The atmosphere of Jupiter is the largest planetary atmosphere in the Solar System. Most are made of hydrogen and helium molecules in the proportion of rough sun; Other chemical compounds exist only in small amounts and include methane, ammonia, hydrogen sulphide and water. Although water is considered far away in the atmosphere, the direct measured concentrations are very low. The abundance of nitrogen, sulfur, and noble gases in Jupiter's atmosphere exceeds solar values ​​by a factor of about three.
The atmosphere of Jupiter does not have a clear lower boundary and gradually transitions into the liquid interior of the planet. From the lowest to the highest, the atmospheric layer is the troposphere, the stratosphere, the thermosphere, and the exosphere. Each layer has a characteristic temperature gradient. The lowest layer, the troposphere, has an intricate cloud and fog system, composed of layers of ammonia, ammonium hydrosulfide, and water. The upper ammonia cloud is visible on the surface of Jupiter which is set in a dozen zonal bands parallel to the equator and is limited by the flow of a strong zonal atmosphere (wind) known as jet . Bands alternate colors: dark bands are called belts , while light ones are called zones . The zone, which is colder than the belt, corresponds to the upwellings, while the belt marks the gas down. Lightweight zones are believed to come from ammonia ice; what gives their dark color belt is uncertain. The origins of structures and jet stuttering are not well understood, although "superficial models" and "deep models" exist.
The Jovian atmosphere shows various active phenomena, including band instability, vortices (cyclones and anticyclones), storms and lightning. Vorticity manifests itself as a large red, white or brown (oval) spots. The two biggest points are the Great Red Spot (GRS) and Oval BA, which are also red. The second and most of the other large spots are anticillonic. Smaller anticyclones tend to be white. Vortex is considered a relatively shallow structure with depth not exceeding several hundred kilometers. Located in the southern hemisphere, GRS is the largest vortex known in the Solar System. It can swallow two or three Earths and has existed for at least three hundred years. Oval BA, south of GRS, is the red dot of one-third the size of GRS that was formed in 2000 from the merging of three white ovals.
Jupiter has a strong storm, often accompanied by lightning strikes. Storms are the result of wet convection in the atmosphere connected with evaporation and water condensation. They are the site of a strong upward motion of air, which leads to the formation of bright and dense clouds. Storms form mainly in the belt region. Lightning attacks in Jupiter are hundreds of times stronger than those seen on Earth, and are assumed to be associated with water clouds. This storm near the red dot is called Red Spot Junior.
Video Atmosphere of Jupiter
Struktur vertikal
Jupiter's atmosphere is classified into four layers, by increasing altitudes: the troposphere, the stratosphere, the thermosphere and the exosphere. Unlike Earth's atmosphere, Jupiter has no mesosphere. Jupiter does not have a solid surface, and the lowest layer of the atmosphere, the troposphere, transitions smoothly into the planet's liquid interior. This is the result of having temperature and pressure well above the critical points for hydrogen and helium, which means that there is no sharp boundary between the gas phase and the liquid phase. Hydrogen becomes a supercritical fluid at a pressure of about 12 bar.
Since the lower limit of the atmosphere is unclear, the pressure level of 10 bar, at an altitude of about 90 km below 1 bar with a temperature of about 340 ° K, is usually treated as the base of the troposphere. In scientific literature, the pressure level of bar 1 is usually chosen as a zero point for height - Jupiter's "surface". Like Earth, the uppermost atmospheric layer, the exosphere, does not have a well-defined upper bound. The density gradually decreases until smoothly transitions to interplanetary medium about 5,000 km above the "surface".
The vertical temperature gradient in the Jovian atmosphere is similar to Earth's atmosphere. The troposphere temperatures decrease with height to a minimum in the tropopause, which is the boundary between the troposphere and the stratosphere. In Jupiter, the tropopause is about 50 km above the visible cloud (or 1 bar level), where the pressure and temperature are about 0.1 bar and 110Ã,  ° C. In the stratosphere, the temperature rises to about 200Ã, ° K at transition to the thermosphere, at altitudes and pressures of about 320 km and 1 bar. In the thermosphere, the temperature continues to rise, eventually reaching 1000 K at about 1000 km, where the pressure is about 1 nbar.
Jupiter's troposphere contains complex cloud structures. The upper cloud, which lies in the pressure range from 0.6 to 0.9 bar, is made of ammonia ice. Under this ammonia ice cloud, solid clouds are made of ammonium hydrosulfide ((NH 4 ) SH) or ammonium sulfide (< S, between 1-2Ã, bar) and water (3-7Ã, bar) are considered to exist. There is no methane cloud because the temperature is too high to condense. Clouds form the most dense layers of clouds and have the strongest influence on atmospheric dynamics. This is the result of higher water condensation and higher water abundance compared to ammonia and hydrogen sulfide (oxygen is a more abundant chemical element than nitrogen or sulfur). The various troposphere (at 200-500 mbar) and the stratospheric fog layer (at 10-100 mbar) are above the main cloud layer. The latter is made of heavy polycyclic aromatic hydrocarbons or hydrazine, which are generated in the upper stratosphere (1-100Ã,? Bar) of methane under the influence of ultraviolet solar (UV) radiation. The relative abundance of methane to hydrogen molecules in the stratosphere is about 10 -4 , whereas the ratio of other light hydrocarbon abundances, such as ethane and acetylene, to molecular hydrogen is about 10 -6 .
