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113-588: As of 2022 it is Argentina's southernmost permanent base, the world's third furthest south permanent base, and the world's southernmost base built on solid rock, which makes it particularly suited for geological research. As of 2022 Belgrano II is one of 13 research stations in Antarctica operated by Argentina. In 1955, then Brigade General Hernán Pujato founded the first Belgrano Base ( Belgrano I ), which remained for years as Argentina's southernmost settlement. After 25 years of continuous activity, Belgrano I

226-476: A maréchal de camp wore two stars. During the French Revolution , the revolutionaries' drive to rationalise the state led to a change in the system of ranks. The rank of brigadier des armées was abolished and the normal brigade command rank, maréchal de camp , was replaced by brigade general. The rank of brigade general inherited the two stars of the rank of maréchal de camp , explaining

339-555: A General de Brigada wears a two-star insignia. Hence, it is equivalent to the major general rank of many countries. In the Brazilian Air Force , all of the senior ranks include 'Brigadeiro'; the two-star rank is Brigadeiro (Brigadier), the three-star rank is Major-Brigadeiro (Major-Brigadier), and the four-star rank is Tenente-Brigadeiro-do-Ar (Lieutenant-Air-Brigadier). In the Canadian Forces ,

452-664: A Historic Site or Monument , following a proposal by Argentina to the Antarctic Treaty Consultative Meeting . Belgrano II is about 1,300 km (810 mi) from the South Pole and 2,500 km (1,600 mi) from Ushuaia, the nearest port city. As of 2014 it is Argentina's southernmost permanent base, and the third further south permanent base in the planet. It is also the world's southmost base built on solid rock, which gives it unique advantages for seismological and geological research. As

565-624: A colonel. Prior to 2001, the Bangladesh Army rank was known as brigadier , in conformity with the rank structure of the Commonwealth Nations . In 2001 the Bangladesh Army introduced the rank of brigadier general , however "the grade stayed equivalent to brigadier", and although classified as a "one-star rank", a brigadier general is not considered to be a general officer – the lowest ranking general officer

678-401: A geomagnetic storm temporarily enlarges the auroral oval. Large geomagnetic storms are most common during the peak of the 11-year sunspot cycle or during the three years after the peak. An electron spirals (gyrates) about a field line at an angle that is determined by its velocity vectors, parallel and perpendicular, respectively, to the local geomagnetic field vector B. This angle is known as

791-432: A particle depends on the particle's pitch angle : the angle between its direction of motion and the local magnetic field. An aurora is created by processes that decrease the pitch angle of many individual electrons, freeing them from the magnetic trap and causing them to hit the atmosphere. In the case of diffuse auroras, the electron pitch angles are altered by their interaction with various plasma waves . Each interaction

904-489: A result of its latitude, the summer day and winter night are four months long and the night sky often displays the aurora australis . As of 2014 Belgrano II is composed of a dozen buildings stationed on the nunatak rock, spanning a total area of 6 ha (60,000 m; 650,000 sq ft). Structures are mostly of composite panels covered by metal or fiberglass filled with polyurethane foam to provide adequate thermal insulation to resist low temperatures. Some of

1017-429: A satellite dish antenna for data transmission were also set up. On the morning of 10 September 2005 the main house was completely destroyed as a result of a fire caused by a heater malfunction. Personnel had to be distributed to other buildings and new food and clothes had to be brought from the mainland and airdropped as the fire had destroyed all the wintering elements. The construction of emergency facilities to solve

1130-409: A single silver maple leaf beneath crossed sabre and baton, all surmounted by St. Edward's Crown , worn on the shoulder straps of the service dress jacket, and on slip-ons on other uniforms. The rank insignia on army uniforms is a gold maple leaf beneath crossed sword and baton, all surmounted by St. Edward's Crown, on the shoulder straps. On the visor of the service cap are two rows of gold oak leaves;

1243-513: A southward component of the IMF, which can then directly connect to the high latitude geomagnetic field lines. The flow pattern of magnetospheric plasma is mainly from the magnetotail toward Earth, around Earth and back into the solar wind through the magnetopause on the day-side. In addition to moving perpendicular to Earth's magnetic field, some magnetospheric plasma travels down along Earth's magnetic field lines, gains additional energy and loses it to

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1356-501: A velocity typically around 400 km/s, a density of around 5 ions/cm and a magnetic field intensity of around 2–5 nT (for comparison, Earth's surface field is typically 30,000–50,000 nT). During magnetic storms , in particular, flows can be several times faster; the interplanetary magnetic field (IMF) may also be much stronger. Joan Feynman deduced in the 1970s that the long-term averages of solar wind speed correlated with geomagnetic activity. Her work resulted from data collected by

1469-606: A weak glow (often deep red) observed around the two polar cusps, the field lines separating the ones that close through Earth from those that are swept into the tail and close remotely. Early work on the imaging of the auroras was done in 1949 by the University of Saskatchewan using the SCR-270 radar. The altitudes where auroral emissions occur were revealed by Carl Størmer and his colleagues, who used cameras to triangulate more than 12,000 auroras. They discovered that most of

