Aurora: 2022’s breathtaking new thriller of the lengths one family must take to survive a worldwide blackout

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Auroras are more frequent and brighter during the intense phase of the solar cycle when coronal mass ejections increase the intensity of the solar wind. [59] Magnetosphere [ edit ] Schematic of Earth's magnetosphere Red: At its highest altitudes, excited atomic oxygen emits at 630nm (red); low concentration of atoms and lower sensitivity of eyes at this wavelength make this color visible only under more intense solar activity. The low number of oxygen atoms and their gradually diminishing concentration is responsible for the faint appearance of the top parts of the "curtains". Scarlet, crimson, and carmine are the most often-seen hues of red for the auroras.

Schield, M. A.; Freeman, J. W.; Dessler, A. J. (1969). "A Source for Field-Aligned Currents at Auroral Latitudes". Journal of Geophysical Research. 74 (1): 247–256. Bibcode: 1969JGR....74..247S. doi: 10.1029/JA074i001p00247. Orr, L.; Chapman, S. C.; Gjerloev, J. W.; Guo, W. (23 March 2021). "Network community structure of substorms using SuperMAG magnetometers, L. Orr, S. C. Chapman, J. W. Gjerloev & W. Guo". Nature Communications. 12 (1): 1842. doi: 10.1038/s41467-021-22112-4. PMC 7988152. PMID 33758181. Pokhotelov, D. (2002). Effects of the active auroral ionosphere on magnetosphere-ionosphere coupling (PhD Thesis). Dartmouth College. doi: 10.1349/ddlp.3332. Most of the planets in the Solar System, some natural satellites, brown dwarfs, and even comets also host auroras. 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 imparted to the precipitating particles.That aurora is thought to have been produced by one of the most intense coronal mass ejections in history. It is also notable for the fact that it is the first time where the phenomena of auroral activity and electricity were unambiguously linked. This insight was made possible not only due to scientific magnetometer measurements of the era, but also as a result of a significant portion of the 125,000 miles (201,000km) of telegraph lines then in service being significantly disrupted for many hours throughout the storm. Some telegraph lines, however, seem to have been of the appropriate length and orientation to produce a sufficient geomagnetically induced current from the electromagnetic field to allow for continued communication with the telegraph operator power supplies switched off. [74] The following conversation occurred between two operators of the American Telegraph Line between Boston and Portland, Maine, on the night of 2 September 1859 and reported in the Boston Traveler:

In the case of diffuse auroras, the electron pitch angles are altered by their interaction with various plasma waves. Each interaction 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 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. A variety of Native American myths surround the spectacle. The European explorer Samuel Hearne traveled with Chipewyan Dene in 1771 and recorded their views on the ed-thin ('caribou'). According to Hearne, the Dene people saw the resemblance between an aurora and the sparks produced when caribou fur is stroked. They believed that the lights were the spirits of their departed friends dancing in the sky, and when they shone brightly it meant that their deceased friends were very happy. [92] 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. [50] Protons are also associated with auroras, both discrete and diffuse.

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N. (2003). "Observations of non-conjugate theta aurora". Geophysical Research Letters. 30 (21): 2125. Bibcode: 2003GeoRL..30.2125O. doi: 10.1029/2003GL017914. Eyes on the Aurora, Part 2: What is a Keogram?". Aurorasaurus. 9 September 2020 . Retrieved 26 February 2022.

Størmer, Carl (1946). "Frequency of 12,330 measured heights of aurora from southern Norway in the years 1911–1944". Terrestrial Magnetism and Atmospheric Electricity. 51 (4): 501–504. Bibcode: 1946TeMAE..51..501S. doi: 10.1029/te051i004p00501. Clarke, J. (1910), Physical Science in the time of Nero, pp. 39–41, London: Macmillan, accessed 1 January 2017. As Archbishop of York, Stephen Cottrell, writes in his foreword to the book, Advent is not only a time for anticipating the moment Jesus Christ came into the world but also reflecting on the ‘last things’ foretold in the Book of Revelation where people of every tribe, tongue and nation rejoice before the throne of God. Q. Choi, Charles (29 July 2015). "First Alien Auroras Found, Are 1 Million Times Brighter Than Any on Earth". space.com . Retrieved 29 July 2015.

Andrews, Robin George (3 May 2019). "Steve the odd 'aurora' revealed to be two sky shows in one". National Geographic. Archived from the original on 4 May 2019 . Retrieved 4 May 2019.