SUMMARY / RELATED TOPICS

Coronal mass ejection

A coronal mass ejection is a significant release of plasma and accompanying magnetic field from the solar corona. They follow solar flares and are present during a solar prominence eruption; the plasma is released into the solar wind, can be observed in coronagraph imagery. Coronal mass ejections are associated with other forms of solar activity, but a broadly accepted theoretical understanding of these relationships has not been established. CMEs most originate from active regions on the Sun's surface, such as groupings of sunspots associated with frequent flares. Near solar maxima, the Sun produces about three CMEs every day, whereas near solar minima, there is about one CME every five days; the largest recorded geomagnetic perturbation, resulting from a CME hitting the Earth's magnetosphere, was the solar storm of 1859, which took down parts of the created US telegraph network, starting fires and shocking some telegraph operators. Some telegraphers, on the other hand, were able to continue operating with their batteries disconnected, powered by the aurora-induced currents in the lines, with normal or improved signal quality.

A pair in Portland and Boston, conversed in this way for nearly two hours at the height of the storm, without any manmade power supply. Coronal mass ejections release large quantities of matter and electromagnetic radiation into space above the Sun's surface, either near the corona, or farther into the planetary system, or beyond; the ejected material is a magnetized plasma consisting of electrons and protons. While the terrestrial effects of solar flares are fast, CMEs are slow, developing at the Alfvén speed. Coronal mass ejections are associated with enormous changes and disturbances in the coronal magnetic field, they are observed with a white-light coronagraph. The phenomenon of magnetic reconnection is associated with CMEs and solar flares. In magnetohydrodynamic theory, the sudden rearrangement of magnetic field lines when two oppositely directed magnetic fields are brought together is called "magnetic reconnection". Reconnection releases energy stored in the original stressed magnetic fields.

These magnetic field lines can become twisted in a helical structure, with a'right-hand twist' or a'left hand twist'. As the Sun's magnetic field lines become more and more twisted, CMEs appear to be a'valve' to release the magnetic energy being built up, as evidenced by the helical structure of CMEs, that would otherwise renew itself continuously each solar cycle and rip the Sun apart. On the Sun, magnetic reconnection may happen on solar arcades—a series of occurring loops of magnetic lines of force; these lines of force reconnect into a low arcade of loops, leaving a helix of magnetic field unconnected to the rest of the arcade. The sudden release of energy during this process causes the solar flare and ejects the CME; the helical magnetic field and the material that it contains may violently expand outwards forming a CME. This explains why CMEs and solar flares erupt from what are known as the active regions on the Sun where magnetic fields are much stronger on average; when the ejection is directed towards Earth and reaches it as an interplanetary CME, the shock wave of traveling mass causes a geomagnetic storm that may disrupt Earth's magnetosphere, compressing it on the day side and extending the night-side magnetic tail.

When the magnetosphere reconnects on the nightside, it releases power on the order of terawatt scale, directed back toward Earth's upper atmosphere. Solar energetic particles can cause strong aurorae in large regions around Earth's magnetic poles; these are known as the Northern Lights in the northern hemisphere, the Southern Lights in the southern hemisphere. Coronal mass ejections, along with solar flares of other origin, can disrupt radio transmissions and cause damage to satellites and electrical transmission line facilities, resulting in massive and long-lasting power outages. Energetic protons released by a CME can cause an increase in the number of free electrons in the ionosphere in the high-latitude polar regions; the increase in free electrons can enhance radio wave absorption within the D-region of the ionosphere, leading to Polar Cap Absorption events. Humans at high altitudes, as in airplanes or space stations, risk exposure to intense solar particle events; the energy absorbed by astronauts is not reduced by a typical spacecraft shield design and, if any protection is provided, it would result from changes in the microscopic inhomogeneity of the energy absorption events.

A typical coronal mass ejection may have any or all of three distinctive features: a cavity of low electron density, a dense core, a bright leading edge. Most ejections originate from active regions on the Sun's surface, such as groupings of sunspots associated with frequent flares; these regions have closed magnetic field lines, in which the magnetic field strength is large enough to contain the plasma. These field lines must be weakened for the ejection to escape from the Sun. However, CMEs may be initiated in quiet surface regions, although in many cases the quiet region was active. During solar minimum, CMEs form in the coronal streamer belt near the solar magnetic equator. During solar maximum, they originate from active regions whose latitudinal distribution is more homogeneous. Coronal mass ejections reach velocities from 20 t