Jupiter thermosphere lies at a pressure lower than 1 bar and shows phenomena such as airglow, polar aurorae and X-ray emission. In it there is a layer of electron increase and ion density that make up the ionosphere. The high temperatures prevalent in the thermosphere (800-1000 K) have not been fully explained; existing models predict temperatures not higher than about 400 ° C. They may be caused by the absorption of high-energy solar radiation (UV or X-ray), by heating from charged particles that precipitate from the Jovian magnetosphere, or by dissipating upward- gravitational waves. The atmospheric and exosphere at the poles and at low latitudes emit X rays, which were first observed by the Einstein Observatory in 1983. The energetic particles derived from Jupiter's magnetosphere create a bright oval aurora, which surrounds the poles. Unlike their terrestrial analogs, which appear only during a magnetic storm, the aurora is a permanent feature of Jupiter's atmosphere. Thermosphere is the first place outside the Earth where the cation trihidrogen ( H 3 ) found. This ion radiates strongly in the middle of the infrared spectrum, at wavelengths between 3 and 5 m; this is the main cooling mechanism of the thermosphere.
Maps Atmosphere of Jupiter
Chemical composition
Jupiter's atmospheric composition is similar to the planet's overall atmosphere. The atmosphere of Jupiter is the most comprehensively understood of all the gas giants as it is observed directly by the atmospheric probe of Galileo when it enters the Jovian atmosphere on December 7, 1995. Other sources of information about Jupiter's atmosphere The composition includes the Infrared Space Observatory (ISO), Galileo orbiter > and Cassini , and Earth-based observations.
The two main constituents of the Jovian atmosphere are the hydrogen molecules ( H
2 ) and helium. The abundance of helium is 0.157 Â ± 0.004 relative to molecular hydrogen by the number of molecules, and the mass fraction is 0.234 Â ± 0.005 , which is slightly lower than the primordial Solar System value. The reason for this low abundance is not fully understood, but some helium may be condensed into the core of Jupiter. This condensation may be in the form of helium rain: as hydrogen turns into a metallic state at a depth of more than 10,000 km, helium separates from it forming droplets which, becoming denser than the metallic hydrogen, descend towards the nucleus. It may also explain the decrease in fluorescent weight (see Table), an element that is easily soluble in helium droplets and will be transported in it to the nucleus as well.
The atmosphere contains various simple compounds such as water, methane (CH 4 ), hydrogen sulfide (H 2 S), ammonia (NH 3 ) and phosphine (PH 3 ). Their abundance in the troposphere (below 10 bar) implies that Jupiter's atmosphere is enriched in carbon, nitrogen, sulfur and possibly oxygen elements by a factor of 2-4 relative to the Sun. The noble gases argon, krypton and xenon also appear in abundance relative to the sun's level (see table), while neon is rare. Other chemical compounds such as arsine (AsH 3 ) and germane (GeH 4 ) exist only in trace amounts. The upper atmosphere Jupiter contains small amounts of simple hydrocarbons such as ethane, acetylene, and diacetylene, which are formed from methane under the influence of solar ultraviolet radiation and charged particles derived from Jupiter's magnetosphere. Carbon dioxide, carbon monoxide and water in the upper atmosphere are thought to come from impacting comets, such as Shoemaker-Levy 9. Water can not come from the troposphere because the cold tropopause acts like a cold trap, effectively preventing water from rising. to the stratosphere (see Vertical structure above).
Earth-based measurements and spacecraft have increased knowledge of the isotopic ratios in Jupiter's atmosphere. In July 2003, the value received for deuterium abundance was 2.25 Â ± 0.35Ã,ÃÆ' â € "10 -5 , which may represent a primordial value in the protosolar nebula which gave birth to the Solar System. The ratio of nitrogen isotopes in the Jovian atmosphere, 15 N to 14 N, is 2.3 ÃÆ'â € "10 -3 , a third lower than it's in Earth's atmosphere (3.5 ÃÆ' â € "10 -3 ). This latter discovery is highly significant because the previous theory of the formation of the Solar System considers the terrestrial value for the nitrogen isotope ratio to be primordial.
Zones, belts and jets
Jupiter's visible surface is divided into several bands parallel to the equator. There are two types of bands: colored colored and a relatively dark belt . The broader Equatorial Zone (EZ) extends between latitudes around 7Ã, Â ° S to 7Ã, Â ° LU. Above and below the EZ, the North and South Equatorial belts (NEB and SEB) extend to 18 Â ° N and 18 Â ° C, respectively. Further away from the equator lies North and South Tropical zones (NtrZ and STrZ). The alternating pattern of belts and zones continues until the polar region is around 50 degrees latitude, where the appearance of the visible becomes slightly muted. The basic structure of the belt-zone may extend well toward the poles, reaching at least 80 ° North or South.