1582-535: A year. These factors combined can lead to minor cyclical changes in the detailed way that the IMF links to the magnetosphere. In turn, this affects the average probability of opening a door through which energy from the solar wind can reach Earth's inner magnetosphere and thereby enhance auroras. Recent evidence in 2021 has shown that individual separate substorms may in fact be correlated networked communities. Just as there are many types of aurora, there are many different mechanisms that accelerate auroral particles into

1695-537: Is Major General . Brigadier general is equivalent to commodore of the Bangladesh Navy and air commodore of the Bangladesh Air Force . It is still more popularly called brigadier . The Belgian Army uses the rank of général de brigade ( French ) and brigadegeneraal ( Dutch , 'brigade general'). However, in this small military there are no permanent promotions to this rank, and it

1808-409: Is a military rank used in many countries. The rank is usually above a colonel , and below a major general or divisional general . When appointed to a field command, a brigadier general is typically in command of a brigade consisting of around 4,000 troops (two regiments or four battalions ). Brigadier general ( Brig. Gen. ) is a military rank used in many countries. The rank originates from

1921-615: Is an infantry brigade. The two brigade group structure envisages distinct operational areas of responsibility for each of the brigades and is supported in its responsibilities by the Naval Service and Air Corps. Each of the brigade formations and the Air Corps is commanded by a brigadier general, while the Naval Service is commanded by a commodore. In the Italian Armed Forces the rank has different denominations. In

2034-916: Is associated with the lowest level within the government top management. Within the Mexican Armed Forces , there exists two grades of brigadier general. The lowest general officer is General brigadier , with the second lowest being General de brigada . The general officer rank higher than the two brigadier generals is Divisional general . In the Philippines, Brigadier General ( Philippine Army Philippine Air Force and Philippine Marines )/ Commodore ( Philippine Navy and Philippine Coast Guard )/ Chief Superintendent ( Bureau of Fire Protection and Bureau of Jail Management and Penology ) / Police Brigadier General (Chief Superintendent before) ( Philippine National Police ) / Gial De Brigada (1890–1902) ( Philippine Revolutionary Army )

2147-643: Is equivalent to the rank of rear admiral (lower half) in the other uniformed services . In the Uruguayan Air Force , a brigadier general is the second highest rank in its hierarchy, behind the air general, and the first of the general officers to be achieved. It is equivalent to the rank of general in the Army and counter admiral in the Navy . Each brigadier general is appointed by the Executive with

2260-443: Is essentially wave-particle scattering ; the electron energy after interacting with the wave is similar to its energy before interaction, but the direction of motion is altered. If the final direction of motion after scattering is close to the field line (specifically, if it falls within the loss cone ) then the electron will hit the atmosphere. Diffuse auroras are caused by the collective effect of many such scattered electrons hitting

2373-444: Is generally accompanied by decreasing peak emission heights of about 8 km for blue and green emissions and above average solar wind speeds ( c.  500   km/s ). In addition, the aurora and associated currents produce a strong radio emission around 150 kHz known as auroral kilometric radiation (AKR), discovered in 1972. Ionospheric absorption makes AKR only observable from space. X-ray emissions, originating from

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2486-520: Is induced within the conductor. The strength of the current depends on a) the rate of relative motion, b) the strength of the magnetic field, c) the number of conductors ganged together and d) the distance between the conductor and the magnetic field, while the direction of flow is dependent upon the direction of relative motion. Dynamos make use of this basic process ("the dynamo effect "), any and all conductors, solid or otherwise are so affected, including plasmas and other fluids. The IMF originates on

2599-477: Is located on a glacier 2 km (1.2 mi) southwest of the base. The one-bed infirmary is 21 m (230 sq ft), attended by a doctor and a nurse. It has x-ray and odontological facilities. Dug in the nearby ice, Belgrano II's Catholic Chapel of Our Lady of the Snows is the world's southernmost Christian church—in fact, it's the southernmost worship place of any religion. The general tasks of

2712-679: Is located on what was once the former home destroyed by fire. During the repairs of the Argentine Navy icebreaker ARA Almirante Irízar which is normally used to supply the base, the Argentine Air Force took over the task with airdrops by KC-130 Hercules aircraft in a non-stop flight from Ushuaia in Tierra del Fuego . A cross was erected in 1955 some 1,300 m (4,300 ft) north-east of Belgrano I and subsequently moved to Belgrano II in 1979. This has been designated

2825-484: Is more effectively transferred by the temporary magnetic connection between the field lines of the solar wind and those of the magnetosphere. Unsurprisingly this process is known as magnetic reconnection . As already mentioned, it happens most readily when the interplanetary field is directed southward, in a similar direction to the geomagnetic field in the inner regions of both the north magnetic pole and south magnetic pole . Auroras are more frequent and brighter during

2938-466: Is only awarded as a temporary promotion to a full colonel who assumes a post requiring the rank, notably in an international context (e.g. as military attaché in a major embassy). General de brigada (Brigade general) is the lowest rank amongst general officers of the Brazilian Army ; i.e. like in most British Commonwealth countries, the lowest general officer rank is a two-star rank , and

3051-427: Is operated by the civilian agency Argentine Antarctic Institute . As of 2010, the base has a 19 men crew two of whom are Air Force meteorologists, three are Argentine National Antarctic Directorate civilian researchers and the rest is Argentine Army personnel in charge of operating the base. The Belgrano II base has a coastal-influenced ice cap climate . The area is a passage of weather fronts directed towards

