikipedia pages about the general definitions of these models. 2: Technology. A luxury item is not supposed to share the majority of components with entry/compact SUV level items. Two out of six models are definitively no luxury cars. The Junior model has the same chassis of Peugeot 3008; Tonale is a compact SUV derived from Jeep Liberty and shares a modified platform with Jeep Compass (see corresponding entries). 3: Price. A comparative analysis of competitors shows that the luxury segments has higher prices than same-class Alfa Romeo models. For example, BMW 3-series and Mercedes-Benz C-class are in the same segment of Giulia are priced more than Alfa Romeo cars with matching engine and equipment. All manufacturers are from European Union, with similar country-adjusted purchase power. Current sale prices can be verified on official websites. 4: The production of competitors defined as "luxury" manufacturers on Wikipedia offer the majority of their catalogue in the segment of high-value cars (Mercedes-Benz, BMW, Aston Martin, Maserati etc.). As from previous point, the top sedan Alfa Romeo matches the BMW and Mercedes-Benz medium segment. Even if the Quadrifoglio version of Giulia may fall under a "luxury" definition, please notice that this is just an upgraded version, similar for M versions in BMW. 5: Conversely, the luxury definition is not applied on Wikipedia for other manufacturers, even if they offer luxury models comparable to Junior, Tonale, and Giulia by performance, equipment, and price. E.g., Toyota offers Crown and Mirai with reasonable matching features. Moreover, the Toyota luxury division Lexus is defined as such with a catalogue with all cars in the upper segment (and not one or two like Alfa Romeo). 93.37.212.111 (talk) 01:25, 3 May 2024 (UTC)
 * Please don't restore a contested edit while it is under discussion. Meters (talk) 08:24, 5 May 2024 (UTC)
 * Can you provide anything other than your opinions for your statements? For example, who exactly sets these supposed metrics you are discussing?
 * This article has a source that shows that the Alpha Romeo brand was considered a "luxury division" in 2005, and despite your claim that the Tonale is not a luxury vehicle, Tonale contains a sourced statement that it "is marketed in the premium segment". Meters (talk) 08:36, 5 May 2024 (UTC)
 * Quote "Alfa Romeo has been an iconic Italian luxury and high performance car manufacturer for over 110 years", same as premium sport. Reuters premium brand. YBSOne (talk) 10:50, 5 May 2024 (UTC)
 * I did not give personal statement. There is no established metric to define "luxury cars", and a discussion shall proceed by analogy and proxies.
 * I provided several proxies and comparisons with established "luxury" brands, and I included information about some models deriving from middle-segment models from the same manufacturer group, most notably Tonale.
 * My arguments find ground in corresponding Wikipedia entries.
 * Quoting from Reuters is less than a metric; moreover, Alfa Romeo has never been a luxury make in its roaring years, and it was not their scope either since they focused on the sport features. The luxury brand of Fiat Automobiles in the past was Lancia.
 * I suggest that you provide better metrics, since you find mine arbitrary (in absence of accepted definition), but you have no other argument than relying on old entries.
 * Many readers use Wikipedia to retrieve independent information before buying a vehicle and have a better insight to the brand than reading specialised journals (that have a different scope). The information provided may be truly misleading. 51.252.140.27 (talk) 23:38, 10 May 2024 (UTC)
 * It's not up to Wikipedia editors to decide if Alfa Romeo is a luxury or premium brand. We don't do WP:ORIGINAL RESEARCH or "proceed by analogy and proxies". We report what reliable sources call Alfa Romeo. And we have provided reliable sources that call it a premium or luxury brand. Meters (talk) 23:47, 10 May 2024 (UTC)

license: Creative Commons - Attribution Share-Alike - https://creativecommons.org/licenses/by-sa/4.0/

title: Talk:Alfa Romeo


text:
Indian Institute of Science

The Indian Institute of Science (IISc) is a public, deemed, research university for higher education and research in science, engineering, design, and management. It is located in the southern Indian city of Bangalore, Karnataka. The institute was established in 1909 with active support from Jamsetji Tata and thus is also locally known as the Tata Institute. It was granted a deemed university status in 1958 and recognized as an Institute of Eminence in 2018.