The difference in appearance between zones and belts is caused by differences in cloud opacity. The ammonia concentration is higher in the zone, which leads to the appearance of thick clouds of ammonia ice at higher altitudes, which in turn leads to lighter shades. On the other hand, in the belt clouds are thinner and located at lower altitudes. The upper troposphere is cooler in the zone and warmer on the belt. The exact chemical properties that make the Jovian zones and bands very colorful are unknown, but they may include complicated compounds of sulfur, phosphorus and carbon.
Jovian bands are limited by the flow of zonal atmosphere (wind), which is called jet . The east jet (prograde) is found on the transition from zone to belt (away from the equator), while the jet to the west (retrograde) marks the transition from belt to zone. This pattern of flow velocity means that zonal winds are decreasing on the belt and increasing the zones from the equator to the poles. Therefore, the wind shear in the belt is cyclone, while in the zone it is anticyclonic. EZ is an exception to this rule, showing a strong jet to the east (prograde) and has a minimum local wind speed right at the equator. High jet speed in Jupiter, reaching over 100 m/s. This velocity corresponds to the ammonia clouds located at a pressure range of 0.7-1 bar. The prograde jets are generally more powerful than the retrograde jets. The jet vertical level is unknown. They decay more than two to three altitude scales above the clouds, while below the cloud level, the wind increases slightly and then remains constant to at least 22 bar - the maximum operational depth achieved by Galileo Probe.
The origin of the Jupiter bandung structure is not entirely clear, though it may be similar to the one that propelled the Hadley cell on Earth. The simplest interpretation is that the zone is a place of upwelling the atmosphere, whereas the belt is a manifestation of downwelling. When the enriched air in the ammonia rises in the zone, it expands and cools, forming a high, dense cloud. However, in the belt, the air descends, adiabatically warming as in the zone of convergence on Earth, and the white ammonia clouds evaporate, revealing lower and darker clouds. The location and width of the band, the speed and location of jets in Jupiter are very stable, only slightly changed between 1980 and 2000. One example of change is the strongest east jet velocity degradation located at the border between North Tropical zone and North Temperature belt at 23 Â ° N However bands vary in color and intensity over time (see below). This variation was first observed in the early seventeenth century.
Special band
The belts and zones that divide the atmosphere of Jupiter each have their own unique names and characteristics. They begin under the North and South Polar Regions, which extend from the poles to about 40-48 Â ° N/S. This bluish gray area usually lacks properties.
The North North Temperate Region rarely shows more detail than the polar regions, due to leg embrittlement, foreshortening, and general feature flexibility. However, the North-North Temperature Belt (NNTB) is the northernmost belt, though it is sometimes lost. Disorders tend to be small and short-lived. The North-North Temperate Zone (NNTZ) may be more prominent, but also generally quiet. Small belts and other small zones in the region are sometimes observed.
The North Temperate Region is part of the easily observable latitudinal region of the Earth, and thus has an outstanding observational record. It also has the strongest progressive jet stream on the planet - the western currents forming the southern boundary of the Northern Temperature Belt (NTB). NTB fades roughly once in a decade (this is the case during the Voyager encounter ), making the Northern Temperature Zone (NTZ) seem to merge into the North Tropical Zone (NTropZ). At other times, NTZ is divided by a narrow belt to the north and south components.
The North Tropical Area consists of NTropZ and the Northern Equatorial Belt (NEB). NTropZ is generally stable in coloration, changing color only in tandem with activity in the south jet stream of NTB. Like NTZ, it's also sometimes shared by narrow bands, NTropB. On rare occasions, NTropZ south plays host to "Little Red Spot". As the name implies, this is the northern equivalent of the Great Red Spot. Unlike the GRS, they tend to occur in pairs and are always short-lived, surviving an average year; one was present during the Pioneer 10 meeting.
NEB is one of the most active belts on the planet. It is characterized by white anticyclonic ovals and cyclone "barges" (also known as "brown oval"), with the former usually forming further north than the last; like in NTropZ, most of these features are relatively short-lived. Like the South Equatorial Belt (SEB), the NEB sometimes fades dramatically and "lives again". The time scale of this change is about 25 years.
The Equatorial Region (EZ) is one of the most stable regions on the planet, in latitude and activity. The northern edge of EZ approached the spectacular clumps southwest of the NEB, bordered by a dark, warm (infrared) feature known as festoons (hot spots). Although the southern boundary of EZ is usually silent, observations from late 19th to early 20th century show that this pattern is then reversed relative to today. EZ varies in color, from pale to ocher color, or even copper; sometimes divided by Equatorial Band (EB). Features in EZ move about 390 km/h relative to other latitude.
