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List Of Solar Storms
Solar storms of different types are caused by disturbances on the Sun, most often from coronal mass ejections (CMEs) and solar flares from active regions, or, less often, from coronal holes. Minor to active solar storms (i.e. storming restricted to higher latitudes) may occur under elevated background solar wind conditions when the interplanetary magnetic field (IMF) orientation is southward, toward the Earth (which also leads to much stronger storming conditions from CME-related sources). Background Active stars produce disturbances in space weather and, if strong enough, in their own space climate. Science studies such phenomena with the field of heliophysics, which is an interdisciplinary combination of solar physics and planetary science. In the Solar System, the Sun can produce intense Geomagnetic storm, geomagnetic and Solar particle event, energetic particle storms capable of causing severe damage to technology. It can result in large scale power outages, disruption or Com ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Coronal Cloud 1
Coronal may refer to: * a nuptial crown * anything relating to a corona * Coronal plane, an anatomical term of location * The coronal direction on a tooth * Coronal consonant, a consonant that is articulated with the front part of the tongue * Coronal stop A coronal stop is a stop consonant articulated with the front part of the tongue (whence " coronal"). Depending on the precise place of articulation, several types can be distinguished: * Dental stops, articulated with the tongue touching the upper ..., a type of stop consonant * Coronal loop, a structure on the surface of the Sun {{disambig ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Communications Blackout
In telecommunications, communications blackouts are * a cessation of communications or communications capability, caused by a lack of power to a communications facility or to communications equipment. * a total lack of radio communications capability, caused by ionospheric anomalies, e.g., during strong auroral activity or during re-entry of a spacecraft into the Earth's atmosphere. Technical failures Uptime being a key goal of most communications networks, power supplies and backup generators are typically used to ensure high-reliability power. Wireless networks may be subject to radio jamming; wired networks can be physically severed. Network design can also play a role in maintaining communications reliability; depending on the constraints in building a fiber-optic network, a self-healing ring topology may be used. Spacecraft reentry The communications blackouts that affect spacecraft re-entering the Earth's atmosphere, which are also known as radio blackouts, ionizatio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Beryllium-10
Beryllium-10 (10Be) is a radioactive isotope of beryllium. It is formed in the Earth's atmosphere mainly by cosmic ray spallation of nitrogen and oxygen. Beryllium-10 has a half-life of 1.39 × 106 years, and decays by beta decay to stable boron-10 with a maximum energy of 556.2 keV. It decays through the reaction 10Be→10B + e−. Light elements in the atmosphere react with high energy galactic cosmic ray particles. The spallation of the reaction products is the source of 10Be (t, u particles like n or p): :14N(t,5u)10Be; Example: 14N(n,p α)10Be :16O(t,7u)10Be Because beryllium tends to exist in solutions below about pH 5.5 (and rainwater above many industrialized areas can have a pH less than 5), it will dissolve and be transported to the Earth's surface via rainwater. As the precipitation quickly becomes more alkaline, beryllium drops out of solution. Cosmogenic 10Be thereby accumulates at the soil surface, where its relatively long half-life (1.387 million years) permi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Proxy (statistics)
In statistics, a proxy or proxy variable is a variable that is not in itself directly relevant, but that serves in place of an unobservable or immeasurable variable. In order for a variable to be a good proxy, it must have a close correlation, not necessarily linear, with the variable of interest. This correlation might be either positive or negative. Proxy variable must relate to an unobserved variable, must correlate with disturbance, and must not correlate with regressors once the disturbance is controlled for. Examples In social sciences, proxy measurements are often required to stand in for variables that cannot be directly measured. This process of standing in is also known as operationalization. Per-capita gross domestic product (GDP) is often used as a proxy for measures of standard of living or quality of life. Montgomery ''et al.'' examine several proxies used, and point out limitations with each, stating "In poor countries, no single empirical measure can be expected ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Solar Analog
Solar-type star, solar analogs (also analogues), and solar twins are stars that are particularly similar to the Sun. The stellar classification is a hierarchy with solar twin being most like the Sun followed by solar analog and then solar-type. Observations of these stars are important for understanding better the properties of the Sun in relation to other stars and the habitability of planets. By similarity to the Sun Defining the three categories by their similarity to the Sun reflects the evolution of astronomical observational techniques. Originally, solar-type was the closest that similarity to the Sun could be defined. Later, more precise measurement techniques and improved observatories allowed for greater precision of key details like temperature, enabling the creation of a solar analog category for stars that were particularly similar to the Sun. Later still, continued improvements in precision allowed for the creation of a solar-twin category for near-perfect matche ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stellar Population