History

After an accidental meeting between Jamsetji Tata and Swami Vivekananda, on a ship in 1893 where they discussed Tata's plan of bringing the steel industry to India, Tata wrote to Vivekananda five years later: "I trust, you remember me as a fellow-traveller on your voyage from Japan to Chicago. I very much recall at this moment your views on the growth of the ascetic spirit in India... I recall these ideas in connection with my scheme of Research Institute of Science for India, of which you have doubtless heard or read."

Impressed by Vivekananda's views on science and leadership abilities, Tata wanted him to guide his campaign. Vivekananda endorsed the project with enthusiasm, and Tata, with the aim of advancing the scientific capabilities of the country, constituted a provisional committee to prepare a plan for setting up of an institute of research and higher education. The committee presented a draft proposal to Viceroy George Curzon on 31 December 1898. Subsequently, Sir William Ramsay, a Nobel Laureate, was called on to propose a suitable place for such an institution who suggested Bangalore as the best location.

The land and other facilities for the institution were donated by Maharaja Krishnaraja Wadiyar IV and Tata. The maharaja donated about 371 acre of land; Tata gave several buildings towards the creation of IISc. The maharaja also granted Rs 5,00,000 towards capital expenditure and Rs 50,000 for annual expense. Nizam Osman Ali Khan also contributed, which amounted to around Rs 3,00,000 over a period of 31 years.

The constitution of the institute was approved by Viceroy Gilbert Elliot-Murray-Kynynmound, and the necessary "vesting order" to enable it to function was signed on 27 May 1909. Early in 1911, the maharaja laid the foundation stone of the institute, and on 24 July, the first batch of students were admitted to the Departments of General and Applied Chemistry under Norman Rudolf and Electro-Technology under Alfred Hay. Within two months, the Department of Organic Chemistry was opened. In 1958, the institute was deemed a university by the University Grants Commission of India.

At the time of the inception of IISc in 1909, Morris Travers, Sir William Ramsay's co-worker in the discovery of the noble gases, became its first director. For Travers, this was a natural continuation of his work on the institute, since he had played a role in its founding. The first Indian director was the Nobel Laureate Sir C.V. Raman.

The institute was the first to introduce a master's programs in engineering. It has also started integrated doctoral programmes in biological, chemical, physical, and mathematical sciences for natural science graduates.

In 2018, the IISc was one of the first six institutes to be awarded the Institute of Eminence status. In 2019, the IISc launched its brand statement: "Discover and Innovate; Transform and Transcend; Serve and Lead".

In 2022, the IISc received a private donation of 425 crore Indian Rupees, the largest in its history, to establish a postgraduate medical institute.

Bangalore Campus
The IISc campus is located in the north of Bangalore, about 6 kilometres from Bangalore City Railway Station and Kempegowda Bus Station, on the way to Yeshwantpur. The institute is about 30 kilometres southwest of Kempegowda International Airport. A number of other research institutes, Raman Research Institute, Indian Space Research Organisation (ISRO), Wood Research Institute and Central Power Research Institute (CPRI), are close to IISc. Most of these institutes are connected to IISc by a regular shuttle bus service. The campus houses more than 40 departments marked by routes such as the Gulmohar Marga, the Mahogany Marga, the Badami Marga, the Tala Marga, the Ashoka Marga, the Nilgiri Marg, the Silver Oak Marg, the Amra Marga and the Arjuna Marga. The institute is fully residential and is spread over 400 acres of land in the heart of Bangalore city. The campus features six canteens (cafeterias), a gymkhana (gymnasium and sports complex), a football ground and a cricket ground, five dining messes (halls), one multi cuisine restaurant, nine men's and five women's hostels (dormitories), an air strip, a library, two shopping centers and residences of the faculty members and other staff, besides other amenities.