The Southern Tropical Area includes the Southern Equatorial Belt (SEB) and the South Tropical Zone. It is the most active region on the planet, as it is home to the strongest retrograde jet stream. SEB is usually the widest and darkest belt in Jupiter; sometimes split by zones (SEBZ), and can fade completely every 3 to 15 years before reappearing in what is known as the SEB Revival cycle. A few weeks or months after the loss of the belt, white spots form and erupt dark brownish material that extends into the new belt by Jupiter's wind. The belt recently disappeared in May 2010. Another characteristic of SEB is the long train of cyclone disorders following the Great Red Spot. Like NTropZ, STropZ is one of the most prominent zones on the planet; not only containing GRS, but occasionally hired by South Tropical Disturbance (STropD), a division of a zone that can be very long-lived; the most famous of which lasted from 1901 to 1939.
The South Temperate Region, or South Temperate Belt (STB), is a dark and prominent belt, more than NTB; until March 2000, the most notable feature is the long-lived white oval of BC, DE, and FA, which has since joined to form Oval BA ("Red Jr."). Ovals are part of the South Climate Zone, but they extend to the STB blocking some of it. STB sometimes fades, apparently because of the complex interaction between white ovals and GRS. The rise of South Temperate Zone (STZ) - the zone where white oval is derived - varies greatly.
There are other features in Jupiter that are temporary or difficult to observe from Earth. South South Temperate Region is more difficult to see even than NNTR; the details are subtle and can only be studied well by large telescopes or spacecraft. Many zones and belts are more transient in nature and not always visible. These include Equatorial band (EB), North Equatorial belt borders (NEBZ, white zone within the belt) and South Equatorial belt zone (SEBZ). The belt is also sometimes divided due to sudden disruption. When an interruption divides a normal single-zone belt, an N or S is added to indicate whether its component is north or south; e.g., NEB (N) and NEB (S).
Dynamics
The circulation in Jupiter's atmosphere is very different from that in the Earth's atmosphere. The inside of Jupiter is fluid and has no solid surface. Therefore, convection can occur in all the molecular envelopes outside the planet. In 2008, a comprehensive theory of Jovian atmospheric dynamics has not yet been developed. Such a theory needs to explain the following facts: the existence of stable bands and narrow jets symmetrical relative to the equator Jupiter, the powerful jet prograde observed at the equator, the difference between zones and belts, and the origin and persistence of large vortices. such as the Great Red Spot.
Theories about the dynamics of the Jovian atmosphere can be broadly divided into two classes: shallow and deep. The former argue that the circulation observed is largely confined to the thin (weather) thin layers of the planet, which coat the stable interior. The final hypothesis states that the observed atmospheric flow is only a surface manifestation of deep-rooted circulation outside Jupiter's molecular envelope. Since both theories have their own successes and failures, many planetary scientists think that the true theory will incorporate the elements of both models.
Shallow model
The first attempt to explain the dynamics of the Jovian atmosphere dates back to the 1960s. They were partly based on terrestrial meteorology, which had developed well at the time. Such superficial models assume that jets in Jupiter are driven by small-scale turbulence, which in turn is maintained by wet convection in the outer layer of the atmosphere (above the water cloud). Wet convection is a phenomenon associated with condensation and water evaporation and is one of the main drivers of terrestrial weather. The jet production in this model is related to the well-known property of two-dimensional turbulence - the so-called inverse cascade, in which small turbulent structures (vortices) combine to form larger ones. The limited planet's size means that the cascade can not produce larger structures of some characteristic scale, which for Jupiter is called the Rhines scale. Its existence is connected with the production of Rossby waves. This process works as follows: when the largest turbulent structure reaches a certain size, the energy begins to flow into the Rossby wave instead of the larger structure, and the reverse cascade stops. Since on a rapidly rotating planet rotating dispersion dispersion of Rossby is anisotropic, the Rhines scale in the direction parallel to the equator is greater than the orthogonal direction toward it. The end result of the process described above is the production of large-scale longitudinal structures, parallel to the equator. The level of meridians seems to correspond to the actual width of the beam. Therefore, in the superficial model vortices actually feed the jet and must disappear by joining into it.
While this weather layer model manages to explain the existence of a dozen narrow jets, they have serious problems. The glaring failure of the model is the super-rotating jet of the equator: with some rare exceptions, the superficial model produces a strong retrograde (subrotating) jet, contrary to observation. In addition, jets tend to be unstable and may disappear over time. The superficial model can not explain how atmospheric flow observed in Jupiter violates the stability criteria. The more complex multilayer model of the weather layer results in a more stable circulation, but many problems remain. Meanwhile, Galileo Probe found that the winds in Jupiter extend far below the water clouds at 5-7Ã, bar and show no evidence of decay to a pressure level of 22 bar, which implies that the circulation in the Jovian atmosphere may actually be deep.