Nicholas Héroys

Nicholas Héroys was an English chartered accountant and amateur cricketer who played in one first-class cricket match for Cambridge University Cricket Club in 1960. Héroys was born at Marylebone in London, the son of Vladmir and Sheila Héroys, educated at Tonbridge School in Kent. After leaving school he was commissioned in the Royal Leicestershire Regiment and completed his National Service before going up to Cambridge University, he played cricket and rackets at cricket for teams at University. His only appearance for the University side itself came in a first-class match against Hampshire County Cricket Club in May 1960. Professionally Héroys worked for printing company McCorquodale, joining the company board in 1978, becoming their Finance Director and, in 1985, chairman of Wisden Group after McCorquodale bought the group, he finished his career as Finance Director of Slaughter and May, was a General Committee member of Kent County Cricket Club for over 30 years starting in 1970 and was President of the club in 1995–96.

He played club cricket for Old Tonbridgians, captaining the team to five finals of The Cricketer Cup. Héroys was married to his wife, for more than 50 years and had two sons, he died in January 2019 aged 81. Nicholas Héroys at ESPNcricinfo

George Alonzo Johnson

George Alonzo Johnson 49er, Colorado River steamboat entrepreneur, California politician. George Alonzo Johnson was born in August 1824, in Palatine Bridge, Montgomery County, New York. In 1849 as a sailor he heard of the discovery of gold and left New York drawn by the California Gold Rush and came to San Francisco, in June 1849. There he worked unloading ships, except for a short trip to the mines, until May 1850. Hearing news of the Glanton Massacre he got together a small group of partners, with things necessary to build a ferry and traveled to the Yuma Crossing via San Diego. There they built and began operating a ferry sold it and returned to San Francisco. Seeing the opportunity in bringing supplies to the isolated post of Fort Yuma, in 1852 Johnson and his partner Benjamin M. Hartshorne contracted to carry supplies up the Colorado in poled barges; this failed due to the strong many sandbars in the river. After a steam tug, the 20 hp Uncle Sam was used to ascend the river in 1853, Johnson formed George A. Johnson & Company with Hartshorne and another partner Captain Alfred H. Wilcox.

They brought the disassembled side-wheel steamboat General Jesup to the Colorado River Delta. There in the estuary he assembled this more powerful 70 hp steamboat and began shipping cargo and carrying passengers on the Colorado River from its mouth, up to Fort Yuma, his steamboat carried 50 tons of cargo to the fort in 5 days and brought the cost to supply the fort down to $75 a ton from the $500 a ton shipped across the desert from San Diego. It made the Company $4,000 per trip to ships in the mouth of the Colorado River. Johnson was instrumental in getting Congressional funding for a military expedition to explore the Colorado River above Fort Yuma in 1856. Cut out of providing the steamboat for the 1857 expedition of Lt. Ives, Johnson at his own expense took the General Jesup up river first exploring the river up to what is now Nevada; as the only steamboat company on the river and his partners became wealthy after the discovery of gold along the Colorado River in 1858. In 1858 he moved to San Diego, where he married a famous beauty, Maria Estéfana Alvarado on June 4, 1859 in San Diego, California.

Her parents gave Johnson's wife the Rancho Santa Maria de Los Peñasquitos as a wedding present. Johnson built a home in Yuma for his wife for when they traveled there, that became the commanding officers quarters of the Yuma Quartermaster Depot in 1864; the Johnsons had nine children. In 1863, Johnson became a Member of the California State Assembly for the 1st District, again in 1866-67. Johnson had delegated operations to his senior steamboat captain Issac Polhamus, distracted by his rancho and political career did not invest in more shipping to keep up with the growing traffic caused by the 1862 Colorado River gold rush. By 1864 it had created a large backlog of undelivered freight and caused competition of opposition lines to arrive on the Colorado River; this forced Johnson to expand his fleet of steamboats and to begin to use barges to increase their cargo carrying capacity. Following a price war that lasted until 1866, with the advantage of the contracts to supply the U. S. Army posts and his system of wood-yards, Johnson's company was again the only steamboat company on the river.

In 1869 he incorporated his steamboat company as the Colorado Steam Navigation Company which he and his partners held until they sold its steamboats to the Southern Pacific Railroad in 1877. Johnson acquired title to the Rancho Los Peñasquitos when the U. S. government granted a patent to the land in 1876. In 1880, the Johnsons lost their rancho to creditors and within several years moved to a building, now known as the Johnson House, which they owned on the plaza of San Diego where they remained until his death, he was buried in San Diego. George Alonzo Johnson From Society of California Pioneers. Print from copy neg. loaned by Denis Casebier 1969, Nov. 07, in The Otis Marston Colorado River Collection, Huntington Digital Library