The IISc campus harbours both exotic and indigenous plant species with about 110 species of woody plants. The roads on the campus are named after the dominant avenue tree species.

The architecture of the main building, which today houses the administration and the Faculty Hall, is classical in style, fronted by a grey, handsome tower. In front of it stands the work of Gilbert Bayes, a monument erected in the memory of J. N. Tata. At its feet is an inscription that serves to remind future generations of the generosity of Jamsetji Tata and the persistence with which he worked for the welfare of India. The building, as one of the prominent landmarks of Bangalore, was designed by C. F. Stevens and Company of Bombay in 1912–13.

The buildings for the metallurgy and aerospace departments were designed by the German architect Otto Königsberger in 1940.

Challakere Campus
A second campus is in Challakere, on 1500 acre lot of land. Infrastructure developed here includes the Talent Development Centre, Skill Development Centre funded by HAL under CSR Act, Solar Power Research Center and a Climate Observatory. The Centre for Sustainable Technologies has commenced its activities here under the project "C-BELT" i.e., the Centre for Bio-energy and Low-Carbon Technologies.

Janardhana Swamy, then Member of Parliament from the Chitradurga Lok Sabha as well as a notable alumnus of IISc and Amalan Biswas, then DC of Chitradurga District played significant roles in setting up the IISc's new campus at Challakere. They were instrumental in identifying all the required 1500 acres of land for the new campus, getting the existing building leased from the Sheep Farm, obtaining the various needed approvals from the government, and having the initial funds released from the State.

Academic divisions, departments, and centres
For academic purposes, departments and centres in the institute are broadly assigned to either the Science Faculty or the Engineering Faculty. For administrative purposes (such as faculty recruitment, assessment and promotion), departments and centres are classified into six divisions, each headed by a chairperson. Each department or centre is administered by a chairperson.

The following centres are directly under the director (without a divisional chairman): • Archives and Publication Cell

• Centre for Continuing Education

• Center for Counseling and Support

• Centre for Scientific & Industrial Consultancy

• Centre for Sponsored Schemes and Projects

• Digital Campus and IT Services Office

• J. R. D. Tata Memorial Library

• Office of Communications

• Office of Development and Alumni Affairs

• Office of Research Grants

• Office of Intellectual Property and Technology Licensing

• Office of International Relations

• Skill Development Centre

• Talent Development CentreAutonomous Societies and Centres based in the Institute: • Advanced Bioresidue Energy Technologies Society

• Centre for Brain Research

• Society for Innovation and Development

Post-graduate research programs
Research students constitute more than 60 % of the students on the campus. PhD degrees offered in 40 different disciplines. Research programs leading to doctoral degrees are the main thrust in many departments. The program has a limited amount of course work, essentially to prepare the student to carry out the research, but the main emphasis is on the thesis work. The annual intake of research students is approximately 575 with several candidates sponsored from educational institutions and industries (through External Registration Program).

The Integrated PhD program is designed to offer opportunities to 3-year BSc graduates for pursuing advanced research in areas of biological, chemical, mathematical, and physical Sciences, leading to the PhD degree. In 2024, IISc launched new short courses on Computational Structural Reliability.

Post-graduate coursework programs
The two-year M.Tech. program is available in almost all engineering departments. Most MTech programs have a set of hard core courses specified as an essential requirement whereas students can take rest of the credits from many courses available in their parent or other departments and also do a dissertation work on the topic of their choice.

Master's degrees offered by the institute are classified into two categories: degrees by coursework (M.Tech., M.Mgt., and M.Des.) and degrees by research (M.Tech. research).

The Department of Management Studies offers a Master of Management program exclusively for engineering graduates. The Center for Product Design and Manufacturing offers the Master of Design (M.Des.) course. Started in 1996, the M.Des. program is a two-year, full-time postgraduate program.