During 1944, Walter Baade categorized groups of stars within the Milky Way into stellar populations. In the abstract of the article by Baade, he recognizes that Jan Oort originally conceived this type of classification in 1926: Baade noticed that bluer stars were strongly associated with the spiral arms, and yellow stars dominated near the central galactic bulge and within globular star clusters. Two main divisions were defined as * Population I and * Population II, with another newer, hypothetical division called * Population III added in 1978; they are often simply abbreviated as Pop. I, Pop. II, and Pop. III. Among the population types, significant differences were found with their individual observed stellar spectra. These were later shown to be very important and were possibly related to star formation, observed kinematics, stellar age, and even galaxy evolution in both spiral and elliptical galaxies. These three simple population classes use ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cosmogenic Isotope
Cosmogenic nuclides (or cosmogenic isotopes) are rare nuclides (isotopes) created when a high-energy cosmic ray interacts with the nucleus of an ''in situ'' Solar System atom, causing nucleons (protons and neutrons) to be expelled from the atom (see cosmic ray spallation). These nuclides are produced within Earth materials such as rocks or soil, in Earth's atmosphere, and in extraterrestrial items such as meteoroids. By measuring cosmogenic nuclides, scientists are able to gain insight into a range of geological and astronomical processes. There are both radioactive and stable cosmogenic nuclides. Some of these radionuclides are tritium, carbon-14 and phosphorus-32. Certain light (low atomic number) primordial nuclides (isotopes of lithium, beryllium and boron) are thought to have been created not only during the Big Bang, but also (and perhaps primarily) to have been made after the Big Bang, but before the condensation of the Solar System, by the process of cosmic ray ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Superflare
Superflares are very strong explosions observed on stars with energies up to ten thousand times that of typical solar flares. The stars in this class satisfy conditions which should make them solar analogues, and would be expected to be stable over very long time scales. The original nine candidates were detected by a variety of methods. No systematic study was possible until the launch of the Kepler space telescope, which monitored a very large number of solar-type stars with very high accuracy for an extended period. This showed that a small proportion of stars had violent outbursts, up to 10,000 times as powerful as the strongest flares known on the Sun. In many cases there were multiple events on the same star. Younger stars were more likely to flare than old ones, but strong events were seen on stars as old as the Sun. The flares were initially explained by postulating giant planets in very close orbits, such that the magnetic fields of the star and planet were linked. The orb ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Office Of Science And Technology Policy
An office is a space where an organization's employees perform administrative work in order to support and realize objects and goals of the organization. The word "office" may also denote a position within an organization with specific duties attached to it (see officer, office-holder, official); the latter is in fact an earlier usage, office as place originally referring to the location of one's duty. When used as an adjective, the term "office" may refer to business-related tasks. In law, a company or organization has offices in any place where it has an official presence, even if that presence consists of (for example) a storage silo rather than an establishment with desk-and- chair. An office is also an architectural and design phenomenon: ranging from a small office such as a bench in the corner of a small business of extremely small size (see small office/home office), through entire floors of buildings, up to and including massive buildings dedicated entirely t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
NARA
The National Archives and Records Administration (NARA) is an " independent federal agency of the United States government within the executive branch", charged with the preservation and documentation of government and historical records. It is also tasked with increasing public access to those documents which make up the National Archive. NARA is officially responsible for maintaining and publishing the legally authentic and authoritative copies of acts of Congress, presidential directives, and federal regulations. NARA also transmits votes of the Electoral College to Congress. It also examines Electoral College and Constitutional amendment ratification documents for prima facie legal sufficiency and an authenticating signature. The National Archives, and its publicly exhibited Charters of Freedom, which include the original United States Declaration of Independence, United States Constitution, United States Bill of Rights, and many other historical documents, is headquart ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Solar Storm Of 1859
The Carrington Event was the most intense geomagnetic storm in recorded history, peaking from 1 to 2 September 1859 during solar cycle 10. It created strong auroral displays that were reported globally and caused sparking and even fires in multiple 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 Christopher Carrington and Richard Hodgson—the first records of a solar flare. A geomagnetic storm of this magnitude occurring today would cause widespread electrical disruptions, blackouts, and damage due to extended outages of the electrical power grid. History The Carrington Event took place a few months before the solar maximum, a period of elevated solar activity, of solar cycle 10. Geomagnetic storm On 1†... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aurora
An aurora (plural: auroras or aurorae), also commonly known as the polar lights, is a natural light display in Earth's sky, predominantly seen in high-latitude regions (around 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 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 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 the amount of acceleration imp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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