Models in
The in-depth model was first proposed by Busse in 1976. The model is based on another well-known feature of fluid mechanics, Taylor-Proudman's theorem. He argues that in a rapidly rotating barotropic ideal fluid, the current is arranged in a series of cylinders parallel to the axis of rotation. The condition of the theorem may be fulfilled in the liquid Jovian interior. Therefore, molecular molecular coat molecules can be divided into cylinders, each cylinder has an independent circulation from the other. The latitudes where the outer and inner cylindrical boundaries are tangent to the visible surface of the planet according to the jet; The cylinder itself is observed as a zone and belt.
The deep model easily explains the powerful jet prograde observed at Jupiter's equator; the resulting jet is stable and does not adhere to the 2D stability criteria. Yet it has great difficulty; this resulted in a very small amount of broadcasts, and the realistic simulation of 3D flow was not possible in 2008, meaning that the simple model used to justify deep circulation may fail to capture the important aspect of fluid dynamics in Jupiter. One model published in 2004 successfully reproduced the Jovian band-jet structure. It is thought that molecular hydrogen mantle is thinner than in all other models; occupying only 10% of the outside of Jupiter's radius. In the standard Jovian interior model, the mantle is made up of 20-30% outside. Driving deep circulation is another matter. The deep flow can be caused either by shallow strength (wet convection, for example) or by convection across the planet that transports heat out of the Jovian interior. Which mechanism is more important is not clear.
Internal heat
As is known since 1966, Jupiter emits more heat than it receives from the Sun. It is estimated that the ratio between the forces emitted by the planets and those absorbed from the Sun is 1.67 Ã, Â ± 0.09 . The internal heat flux of Jupiter is 5.44 Â ± 0.43 W/m 2 , while the total power emitted is 335 Ã, Â ± 26 petawatts . The last value is roughly equal to one billion of the total power radiated by the Sun. This excess heat is primarily primordial heat from the early phase of Jupiter formation, but can result in a portion of the deposition of helium to the nucleus.
Internal heat may be important for Jovian atmospheric dynamics. While Jupiter has a small slope of about 3 Â °, and its poles receive much less solar radiation than the equator, the troposphere temperature does not change appreciably from the equator to the poles. One explanation is that Jupiter's convection interior acts like a thermostat, releasing more heat near the poles than in the equator. This causes a uniform temperature in the troposphere. While heat is transported from the equator to the poles mainly through the atmosphere on Earth, the convection in Jupiter balances heat. Convection in the Jovian interior is expected to be driven primarily by internal heat.
Discrete features
Vortices
The atmosphere of Jupiter is home to hundreds of vortices - a circular spinning structure that, like in Earth's atmosphere, can be divided into two classes: cyclones and anticyclones. The cyclone rotates in the same direction as the planet rotation (counterclockwise in the Northern Hemisphere and clockwise in the south); anticyclones spin in the opposite direction. However, unlike in the terrestrial atmosphere, anticyclones dominate more than cyclones in Jupiter - more than 90% of vortices greater than 2000 km are diameter anticyclones. The life span of Jovian vortices varies from a few days to hundreds of years, depending on the size. For example, the average age of anticyclone between 1,000 and 6000 km in diameter is 1-3 years. Vortices are never observed in the equatorial region of Jupiter (within 10 ° of the latitude), where they are unstable. Like on fast-rotating planets, Jupiter anticyclones are the center of high pressure, while cyclones are low pressure.
Anticyclones in Jupiter's atmosphere are always confined within the zone, where wind speed increases from the equator to the poles. They are usually bright and appear as white ovals. They can move in longitude, but remain around the same latitude because they can not escape from a restricted zone. The wind speed at their periphery is about 100 m/s. Different anticyclones located in one zone tend to join, as they approach each other. But Jupiter has two anticyclones that are somewhat different from the others. They are the Great Red Spot (GRS) and Oval BA; the latter formed only in 2000. In contrast to the white oval, this structure is red, arguably due to the dredging of red material from the depths of the planet. In Jupiter, anticyclones are typically formed through a combination of smaller structures including convective storms (see below), although large ovals can result from jet instability. The latter was observed in 1938-1940, when several white ovals emerged as a result of the instability of the southern temperate zone; they then merge to form Oval BA.
Unlike anticyclones, Jovian cyclones tend to be small, dark and irregular structures. Some of the darker and more regular features are known as brown oval (or badges). But the existence of some large long-lived cyclones has been suggested. In addition to the compact cyclone, Jupiter has some irregular large filamentous fillings, which indicate cyclone rotation. One of them lies to the west of the GRS (in its wake area) in the southern equatorial belt. These patches are called cyclone (CR) regions. Cyclones are always on the belt and tend to blend when they meet each other, like anticyclones.
The deep vortex structure is not entirely clear. They are considered relatively thin, because any thickness greater than about 500 km will cause instability. The great anticyclones are known to extend only a few tens of kilometers above the visible clouds. The initial hypothesis that vortices are convective waves in (or convective columns) in 2008 is not shared by the majority of planetary scientists.