In keeping with India's recent National Education Policy (NEP 2020), IISc has launched the Master of Technology (Online) degree program, a fully online program, for practicing engineers and scientists from academic year 2022–2023. The degree program is for professionals who are sponsored by organisations, who already have a BE/BTech/Equivalent degree and wish to upskill or re-skill themselves in streams like Data Science and Business Analytics, Artificial Intelligence, Electronics and Communication Engineering.

The institute has recently announced MSc program in life sciences and chemical sciences starting from academic year of 2022–23. These 2 years master's degree programs consist of foundational and flexible coursework and hands-on laboratory training. The design is aimed to develop experimental skills in advanced techniques for research, leading to an independent thesis research project. Students enrolled in the M Sc programs can personalize their coursework and research projects.

Undergraduate program
An undergraduate program in science for students after Class XII was conceived during the Centenary Celebrations in 2009. The first batch of students was admitted in 2011. The program offers a four-year Bachelor of Science (Research) and a five-year integrated Master of Science course in six disciplines: Biology, Chemistry, Environmental Science, Material Science, Mathematics, and Physics. The course aims at exposing the students to the inter-disciplinary nature in which scientific research is done in many upcoming fields.

A new undergraduate program B.Tech. in Mathematics and Computing seeks to enter a niche area with the aim of producing future leaders who will be at the forefront of research, development, and innovation in futuristic disciplines and next generation technologies that require deep use of mathematics, computer science, and data science.

Admission to the undergraduate programs is through one of five channels: JEE Main, JEE Advanced, NEET, IISER Aptitude Test and KVPY (now phased out).

J. R. D. Tata Memorial Library
Apart from the main library, the institute also has independent departmental libraries. The library moved into the present premises in January 1965, built out of grants provided by University Grants Commission (UGC), in commemoration of the golden jubilee celebrations of the institute in 1959. In 1995, the library was renamed as "J. R. D. Tata Memorial Library". The National Board for Higher Mathematics (NBHM) has recognised this library as Regional Center for Mathematics for the south region and continued to award a special grant towards subscription of Journals in Mathematics.

The annual budget of the library is over Rs. 100 million (almost US$2,500,000) of which subscription towards periodicals alone is about Rs. 90 million. The library currently receives over 1,734 periodical titles, of which 1381 are subscribed, while the remaining titles are received as gratis or on an exchange basis. About 600 titles are accessible through the library subscription. In addition, over 10,000 journals are accessible online, thanks to INDEST subscription. The total holdings of the library exceed 411,000 documents.

Central computing facility
The Computer Centre, established in 1970 as a central computing facility, became Supercomputer Education and Research Centre (SERC) in 1990 to provide computing facility to the faculty and students of the institute. SERC was created and fully funded by the Ministry of Human Resource Development (MHRD), Government of India to commemorate the platinum jubilee of the institute. It houses India's first petascale supercomputer Cray XC40, the erstwhile fastest supercomputer in India.

Apart from functioning as a central computing facility of IISc, the SERC is engaged in education and research programs in areas relating to supercomputer development and application. The centre is also involved in several sponsored research projects in collaboration with several high-profile government and private agencies.

Academic and industrial collaborations
The Indian Institute of Science collaborates with various government organisations like the Indian Ordnance Factories, DRDO, the ISRO, Bharat Electronics Limited, Aeronautical Development Agency, National Aerospace Laboratories, CSIR, Department of IT (Government of India), Centre for Development of Advanced Computing, etc. IISc also works in collaboration with private industry and research labs. A few organisations have been incubated by the Society for Innovation and Development (SID) on campus, including Morphing Machines and SandI, while Gamma Porite is currently under incubation. IISc actively promotes and supports ventures by the faculty, the students and alumni. Strand Life Sciences and Ittiam are some success stories of this initiative. In March 2016, a science start-up, incubated at the IISc, built the world's first food-grade DNA/RNA stain. This might cut the time taken to diagnose conditions such as HIV to a day, from 45 days at present.