3164-407: Is regularly derived from ground data and serves as a general measure of auroral activity. Kristian Birkeland deduced that the currents flowed in the east–west directions along the auroral arc, and such currents, flowing from the dayside toward (approximately) midnight were later named "auroral electrojets" (see also Birkeland currents ). Ionosphere can contribute to the formation of auroral arcs via

3277-400: Is still used notwithstanding that brigades in the army are now commanded by colonels. Until the late 1990s brigades were commanded by brigadier-generals. In the air force context, brigadier-generals used to command air force groups until these bodies were abolished in the late 1990s. The rank insignia for a brigadier-general on air force uniforms is a single wide braid on the cuff, as well as

3390-547: Is the immediately superior two-star rank . While the Chilean Air Force uses Comodoro for its one-star rank, two-star Air Force officers hold the rank of General de Brigada Aérea  – literally 'air brigade general'. The rank of brigadier general was established in 1953 by decree 1325 on the 21st of May. With this decree, the ranks of lieutenant general and general were replaced by brigadier general and lieutenant general establishing brigadier as

3503-526: Is the lowest general officer before Divisional General ( Spanish : General de Division ) and Lieutenant General ( Spanish : Teniente General ). In the Australian Imperial Force during World War I , the rank of brigadier general was always temporary and held only while the officer was posted to a particular task, typically the command of a brigade. (Until 1915, Australian brigades were commanded by colonels.) When posted elsewhere,

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3616-687: Is the lowest rank of generals but already eligible in the promotion to become Chief of Staff of the Armed Forces of the Philippines or PNP Chief of the Philippine National Police surpassing the Major General and Lieutenant General ranks. Generał brygady (literally, "general of a brigade", abbreviated gen. bryg. ) is the lowest-ranking general in the Polish Land Forces and Air Force . In

3729-565: Is titled "general" without any implication that he is an army general ; for instance General Charles de Gaulle never rose higher than brigade general. Until 1793, the rank of brigadier des armées ("brigadier of the armies") existed in the French Army , which could be described as a senior colonel or junior brigade commander. The normal brigade command rank was maréchal de camp (literally "camp marshal"). When rank insignia were introduced, brigadier des armées wore one star and

3842-560: Is used for the designated rank of the general officers that the country stipulates as brigade commanders' class by law. The rank of brigadier general (with some local variations) is used in the Argentine Air Force . Unlike other armed forces of the World, the rank of brigadier general is actually the highest rank in the Air Force. This is due to the use of the rank of brigadier and its derivatives to designate all general officers in

3955-522: Is why there is a color differential with altitude; at high altitudes oxygen red dominates, then oxygen green and nitrogen blue/purple/red, then finally nitrogen blue/purple/red when collisions prevent oxygen from emitting anything. Green is the most common colour. Then comes pink, a mixture of light green and red, followed by pure red, then yellow (a mixture of red and green), and finally, pure blue. Precipitating protons generally produce optical emissions as incident hydrogen atoms after gaining electrons from

4068-462: Is −7.7 °C (18.1 °F). In winter, the average high and low are −15.9 °C (3.4 °F) and −23.6 °C (−10.5 °F) respectively. During the polar night, a lot of aurorae can be observed. Snowfall occurs throughout the year; on average, there are 143 days with snow. January to April are the snowiest periods of the year with each month receiving 13 to 14 days with snow. Brigade General Brigadier general or brigade general

4181-511: The 4th Armoured Division ( 4 division cuirassée ). However his initial authority as head of the Free French really came from being the only cabinet member (Under-Secretary of State for National Defence and War ) outside occupied France , not from his military rank. As a reminder of his war position, he refused any further promotion. The country is divided into two areas for administrative and operational reasons, and in each area there

4294-524: The Arctic and Antarctic ). Auroras display dynamic patterns of brilliant lights that appear as curtains, rays, spirals, or dynamic flickers covering the entire sky. Auroras are the result of disturbances in the Earth's magnetosphere caused by the solar wind . Major disturbances result from enhancements in the speed of the solar wind from coronal holes and coronal mass ejections . These disturbances alter

4407-436: The Army , the rank for combat arms officers is generale di brigata whilst for the logistics and technical corps is called brigadier generale . In 1926, the brigadiere generale and maggior generale in comando di brigata were merged and renamed with their current rank designation.The rank is also present in the other armed forces, police corps and other services of Italy , with different denominations, and it

4520-481: The Explorer 33 spacecraft. The solar wind and magnetosphere consist of plasma (ionized gas), which conducts electricity. It is well known (since Michael Faraday 's work around 1830) that when an electrical conductor is placed within a magnetic field while relative motion occurs in a direction that the conductor cuts across (or is cut by ), rather than along , the lines of the magnetic field, an electric current

4633-496: The Old European System . It is the lowest ranking general officer in some countries, usually sitting between the ranks of colonel and major general . When appointed to a field command, a brigadier general is typically in command of a brigade consisting of around 4,000 troops (four battalions ). In some countries, this rank is given the name of brigadier , which is usually equivalent to brigadier general in

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4746-550: The Portuguese Army and Air Force , brigadeiro-general is a temporary general rank for the colonels that have to exercise a special command. It is the equivalent of the commodore rank in the Portuguese Navy . The rank was reintroduced in 1999. Before that, simply as brigadeiro , it existed from 1707 to 1864 and again from 1929 to 1947, not being considered a general rank. From 1947 to 1999, brigadeiro become