Big Red Spot
The Great Red Spot (GRS) is a persistent anticyclonic storm, 22 Â ° south of the equator of Jupiter; Earth's observations establish a minimum 350-year storm. The storm was described as a "permanent place" by Gian Domenico Cassini after observing the feature in July 1665 with instrument maker Eustachio Divini. According to a report by Giovanni Battista Riccioli in 1635, Leander Bandtius, identified by Riccioli as Dunisburgh Monastery who possessed a "magnificent telescope", observed a large point he described as "oval, equaling the seventh diameter of Jupiter in its longest distance. "According to Riccioli," these features are rarely seen, and then only by telescopes with exceptional quality and enlargement. " The Great Spot has been almost continuously observed since the 1870s.
GRS rotates counter-clockwise, with a period of about six Earth days or 14 days of Jovian. Its dimensions are 24,000-40,000 km east to west and 12,000-14,000 km north-to-south. It's big enough to fit two or three Earth-sized planets. At the beginning of 2004, the Great Red Spot had roughly half of the elongated line that a century ago, when it was 40,000 km in diameter. At the current rate of reduction, potentially circular in 2040, though this is not possible due to the distorting effect of the neighboring jet stream. It is not known how long the place will last, or whether the change is a result of normal fluctuations.
According to a study by scientists at the University of California, Berkeley, between 1996 and 2006 the point loses 15% of its diameter along its key axis. Xylar Asay-Davis, who was on the research team, noted that the point does not disappear because "speed is a stronger measurement because the cloud associated with the Red Point is also strongly influenced by other phenomena in the surrounding atmosphere."
Infrared data has long shown that the Big Red Point is colder (and therefore, higher in height) than most other clouds on the planet; clouds from the GRS about 8 km above the surrounding cloud. Furthermore, tracking atmospheric features carefully showed counter-clockwise circulation as far back as 1966 - the observations were dramatically confirmed by the first time lapse film of the flybys Voyager. This place is spatially limited by a very simple eastward (prograde) north jet stream (retrograde) to the north. Although the winds around the top edge of the place at about 120 m/s (432 km/h), the current inside it looks stagnant, with little entry or exit. The period of spot rotation has decreased over time, perhaps as a direct result of its stable size reduction. In 2010, astronomers modeled the GRS in far infrared (from 8.5 to 24 m) with higher spatial resolution than before and found that its middle region, the faintest of which was warmer than the surrounding area between 3-4 Â ° C. located in the upper troposphere at a pressure range of 200-500 mbar. This warm central point is slowly in opposite directions and may be caused by a weakening of air in the center of the GRS.
The latitude of Great Red Spot has been stable during good observation records, usually varying by about one degree. Its longitude, however, is subject to constant variation. Because Jupiter's visible features do not rotate evenly across all latitudes, astronomers have defined three different systems to define longitude. The II system is used for latitudes over 10 Â °, and is initially based on the average rotation rate of Great Red Spot 9 hours 55m 42s. Nevertheless, the place has 'licked' the planet in System II at least 10 times since the beginning of the 19th century. The rate of deviation has changed dramatically over the years and has been attributed to the Southern Equatorial Belt's brightness, and the presence or absence of Southern Tropical Disorders.
It is not known exactly what caused the reddish color of the Great Red Spot. Theories supported by laboratory experiments assume that color may be caused by complex organic molecules, red phosphorus, or other sulfur compounds. GRS varies greatly in color, from almost red brick to pale salmon, or even white. The higher temperatures of the red center region are the first evidence that Spot colors are influenced by environmental factors. The spot sometimes disappears from the visible spectrum, becoming clear only through the Red Spot Hollow, which is a niche in the South Equatorial Belt (SEB). GRS visibility is apparently combined with the appearance of SEB; When his white belt is light, it tends to be dark, and when it's dark, the dot is usually mild. Periods when dark or light dots occur at irregular intervals; in the 50 years since 1947 to 1997, it was the darkest place in the period 1961-1966, 1968-1975, 1989-1990, and 1992-1993. In November 2014, data analysis from NASA's Cassini mission revealed that red color is probably a product of simple chemicals that are broken down by sunlight in the planet's upper atmosphere.
The Great Red Spot should not be equated with the Great Dark Spot, a feature observed near Jupiter's north pole in 2000 by the Cassini-Huygens spacecraft. A feature in Neptune's atmosphere is also called the Big Dark Spot. The latter feature, imaged by Voyager 2 in 1989, may be an atmospheric hole rather than a storm. It was no longer present in 1994, although similar places have emerged further north.
BA Oval
Oval BA is a red storm in the southern hemisphere of Jupiter similar in shape, though smaller than, the Great Red Spot (often referred to as "Red Spot Jr", "Red Jr" or "The Little Red Spot"). A feature in the South Temperate Belt, BA Oval was first seen in 2000 after the collision of three minor white storms, and has been increasing since then.