Rankings
Internationally, IISc was ranked 155th in the world and 52nd in Asia in the QS World University Rankings of 2023. IISc had ranked 1st in 2022 in terms of citations per faculty by QS World University Rankings, moreover, IISc had ranked 2nd consistently for more than 5 years among all universities around the world in terms of citations per faculty. It was ranked 251–300 in the world in 2023, 42nd in Asia, and 18 among emerging economies universities in 2022 by the Times Higher Education World University Rankings. It was ranked 301–400 in the world in 2022 by the Academic Ranking of World Universities.

IISc was also ranked 2nd in the overall category, 1st among research institutions, 1st among universities in India by the National Institutional Ranking Framework (NIRF) in 2023. IISc was ranked 2nd in the India in the QS World University Rankings of 2020. Outlook India ranked IISc 1st among universities in 2020.

Events
Pravega is the annual science, technology and cultural festival of Indian Institute of Science, Bangalore. Started in 2013 by the undergraduates of IISc, the fest is usually held on the third weekend of January. Vijyoshi, an annual national science camp for secondary school and undergraduate students, is hosted by IISc.

IISc also has active sports teams, major ones being in cricket, football, badminton and volleyball. They participate each year in the IISM (inter IISER sports meet) and a number of other tournaments and events.

Alumni associations
IISc has a parent alumni association (AA) in Bangalore and several branches elsewhere including USA (IISCAANA). Of recent parent association is involved in several disputes. One of the reasons appears to be efforts by some to allow Non-IISc degree holders to become a part of the AA. Similar situation is created in IISCAANA by allowing several non-IISc members to be active in the team. IIScAANA allows those who did not complete degree to become members by adding a clause 'completed at least one semester of course work in IISc' for membership eligibility.

Music Club
The oldest and currently active music club of IISc.

Rhythmica members are students of IISc (Undergraduate, Masters and PhD) as well as professors.

IISc also hosts a local branch of the Society for the Promotion of Indian Classical Music and Culture Amongst Youth (SPIC MACAY) that was started around 1984.

December 2005 terror attack
On 28 December 2005, two terrorists started firing indiscriminately inside the IISc campus. Munish Chander Puri, a professor from IIT Delhi, died in the attack. Four others were injured.