4859-689: The Royal Canadian Air Force , Canadian Army , and the Royal Canadian Navy , rank structure and insignia followed the British pattern. This system of rank insignia was reinstated in 2014. In army usage, the term "brigadier" was used to denote what is now known as a brigadier-general while the air force used the rank of air commodore . In the Chilean Army , Brigadier is a one-star rank and General de Brigada

4972-609: The Sargento Ayudante Cisterna y el Aviso ARA Comandante Zapiola shelters had been set up in January 1976. In addition to new instruments brought from the mainland, Belgrano II received all the scientific equipment transferred from Belgrano I. The LABEL laboratory (LAboratory BELgrano) was rebuilt demanding considerable effort. A new facility, the José Luis Sersic polar astronomical observatory and

5085-648: The Turkish Air Force , the equivalent rank is tuğgeneral (the Turkish Navy equivalent is tuğamiral ). The name is derived from tugay , the Turkish word for a brigade. Both tugay and tuğ - as military terms may owe their origins to the older Turkish word tuğ , meaning horsetail, which was used as a symbol of authority and rank in Ottoman and pre-Ottoman times. Brigadier-general

5198-467: The feedback instability under high ionospheric resistance conditions, observed at night time and in dark Winter hemisphere. Earth is constantly immersed in the solar wind , a flow of magnetized hot plasma (a gas of free electrons and positive ions) emitted by the Sun in all directions, a result of the two-million-degree temperature of the Sun's outermost layer, the corona . The solar wind reaches Earth with

5311-522: The icebreaker ARA General San Martín . The new housing facilities were a vast improvement over the previous base ones: since 1955, the men who wintered in the old Belgrano I Base were living inside tunnels dug in the ice, ice that was always moving slowly towards the sea and, as finally happened, would become a tabular iceberg drifting through the Southern Ocean . In its area of influence two Argentine-built refuges existed since long before:

5424-411: The mesosphere in presence of electron precipitation . Horse-collar auroras (HCA) are auroral features in which the auroral ellipse shifts poleward during the dawn and dusk portions and the polar cap becomes teardrop-shaped. They form during periods when the interplanetary magnetic field (IMF) is permanently northward, when the IMF clock angle is small. Their formation is associated with the closure of

5537-455: The "pitch angle" of the particle. The distance, or radius, of the electron from the field line at any time is known as its Larmor radius. The pitch angle increases as the electron travels to a region of greater field strength nearer to the atmosphere. Thus, it is possible for some particles to return, or mirror, if the angle becomes 90° before entering the atmosphere to collide with the denser molecules there. Other particles that do not mirror enter

5650-409: The 1960s by many research teams using rockets and satellites to traverse the auroral zone. The main findings have been that auroral arcs and other bright forms are due to electrons that have been accelerated during the final few 10,000 km or so of their plunge into the atmosphere. These electrons often, but not always, exhibit a peak in their energy distribution, and are preferentially aligned along

5763-683: The Air Force: brigadier (lowest general officer); brigadier-major (middle); and brigadier-general (highest). The rank of brigadier general is reserved for the Chief General Staff of the Air Force, as well as the Chief of the Joint General Staff if he should be an Air Force officer. The Argentine Army does not use the rank of brigadier-general, instead using brigade general ( Spanish : General de brigada ) which in turn

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5876-515: The Roman goddess of the dawn, Aurora , who travelled from east to west announcing the coming of the Sun . Ancient Greek poets used the corresponding name " Eos " metaphorically to refer to dawn, often mentioning its play of colours across the otherwise dark sky (e.g., "rosy-fingered dawn"). The words borealis and australis are derived from the names of the ancient gods of the north wind ( Boreas ) and

5989-524: The Sun, linked to the sunspots , and its field lines (lines of force) are dragged out by the solar wind. That alone would tend to line them up in the Sun-Earth direction, but the rotation of the Sun angles them at Earth by about 45 degrees forming a spiral in the ecliptic plane, known as the Parker spiral . The field lines passing Earth are therefore usually linked to those near the western edge ("limb") of

6102-499: The absence since 1793 of a French rank with only one star. For this reason, in France, the rank corresponding to brigade general was changed to brigadier general after NATO was established on April 4, 1949, and before that, it corresponded to major general. Nowadays, a French général de brigade generally commands a brigade. The rank can also be awarded in an honorary fashion to retiring colonels. The insignia are two stars, worn on

6215-674: The air force wedge cap features silver braid on the edges of the ear flaps. The cap insignia for a general officer is a modified version of the Canadian Forces insignia. Army brigadier-generals wear gorget patches on the collar of the service uniform tunic. Brigadier-generals are initially addressed verbally as "General" and name; thereafter by subordinates as "Sir" or "Ma'am" in English or mon général in French. They are normally entitled to staff cars . Until unification in 1968 of

6328-588: The amount of acceleration imparted to the precipitating particles. Most of the planets in the Solar System , some natural satellites , brown dwarfs , and even comets also host auroras. The term aurora borealis was coined by Galileo in 1619, from the Roman Aurora, goddess of the dawn , and the Greek Boreas, god of the cold north wind . The word aurora is derived from the name of