The formation of three white oval storms that later merged into Oval BA can be traced to 1939, when the South Temperature Zone is torn by a dark feature that effectively divides the zone into three long sections. Jovian observer Elmer J. Reese labeled the dark parts AB, CD, and EF. The split expands, shrinking the remaining STZ segments into the white ovals of FA, BC, and DE. Oase BC and DE joined in 1998, forming the BE Oval. Then, in March 2000, the BE and FA joined together, forming the BA Oval. (see White oval, below)
Oval BA slowly began to turn red in August 2005. On February 24, 2006, Philippine amateur astronomer Christopher Go discovered the color change, noting that the color had achieved the same color as the GRS. As a result, NASA author Dr Tony Phillips suggested it was called "Red Spot Jr" or "Red Jr"
In April 2006, the team of astronomers, believing that Oval BA might meet with the GRS that year, observed the storm via the Hubble Space Telescope. Storms passed each other every two years, but the journey of 2002 and 2004 did not yield anything interesting. Dr Amy Simon-Miller, from the Goddard Space Flight Center, estimates the storm will experience their closest congestion on July 4, 2006. On July 20, the two storms were photographed by each other by the Gemini Observatory without convergence.
Why Oval BA turns red is not understood. According to a 2008 study by Dr. Santiago PÃÆ' Â © rez-Hoyos of the University of the Basque Country, the most likely mechanism is "an upward and inward diffusion of a colored compound or vapor coating that may interact later with high solar energy, photons at the top level of Oval BA." Some people believe that small storms (and their corresponding white spots) in Jupiter turn red when the wind becomes strong enough to attract certain gases from the deeper atmosphere that change color when the gases are exposed to the sun.
Oval BA is getting stronger according to observations made with Hubble Space Telescope in 2007. Wind speed has reached 618 km/h; almost the same as in the Great Red Spot and much stronger than a progenitor storm. By July 2008, the size was about the diameter of the Earth - roughly half the size of the Big Red Spot.
Oval BA should not be confused with other big storms in Jupiter, South Tropical Little Red Spot (LRS) (nicknamed "Baby Red Spot" by NASA), which was destroyed by GRS. The new storm, formerly a white spot in Hubble's image, was flushed in May 2008. The observation was led by Imke de Pater of the University of California, in Berkeley, USA. Baby Red Spot found GRS in late June to early July 2008, and in a collision, the smaller red dots were torn apart. The remains of the first Baby Red Spot orbit, then then consumed by the GRS. The last of the remains with reddish colors has been identified by astronomers has disappeared in mid-July, and the rest of the pieces again collided with the GRS, then eventually joined the larger storm. The remaining pieces of the Baby Red Spot had completely disappeared in August 2008. During this meeting, BA Oval was present nearby, but did not play any real role in the destruction of the Baby Red Spot.
Storms and lightning
The storm in Jupiter is similar to a storm on Earth. They show themselves through brightly cloudy clouds of about 1000 km in size, which appear from time to time in cyclone belt regions, especially in powerful jets to the west (retrograde). Unlike vortices, storms are short-lived phenomena; the strongest of them may be there for several months, while the average lifetime is only 3-4 days. They are believed to be primarily caused by wet convection within the Jupiter troposphere. The storm is actually a high convective column (lump), which carries wet air from depth to the top of the troposphere, where it condenses in clouds. The typical vertical storm level of Jovian is about 100 km; because they extend from a pressure level of about 5-7 bar, where the base of the hypothetical water cloud layer is located, as high as 0.2-0.5 bar.
Storms in Jupiter are always associated with lightning. The imagery of the night side of Jupiter by the Galileo and Cassini spacecraft revealed a regular light flash in the Jovian belt and near the location of the western jet, especially at 51 Â ° N, 56Ã, ° S and 14 Â ° S latitude. In the Jupiter illumination strike, it is on average several times stronger than the one on Earth. However, they are less frequent; the power of light emitted from a certain area similar to that of the Earth. Several flashes have been detected in the polar regions, making Jupiter the second planet known after Earth to show the polar lightning.
Every 15-17 years Jupiter is characterized by a very strong storm. They appear at latitudes 23 Â ° LU, where the strongest east jet, which can reach 150 m/s, is located. The last time such an event was observed was in March-June 2007. Two storms appeared in the northern temperate belt 55 Â ° parted with longitude. They significantly interfere with the belt. The dark matter shed by the storm mixes with the cloud and changes the color of the belt. Storms move at a speed of 170 m/s, slightly faster than the jet itself, signaling the presence of strong winds in the atmosphere.
Disorders
The pattern of bands and normal zones is sometimes disrupted over a period of time. One particular class of disturbance is the long-term embezzlement of the South Tropical Zone, commonly referred to as the "Southern Tropical Disorder" (STD). The longest STD that lives in recorded history followed from 1901 to 1939, having first been seen by Percy B. Molesworth on February 28, 1901. It took the form of embezzlement in parts of the normally sunny Tropical Zone. Several similar disorders in the South Tropical Zone have been recorded since then.