Notable alumni
• V. K. Aatre

• Anuranjan Anand

• Satya N. Atluri

• Narayanaswamy Balakrishnan

• Siva S. Banda

• Sasanka Chandra Bhattacharyya

• Tavarekere Kalliah Chandrashekar

• Vadapalli Chandrasekhar

• Dipankar Chatterji

• Rajagopala Chidambaram

• Sanjeev Das

• H. G. Dattatreya

• Sukh Dev

• Sanjeev Galande

• S. Ganesh

• N. Gautham

• Rajesh Sudhir Gokhale

• Kunchithapadam Gopalan

• Prashant Goswami

• G. Guruswamy

• Kota Harinarayana

• Rangachar Narayana Iyengar

• A. M. Jayannavar

• Ritu Karidhal

• P. K. Kelkar

• Mohammad Islam Khan

• A. S. Kiran Kumar

• Tapas Kumar Kundu

• Pinaki Majumdar

• Debasisa Mohanty

• Saraju Mohanty

• Jarugu Narasimha Moorthy

• M. R. N. Murthy

• Budaraju Srinivasa Murty

• Sudha Murty

• Ramakrishnan Nagaraj

• Ganesh Nagaraju

• Vinay K. Nandicoori

• P. T. Narasimhan

• Shamkant Navathe

• Sethuraman Panchanathan

• Swapan Kumar Pati

• Aloke Paul

• Beena Pillai

• Thalappil Pradeep

• Balaji Prakash

• Ram Rajasekharan

• Madan Rao

• Gundabathula Venkateswara Rao

• D. Srinivasa Reddy

• Rajendra Prasad Roy

• R. Sankararamakrishnan

• V. K. Saraswat

• Sagar Sengupta

• K. Sivan

• R. Sowdhamini

• K. R. Sreenivasan

• Sargur Srihari

• Narayanaswamy Srinivasan

• S. Somanath

• P. S. Subramanyam

• Janardhana Swamy

• H. V. Thulasiram

• Sitaram Rao Valluri

• M. Vijayan

• P. N. Vinayachandran

• Rajindar Pal Wadhwa

Notable faculty
Two former directors, C. V. Raman and C. N. R. Rao, have been awarded India's highest civilian honour Bharat Ratna. Four former directors, Sir A. G. Bourne, Sir Martin O. Forster, C. V. Raman and J. C. Ghosh, have been knighted. Among the IISc alumni, there are three Rhodes Scholars, several Fellows of the Royal Society, and thousands of members of Indian and foreign Academy of Sciences. Hundreds of IISc faculty members have also received the Shanti Swarup Bhatnagar Prize for Science and Technology awarded to Indians who have made outstanding contributions under 45 years of age. In spite of these achievements, no alumnus or serving faculty member of IISc has won either a Nobel Prize or a Fields Medal, although C. V. Raman did win a Nobel Prize before becoming the institute's first Indian director.

• Perdur Radhakantha Adiga

• P. Balaram

• Dipankar Banerjee

• Ganapati Shankar Bhat

• Santanu Bhattacharya

• Vivek Borkar

• Tushar Kanti Chakraborty

• Akhil Ranjan Chakravarty

• Dipshikha Chakravortty

• Nagasuma Chandra

• Jayaraman Chandrasekhar

• Srinivasan Chandrasekaran

• Kamanio Chattopadhyay

• Atul Chokshi

• Saumitra Das

• Devadas Devaprabhakara

• Patrick D'Silva

• K. R. K. Easwaran

• Gilbert John Fowler

• Rohini Godbole

• Balasubramanian Gopal

• Narayanaswamy Jayaraman

• Chanda Jog

• Kaushal Kishore (scientist)

• H. R. Krishnamurthy

• Anurag Kumar

• Narendra Kumar (physicist)

• Rajinder Kumar (chemical engineer)

• Viswanathan Kumaran

• Uday Maitra

• Neelesh B. Mehta

• Pramod Sadasheo Moharir

• Nuggehalli Raghuveer Moudgal

• Govindasamy Mugesh

• Partha Sarathi Mukherjee

• Manohar Lal Munjal

• Kalappa Muniyappa

• V. Nagaraja

• Ramarathnam Narasimhan

• Roddam Narasimha

• Rishikesh Narayanan

• Dorothy Norris

• R. V. Norris

• Apoorva D. Patel

• Patrick D'Silva

• Aloke Paul

• Sunil Kumar Podder

• E. S. Raja Gopal

• Ashok M. Raichur

• Vaidyeswaran Rajaraman

• G. N. Ramachandran

• Subramaniam Ramakrishnan

• C.V. Raman

• Suryanarayanasastry Ramasesha

• Sivaraj Ramaseshan

• Sriram Ramaswamy

• P. N. Rangarajan

• Srinivasan Sampath

• Kalya Jagannath Rao

• C. N. R. Rao

• N. Ravishankar

• Dipankar Das Sarma

• V. Sasisekharan

• S. K. Satheesh

• K. Sekar

• Vijay Balakrishna Shenoy

• Amit Singh

• Aninda Sinha

• Krityunjai Prasad Sinha

• K. Sivan

• Kumaravel Somasundaram

• Ajay Sood

• Adusumilli Srikrishna

• G. S. R. Subba Rao

• Utpal S. Tatu

• Sundaram Thangavelu

• Siva Umapathy

• Giridhar Madras

• Raghavan Varadarajan

• Sudhir Kumar Vempati

• M. Vijayan

• P. N. Vinayachandran

• Sandhya Srikant Visweswariah

• S. P. Chakravarti

• S. Dhawan

• V. M. Ghatage

• G. K. Ananthasuresh

title: Indian Institute of Science