6441-625: The approval of the Senate , in accordance with Article 168 of the Constitution of the Republic . Bibliography Aurora (astronomy) An aurora ( pl. aurorae or auroras ), also commonly known as the northern lights ( aurora borealis ) or southern lights ( aurora australis ), is a natural light display in Earth 's sky, predominantly seen in high-latitude regions (around

6554-414: The armies of nations that use the rank. The rank can be traced back to the militaries of Europe where a "brigadier general", or simply a "brigadier", would command a brigade in the field. In the first quarter of the 20th century, British and Commonwealth armies used the rank of brigadier general as a temporary appointment, or as an honorary appointment on retirement; in the 1920s this practice changed to

6667-486: The atmosphere and contribute to the auroral display over a range of altitudes. Other types of auroras have been observed from space; for example, "poleward arcs" stretching sunward across the polar cap, the related "theta aurora", and "dayside arcs" near noon. These are relatively infrequent and poorly understood. Other interesting effects occur such as pulsating aurora, "black aurora" and their rarer companion "anti-black aurora" and subvisual red arcs. In addition to all these,

6780-423: The atmosphere in the auroral zones. The cusps of the magnetosphere, separating geomagnetic field lines that close through Earth from those that close remotely allow a small amount of solar wind to directly reach the top of the atmosphere, producing an auroral glow. On 26 February 2008, THEMIS probes were able to determine, for the first time, the triggering event for the onset of magnetospheric substorms . Two of

6893-456: The atmosphere. Electron aurora in Earth's auroral zone (i.e. commonly visible aurora) can be split into two main categories with different immediate causes: diffuse and discrete aurora. Diffuse aurora appear relatively structureless to an observer on the ground, with indistinct edges and amorphous forms. Discrete aurora are structured into distinct features with well-defined edges such as arcs, rays and coronas; they also tend to be much brighter than

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7006-447: The atmosphere. Proton auroras are usually observed at lower latitudes. Bright auroras are generally associated with Birkeland currents (Schield et al., 1969; Zmuda and Armstrong, 1973 ), which flow down into the ionosphere on one side of the pole and out on the other. In between, some of the current connects directly through the ionospheric E layer (125 km); the rest ("region 2") detours, leaving again through field lines closer to

7119-439: The atmosphere. The process is mediated by the plasma waves, which become stronger during periods of high geomagnetic activity , leading to increased diffuse aurora at those times. In the case of discrete auroras, the trapped electrons are accelerated toward Earth by electric fields that form at an altitude of about 4000–12000 km in the "auroral acceleration region". The electric fields point away from Earth (i.e. upward) along

7232-732: The aurora borealis and changes simultaneously with changes in the northern auroral zone. The aurora australis is visible from high southern latitudes in Antarctica , the Southern Cone , South Africa , Australasia and under exceptional circumstances as far north as Uruguay . The aurora borealis is visible from areas around the Arctic such as Alaska , Canada , Iceland , Greenland , the Faroe Islands , Scandinavia , Finland , Scotland , and Russia . A geomagnetic storm causes

7345-518: The auroral oval to active displays along the darkside and after 1–3 hours they gradually change back. Changes in auroras over time are commonly visualized using keograms . At shorter time scales, auroras can change their appearances and intensity, sometimes so slowly as to be difficult to notice, and at other times rapidly down to the sub-second scale. The phenomenon of pulsating auroras is an example of intensity variations over short timescales, typically with periods of 2–20 seconds. This type of aurora

7458-726: The auroral ovals (north and south) to expand, bringing the aurora to lower latitudes. On rare occasions, the aurora borealis can be seen as far south as the Mediterranean and the southern states of the US while the aurora australis can be seen as far north as New Caledonia and the Pilbara region in Western Australia . During the Carrington Event , the greatest geomagnetic storm ever observed, auroras were seen even in

7571-412: The background magnetic field (comparable to the electron inertial length or ion gyroradius ), Alfvén waves develop a significant electric field parallel to the background magnetic field. This electric field can accelerate electrons to keV energies, significant to produce auroral arcs. If the electrons have a speed close to that of the wave's phase velocity, they are accelerated in a manner analogous to

7684-541: The base personnel are primarily of scientific research, survey and exploration, also providing support for foreign scientific efforts. Other common duties are shelter maintenance, search and rescue, medical, communications and weather forecast support to expeditions, bases, ships and aircraft, both local and foreign. The following research programs are run at LABEL: Although maintained by the Argentine Armed Forces , as all Argentine bases on Antarctica, it

7797-477: The centre), cap badge (crossed sword and baton within a laurel wreath, surmounted by a crown in gold embroidery) and cap visor (two rows of gold oakleaf embroidery) as other generals. As in the United Kingdom, the rank was later replaced by colonel commandant in 1922 and brigadier in 1928. However, those holding the rank of brigadier general continued to do so throughout the inter-war period, until

7910-465: The collision of particles precipitated into the atmosphere. Both incoming electrons and protons may be involved. Excitation energy is lost within the atmosphere by the emission of a photon, or by collision with another atom or molecule: Oxygen is unusual in terms of its return to ground state: it can take 0.7 seconds to emit the 557.7 nm green light and up to two minutes for the red 630.0 nm emission. Collisions with other atoms or molecules absorb