Hot spot
One of the most mysterious features in Jupiter's atmosphere is the hot spot. In it the air is relatively free of clouds and heat can get out of the depth without much absorption. The spots look like bright spots on the infrared image obtained at a wavelength of about 5 m. They are exclusively located on belts, although there is a prominent hot spot train at the northern end of the Equatorial Zone. Galileo Probe descends to one of those equatorial points. Each equatorial spot is associated with a bright cloud of clouds that lies to the west and reaches up to 10,000 km in size. Hot spots generally have a round shape, though they do not resemble a vortex.
The origin of hot spots is not clear. They can be downdrafts, in which adiabatically descending air is heated and dried or, alternatively, they can be manifestations of planetary-scale waves. The latter hypothesis describes the periodic pattern of equatorial points.
Observation history
Early modern astronomers, using a small telescope, noted the change in Jupiter's atmosphere. Their descriptive terms - belts and zones, brown spots and red spots, feathers, barges, ornaments, and ribbons - are still used. Other terms such as vortices, vertical motions, cloud heights have been in use later, in the 20th century.
The first observations of the Jovian atmosphere at a higher resolution of the possibilities with an Earth-based telescope were taken by the Pioneer 10 and 11 spacecraft. The first description of Jupiter's atmosphere is actually provided by Voyagers . Both spacecraft are capable of detailed images at resolutions as low as 5 km in various spectra, and are also capable of creating "film approach" of the moving atmosphere. The Galileo Probe, which is experiencing antenna problems, sees less of Jupiter's atmosphere but at better average resolution and wider spectral bandwidth.
Today, astronomers have access to a continuous record of Jupiter's atmospheric activity thanks to telescopes such as the Hubble Space Telescope. This suggests that the atmosphere is sometimes plagued by a major annoyance, but it is, on the whole, very stable. The vertical motion of Jupiter's atmosphere is largely determined by the identification of traces of gas by ground-based telescopes. Spectroscopic studies after the collision of Comet Shoemaker-Levy 9 gives a glimpse of Jupiter's composition below the cloud tops. The presence of diatomic sulfur (S 2 ) and carbon disulphide (CS 2 ) was recorded - the first detection was good in Jupiter, and only the second detection of S 2 in astronomical objects - along with other molecules such as ammonia (NH 3 ) and hydrogen sulfide (H 2 S), while oxygen-molecular bearings such as sulfur dioxide are undetectable, surprising astronomers.
The Galileo atmospheric probe, due to plunge into Jupiter, measures wind, temperature, composition, clouds, and radiation levels to 22 bars. However, under 1 bar elsewhere in Jupiter there is uncertainty in the quantity.
Great Red Spot Study
The first sighting of the GRS is often credited to Robert Hooke, who described the place on the planet in May 1664; However, it is likely that Hooke's place is in the wrong belt altogether (North Equatorial Belt, versus its current location in the Southern Equatorial Belt). Far more convincing is Giovanni Cassini's description of the "permanent place" of the following year. With fluctuations in visibility, where Cassini was observed from 1665 to 1713.
A small mystery concerns where Jovian is depicted sometime around 1700 on canvas by Donato Creti, which is on display at the Vatican. It is part of a series of panels in which different celestial bodies (enlarged) serve as a backdrop for various Italian scenes, the creation of all of them overseen by Eustachio Manfredi astronomer for accuracy. The Creti painting is the first known to describe the GRS as red. No Jovian feature was officially described as red before the end of the 19th century.
The GRS is currently first seen only after 1830 and was well studied only after a prominent appearance in 1879. The 118-year spacing separates observations made after 1830 from the 17th century invention; whether the original place is lost and re-formed, whether it fades, or even if the observation record is really poor is unknown. The older dots have short observation history and slower movements than modern places, which makes their identity impossible.
On February 25, 1979, when the spacecraft Voyager 1 was 9.2 million kilometers from Jupiter, it sent the first details of the Great Red Spot back to Earth. Cloud detail as small as 160 km visible. The colorful corrugated cloud patterns visible to the west (left) GRS are the wake-up areas, where incredible complex and variable cloud movements are observed.
White oval
The white Oval became BA Oval formed in 1939. They closed nearly 90 degrees longitude shortly after their formation, but contracted rapidly during their first decade; Their lengths were stable at 10 degrees or less after 1965. Although they originated as STZ segments, they evolved into fully embedded in the Southern Temper Belt, suggesting that they moved north, "digging" a niche into the STB. Indeed, very similar to the GRS, their circulation is limited by two opposite jet streams on their northern and southern border, with the east jet to their north and backward westward to the south.
The oval longitudinal movement appears to be influenced by two factors: Jupiter's position in its orbit (they become faster in aphelion), and its proximity to the GRS (they accelerate when within 50 degrees of the Spot). The overall trend of white oval drift rate is deceleration, with a decrease of half between 1940 and 1990.
Source of the article : Wikipedia
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