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August 1972 Solar Storms
The solar storms of August 1972 were a historically powerful series of solar storms with intense to extreme solar flare, solar particle event, and geomagnetic storm components in early August 1972, during solar cycle 20. The storm caused widespread electric- and communication-grid disturbances through large portions of North America as well as satellite disruptions. On 4 August 1972 the storm caused the accidental detonation of numerous U.S. naval mines near Haiphong, North Vietnam. The coronal mass ejection (CME)'s transit time from the Sun to the Earth is the fastest ever recorded. Solar-terrestrial characteristics Sunspot region The most significant detected solar flare activity occurred from 2 to 11 August. Most of the significant solar activity emanated from active sunspot region McMath 11976 (MR 11976; active regions being clusters of sunspot pairs). McMath 11976 was extraordinarily magnetically complex. Its size was large although not exceptionally so. McMath 11976 produ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Active Region
In solar physics and observation, an active region is a temporary feature in the Sun's atmosphere characterized by a strong and complex magnetic field. They are often associated with sunspots and are commonly the source of violent eruptions such as coronal mass ejections and solar flares. The number and location of active regions on the solar disk at any given time is dependent on the solar cycle. Region numbers Newly observed active regions on the solar disk are assigned 4-digit region numbers by the Space Weather Prediction Center (SWPC) on the day following the initial observation. The region number assigned to a particular active region is one added to the previously assigned number. For example, the first observation of active region 8090, or AR8090, was followed by AR8091. According to the SWPC, a number is assigned to a region if it meets at least one of the following criteria: # It contains a sunspot group of class C or larger based on the Modified Zurich Class sunsp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Solar Rotation
Solar rotation varies with latitude. The Sun is not a solid body, but is composed of a gaseous plasma. Different latitudes rotate at different periods. The source of this differential rotation is an area of current research in solar astronomy. The rate of surface rotation is observed to be the fastest at the equator (latitude ) and to decrease as latitude increases. The solar rotation period is 25.67 days at the equator and 33.40 days at 75 degrees of latitude. The Carrington a system for tracking the Sun's rotation, as seen from at the current UTC time of , is CR . Surface rotation as an equation The differential rotation rate of the photosphere can be approximated by the equation: :\omega=A+B\,\sin^2(\varphi)+C\,\sin^4(\varphi) where \omega is the angular velocity in degrees per day, \varphi is the solar latitude, A is angular velocity at the equator, and B, C are constants controlling the decrease in velocity with increasing latitude. The values of A, B, and C differ d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Solar Wind
The solar wind is a stream of charged particles released from the Sun's outermost atmospheric layer, the Stellar corona, corona. This Plasma (physics), plasma mostly consists of electrons, protons and alpha particles with kinetic energy between . The composition of the solar wind plasma also includes a mixture of particle species found in the solar plasma: trace amounts of heavy ions and atomic nuclei of Chemical element, elements such as carbon, nitrogen, oxygen, neon, magnesium, silicon, sulfur, and iron. There are also rarer traces of some other nuclei and isotopes such as phosphorus, titanium, chromium, and nickel's isotopes 58Ni, 60Ni, and 62Ni. Superimposed with the solar-wind plasma is the interplanetary magnetic field. The solar wind varies in density, temperature and speed over time and over Solar coordinate systems#Heliographic, solar latitude and longitude. Its particles can escape the Sun's gravity because of their high energy resulting from the high temperature of t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ejecta
Ejecta (; ) are particles ejected from an area. In volcanology, in particular, the term refers to particles including pyroclastic rock, pyroclastic materials (tephra) that came out of a explosive eruption, volcanic explosion and magma eruption volcano, volcanic vent, or volcanic crater, crater, has traveled through the air or water, and fell back to the ground surface or seabed, ocean floor. Volcanology Typically in volcanology, ejecta is a result of explosive eruptions. In an explosive eruption, large amounts of volcanic gas, gas are dissolved in extremely viscous lava; this lava froths to the surface until the material is expelled rapidly due to the trapped pressure. Sometimes in such an event a lava plug or volcanic neck forms from lava that solidifies inside a volcano's vent, causing heat and pressure to build up to an extreme with no way to escape. When the blockage breaks and cannot sustain itself any longer, a more violent eruption occurs, which allows materials to be e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Carrington Event
The Carrington Event was the most intense geomagnetic storm in recorded history, peaking on 1–2 September 1859 during solar cycle 10. It created strong auroral displays that were reported globally and caused sparking and even fires in telegraph stations. The geomagnetic storm was most likely the result of a coronal mass ejection (CME) from the Sun colliding with Earth's magnetosphere. The geomagnetic storm was associated with a very bright solar flare on 1 September 1859. It was observed and recorded independently by British astronomers Richard Carrington and Richard Hodgson—the first records of a solar flare. A geomagnetic storm of this magnitude occurring today has the potential to cause widespread electrical disruptions, blackouts, and damage to the electrical power grid. History Geomagnetic storm On 1 and 2 September 1859, one of the largest geomagnetic storms (as recorded by ground-based magnetometers) occurred. Estimates of the storm strength ( Dst) rang ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Outlier
In statistics, an outlier is a data point that differs significantly from other observations. An outlier may be due to a variability in the measurement, an indication of novel data, or it may be the result of experimental error; the latter are sometimes excluded from the data set. An outlier can be an indication of exciting possibility, but can also cause serious problems in statistical analyses. Outliers can occur by chance in any distribution, but they can indicate novel behaviour or structures in the data-set, measurement error, or that the population has a heavy-tailed distribution. In the case of measurement error, one wishes to discard them or use statistics that are robust statistics, robust to outliers, while in the case of heavy-tailed distributions, they indicate that the distribution has high skewness and that one should be very cautious in using tools or intuitions that assume a normal distribution. A frequent cause of outliers is a mixture of two distributions, wh ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Astronomical Unit
The astronomical unit (symbol: au or AU) is a unit of length defined to be exactly equal to . Historically, the astronomical unit was conceived as the average Earth-Sun distance (the average of Earth's aphelion and perihelion), before its modern redefinition in 2012. The astronomical unit is used primarily for measuring distances within the Solar System or around other stars. It is also a fundamental component in the definition of another unit of astronomical length, the parsec. One au is approximately equivalent to 499 light-seconds. History of symbol usage A variety of unit symbols and abbreviations have been in use for the astronomical unit. In a 1976 resolution, the International Astronomical Union (IAU) had used the symbol ''A'' to denote a length equal to the astronomical unit. In the astronomical literature, the symbol AU is common. In 2006, the International Bureau of Weights and Measures (BIPM) had recommended ua as the symbol for the unit, from the French ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
July 2012 Solar Storm
The solar storm of 2012 was a solar storm involving an unusually large and strong coronal mass ejection that occurred on July 23, 2012. It missed Earth by a margin of roughly nine days, as the Sun's equator solar rotation, rotates around its own axis once over a period of about 25 days. The region that produced the outburst was thus not pointed directly towards Earth at that time. The strength of the eruption has been predicted to be comparable to the 1859 Carrington Event that caused damage to electrical equipment worldwide, which at that time consisted mostly of electrical telegraph, telegraph systems. Overview At 02:08 Coordinated Universal Time, UT on 23 July 2012, a large coronal mass ejection (CME) was launched from the Sun. The eruption emanated from solar active region 11520 and coincided with what was at most an solar flare#Soft X-ray classification, X2.5-class solar flare. The CME expelled a pair of adjacent magnetic clouds that drove a fast-moving shock wa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