8023-468: The currents are the direct result of electron acceleration into the atmosphere by wave/particle interactions. Ionospheric resistance has a complex nature, and leads to a secondary Hall current flow. By a strange twist of physics, the magnetic disturbance on the ground due to the main current almost cancels out, so most of the observed effect of auroras is due to a secondary current, the auroral electrojet . An auroral electrojet index (measured in nanotesla)

8136-416: The diffuse aurora. In both cases, the electrons that eventually cause the aurora start out as electrons trapped by the magnetic field in Earth's magnetosphere . These trapped particles bounce back and forth along magnetic field lines and are prevented from hitting the atmosphere by the magnetic mirror formed by the increasing magnetic field strength closer to Earth. The magnetic mirror's ability to trap

8249-404: The dune aurora phenomenon was discovered by Finnish citizen scientists . It consists of regularly-spaced, parallel stripes of brighter emission in the green diffuse aurora which give the impression of sand dunes. The phenomenon is believed to be caused by the modulation of atomic oxygen density by a large-scale atmospheric wave travelling horizontally in a waveguide through an inversion layer in

8362-458: The electric field increases the kinetic energy of all of the electrons transiting downward through the acceleration region by the same amount. This accelerates electrons starting from the magnetosphere with initially low energies (tens of eV or less) to energies required to create an aurora (100s of eV or greater), allowing that large source of particles to contribute to creating auroral light. The accelerated electrons carry an electric current along

8475-454: The equator and closing through the "partial ring current" carried by magnetically trapped plasma. The ionosphere is an ohmic conductor , so some consider that such currents require a driving voltage, which an, as yet unspecified, dynamo mechanism can supply. Electric field probes in orbit above the polar cap suggest voltages of the order of 40,000 volts, rising up to more than 200,000 volts during intense magnetic storms. In another interpretation,

8588-490: The excitation energy and prevent emission; this process is called collisional quenching . Because the highest parts of the atmosphere contain a higher percentage of oxygen and lower particle densities, such collisions are rare enough to allow time for oxygen to emit red light. Collisions become more frequent progressing down into the atmosphere due to increasing density, so that red emissions do not have time to happen, and eventually, even green light emissions are prevented. This

8701-443: The facilities at the base are: main and personnel houses; emergency house/infirmary; airstrip; heliport; chapel; museum; radio station; meteorological station; power plant; vehicle fleet (several Tucker Sno-Cats and Yamaha VK-541 ski-doos ); atmospheric research station; mechanical, carpentry and electricity workshop; general equipment and spare parts warehouses; and foodstuff deposits (also called GUM). The all-year capable airstrip

8814-541: The first grade for generals. In the 60s these ranks were reformed once again creating a third rank, brigadier general, Major general, and general in the Fuerzas Militares , and the National Police . France uses the rank of "brigade general" ( général de brigade ). The rank contrasts with the French sub-officer rank of brigadier . As with all French general officers, a French brigade general

8927-465: The five probes, positioned approximately one third the distance to the Moon, measured events suggesting a magnetic reconnection event 96 seconds prior to auroral intensification. Geomagnetic storms that ignite auroras may occur more often during the months around the equinoxes . It is not well understood, but geomagnetic storms may vary with Earth's seasons. Two factors to consider are the tilt of both

9040-488: The housing problem started in early 2006, This new building was planned in two stages with the first one (bathrooms, kitchen and bedrooms) being finished in 2006–07 and the second one (living room), in 2007–08. During the 2008–09 campaign the construction of a new main house began. It was completed during the 2009–10 campaign and was inaugurated on 25 May 2010. The new house has a covered area of about 500 m (5,400 sq ft) with more comfort and space for recreation: it

9153-430: The intense phase of the solar cycle when coronal mass ejections increase the intensity of the solar wind. Earth's magnetosphere is shaped by the impact of the solar wind on Earth's magnetic field. This forms an obstacle to the flow, diverting it, at an average distance of about 70,000 km (11 Earth radii or Re), producing a bow shock 12,000 km to 15,000 km (1.9 to 2.4 Re) further upstream. The width of

9266-401: The interaction of the solar wind with Earth's magnetosphere . The varying intensity of the solar wind produces effects of different magnitudes but includes one or more of the following physical scenarios. The details of these phenomena are not fully understood. However, it is clear that the prime source of auroral particles is the solar wind feeding the magnetosphere, the reservoir containing

9379-567: The last of them retired or was promoted during the Second World War. A brigadier general was a general officer, but brigadiers were not generals, which is shown by the rank insignia being like that of a colonel, but with an extra (third) star/pip, and a brigadier wore the same gorget patches (scarlet cloth with a line of crimson gimp), cap badge (the Royal Crest in gold embroidery), and cap visor (one row of gold oakleaf embroidery) as

9492-509: The light is produced between 90 and 150 km (56 and 93 mi) above the ground, while extending at times to more than 1,000 km (620 mi). According to Clark (2007), there are five main forms that can be seen from the ground, from least to most visible: Brekke (1994) also described some auroras as "curtains". The similarity to curtains is often enhanced by folds within the arcs. Arcs can fragment or break up into separate, at times rapidly changing, often rayed features that may fill

9605-762: The local direction of the magnetic field. Electrons mainly responsible for diffuse and pulsating auroras have, in contrast, a smoothly falling energy distribution, and an angular (pitch-angle) distribution favouring directions perpendicular to the local magnetic field. Pulsations were discovered to originate at or close to the equatorial crossing point of auroral zone magnetic field lines. Protons are also associated with auroras, both discrete and diffuse. Auroras result from emissions of photons in Earth's upper atmosphere , above 80 km (50 mi), from ionized nitrogen atoms regaining an electron, and oxygen atoms and nitrogen based molecules returning from an excited state to ground state . They are ionized or excited by

9718-426: The magnetic field line. Electrons moving downward through these fields gain a substantial amount of energy (on the order of a few keV ) in the direction along the magnetic field line toward Earth. This field-aligned acceleration decreases the pitch angle for all of the electrons passing through the region, causing many of them to hit the upper atmosphere. In contrast to the scattering process leading to diffuse auroras,

9831-432: The magnetic field lines (a Birkeland current ). Since the electric field points in the same direction as the current, there is a net conversion of electromagnetic energy into particle energy in the auroral acceleration region (an electric load ). The energy to power this load is eventually supplied by the magnetized solar wind flowing around the obstacle of Earth's magnetic field, although exactly how that power flows through

9944-422: The magnetic flux at the top of the dayside magnetosphere by the double lobe reconnection (DLR). There are approximately 8 HCA events per month, with no seasonal dependence, and that the IMF must be within 30 degrees of northwards. Conjugate auroras are nearly exact mirror-image auroras found at conjugate points in the northern and southern hemispheres on the same geomagnetic field lines. These generally happen at

10057-413: The magnetosphere abreast of Earth is typically 190,000 km (30 Re), and on the night side a long "magnetotail" of stretched field lines extends to great distances (> 200 Re). The high latitude magnetosphere is filled with plasma as the solar wind passes Earth. The flow of plasma into the magnetosphere increases with additional turbulence, density, and speed in the solar wind. This flow is favoured by

10170-490: The magnetosphere is still an active area of research. While the energy to power the aurora is ultimately derived from the solar wind, the electrons themselves do not travel directly from the solar wind into Earth's auroral zone; magnetic field lines from these regions do not connect to the solar wind, so there is no direct access for solar wind electrons. Some auroral features are also created by electrons accelerated by dispersive Alfvén waves . At small wavelengths transverse to

10283-433: The noon direction and 23° away in the midnight direction. The peak equatorward extent of the oval is displaced slightly from geographic midnight. It is centered about 3–5° nightward of the magnetic pole, so that auroral arcs reach furthest toward the equator when the magnetic pole in question is in between the observer and the Sun , which is called magnetic midnight . Early evidence for a geomagnetic connection comes from

10396-450: The north: although they do not precipitate, they do produce strong winds exceeding 200 km/h (120 mph) which radically increase the chill factor . Mean monthly temperatures range from −20.4 °C (−4.7 °F) in July, the coldest month to −2.4 °C (27.7 °F) in January, the warmest month. During summer, the average high is −1.2 °C (29.8 °F) while the average low

10509-510: The opposite order. Until about 1963, it was thought that these changes are due to the rotation of the Earth under a pattern fixed with respect to the Sun. Later, it was found by comparing all-sky films of auroras from different places (collected during the International Geophysical Year ) that they often undergo global changes in a process called auroral substorm . They change in a few minutes from quiet arcs all along

10622-456: The particles associated with auroras, have also been detected. Aurora noise , similar to a crackling noise, begins about 70 m (230 ft) above Earth's surface and is caused by charged particles in an inversion layer of the atmosphere formed during a cold night. The charged particles discharge when particles from the Sun hit the inversion layer, creating the noise. In 2016, more than fifty citizen science observations described what

10735-593: The radiation zones and temporarily magnetically trapped particles confined by the geomagnetic field, coupled with particle acceleration processes. The immediate cause of the ionization and excitation of atmospheric constituents leading to auroral emissions was discovered in 1960, when a pioneering rocket flight from Fort Churchill in Canada revealed a flux of electrons entering the atmosphere from above. Since then an extensive collection of measurements has been acquired painstakingly and with steadily improving resolution since

10848-456: The rank of brigadier-general (BGen) ( brigadier-général or bgén in French) is a rank for members who wear army or air force uniform, equal to a commodore for those in navy uniform. A brigadier-general is the lowest rank of general officer . A brigadier-general is senior to a colonel or naval captain , and junior to a major-general or rear-admiral . The rank title brigadier-general

10961-452: The rank would be relinquished and the former rank resumed. This policy prevented an accumulation of high-ranking general officers brought about by the relatively high turnover of brigade commanders. Brigadier general was also used as an honorary rank on retirement. The rank insignia was like that of the current major general , but without the star/pip. Brigadier generals wore the same gorget patches (a line of gold oak leaf embroidery down

11074-509: The region, only two small masses of granite emerge: the Moltke and Bertrab nunataks , both first sighted and named by Filchner's expedition in 1912. Belgrano II was founded on 5 February 1979 over the latter, a hectare of permanently ice-free land. Also and despite being farther south and higher than Belgrano I, the climate was significantly milder. The unloading of the materials—equipment, tools and instruments, food and fuel—was conducted from

11187-431: The ribbon). The processes that cause STEVE are also associated with a picket-fence aurora, although the latter can be seen without STEVE. It is an aurora because it is caused by precipitation of electrons in the atmosphere but it appears outside the auroral oval, closer to the equator than typical auroras. When the picket-fence aurora appears with STEVE, it is below. First reported in 2020, and confirmed in 2021,

11300-451: The shoulder or at the sleeve of the uniform, depending on the order of dress. Two different kepis are issued: the service kepi sports the two stars, while the formal kepi features a large band of oak leaves (the kepi of a division general has two smaller such bands). Charles de Gaulle held the rank of brigade general. He was given a temporary promotion to this rank in May 1940 as commander of

11413-416: The solar and Earth's axis to the ecliptic plane. As Earth orbits throughout a year, it experiences an interplanetary magnetic field (IMF) from different latitudes of the Sun, which is tilted at 8 degrees. Similarly, the 23-degree tilt of Earth's axis about which the geomagnetic pole rotates with a diurnal variation changes the daily average angle that the geomagnetic field presents to the incident IMF throughout

11526-460: The south wind ( Auster ) in Greco-Roman mythology . Auroras are most commonly observed in the "auroral zone", a band approximately 6° (~660 km) wide in latitude centered on 67° north and south. The region that currently displays an aurora is called the "auroral oval". The oval is displaced by the solar wind, pushing it about 15° away from the geomagnetic pole (not the geographic pole) in

11639-402: The statistics of auroral observations. Elias Loomis (1860), and later Hermann Fritz (1881) and Sophus Tromholt (1881) in more detail, established that the aurora appeared mainly in the auroral zone. In northern latitudes , the effect is known as the aurora borealis or the northern lights. The southern counterpart, the aurora australis or the southern lights, has features almost identical to

11752-409: The time of the equinoxes , when there is little difference in the orientation of the north and south geomagnetic poles to the sun. Attempts were made to image conjugate auroras by aircraft from Alaska and New Zealand in 1967, 1968, 1970, and 1971, with some success. A full understanding of the physical processes which lead to different types of auroras is still incomplete, but the basic cause involves

11865-402: The trajectories of charged particles in the magnetospheric plasma . These particles, mainly electrons and protons , precipitate into the upper atmosphere ( thermosphere / exosphere ). The resulting ionization and excitation of atmospheric constituents emit light of varying colour and complexity. The form of the aurora, occurring within bands around both polar regions, is also dependent on

11978-414: The tropics. Auroras seen within the auroral oval may be directly overhead. From farther away, they illuminate the poleward horizon as a greenish glow, or sometimes a faint red, as if the Sun were rising from an unusual direction. Auroras also occur poleward of the auroral zone as either diffuse patches or arcs, which can be subvisual. Auroras are occasionally seen in latitudes below the auroral zone, when

12091-703: The two-star general rank in the Portuguese Army. As two-star rank, it was substituted by the rank of major-general in 1999. In the Spanish Army , Spanish Air Force , and Spanish Marine Infantry ( Infantería de Marina , a branch of the Armada ) general de brigada is the lowest rank of general officers. Its equivalent in the Navy ( Armada ) is contraalmirante . In the Turkish Army and

12204-492: The use of brigadier, which was not classed as a general officer. Brigade general is the rank of a brigade commander in countries where the French Revolutionary System's general officer rank designation is used. The rank name général de brigade ( transl.  brigade general ) was first used in the French revolutionary armies. It used both brigadier general and major general because it

12317-406: The visible Sun at any time. The solar wind and the magnetosphere, being two electrically conducting fluids in relative motion, should be able in principle to generate electric currents by dynamo action and impart energy from the flow of the solar wind. However, this process is hampered by the fact that plasmas conduct readily along magnetic field lines, but less readily perpendicular to them. Energy

12430-506: The whole sky. These are also known as discrete auroras , which are at times bright enough to read a newspaper by at night. These forms are consistent with auroras being shaped by Earth's magnetic field. The appearances of arcs, rays, curtains, and coronas are determined by the shapes of the luminous parts of the atmosphere and a viewer's position . Auroras change with time. Over the night they begin with glows and progress toward coronas, although they may not reach them. They tend to fade in

12543-490: Was closed due to the fast deterioration of the ice barrier it was sitting on; new, often hidden cracks and crevices endangered the on-duty personnel and material. In order to continue the scientific programs and keep Argentina presence in the area, and after careful studies on alternative locations done by the Argentine Army , it was decided to lay the new facilities on solid land. Amid the vast expanse of ice that covers

12656-701: Was formerly a rank or appointment in the British Army and Royal Marines , and briefly in the Royal Air Force . The appointment was abolished in the Army and the Marines in 1921; the equivalent rank today is Brigadier . In the United States Army , United States Air Force , United States Marine Corps , and United States Space Force , a brigadier general is a one-star general officer . It

12769-424: Was to them an unknown type of aurora which they named " STEVE ", for "Strong Thermal Emission Velocity Enhancement". STEVE is not an aurora but is caused by a 25 km (16 mi) wide ribbon of hot plasma at an altitude of 450 km (280 mi), with a temperature of 3,000 °C (3,270 K; 5,430 °F) and flowing at a speed of 6 km/s (3.7 mi/s) (compared to 10 m/s (33 ft/s) outside

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