Editing Space weather (section)

==Effects==
===Spacecraft electronics===
[[File:ExtremeEvent 20031026-00h 20031106-24h.jpg|thumb|right|320px|GOES-11 and GOES-12 monitored space weather conditions during the [[Halloween solar storms|October 2003 solar activity]]<ref name="Extreme Space Weather Events">{{cite web | title=Extreme Space Weather Events | publisher=[[National Geophysical Data Center]] | url=http://sxi.ngdc.noaa.gov/sxi_greatest.html| archive-url=https://web.archive.org/web/20011010173025/http://sxi.ngdc.noaa.gov/sxi_greatest.html| url-status=dead| archive-date=October 10, 2001}}</ref>]]

Some spacecraft failures can be directly attributed to space weather; many more are thought to have a space weather component. For example, 46 of the 70 failures reported in 2003 occurred during the October 2003 geomagnetic storm. The two most common adverse space weather effects on spacecraft are [[radiation damage]] and [[spacecraft charging]].

Radiation (high-energy particles) passes through the skin of the spacecraft and into the electronic components. In most cases, the radiation causes an erroneous signal or changes one bit in memory of a spacecraft's electronics ([[single event upset]]s). In a few cases, the radiation destroys a section of the electronics ([[latchup|single-event latchup]]).

Spacecraft charging is the accumulation of an [[electrostatic charge]] on a nonconducting material on the spacecraft's surface by low-energy particles. If enough charge is built up, a discharge (spark) occurs. This can cause an erroneous signal to be detected and acted on by the spacecraft computer. A recent study indicated that spacecraft charging is the predominant space weather effect on spacecraft in [[geosynchronous orbit]].<ref>{{cite journal|last=Choi|first=Ho-Sung |author2=J. Lee |author3=K.-S. Cho |author4=Y.-S. Kwak |author5=I.-H. Cho |author6=Y.-D. Park |author7=Y.-H. Kim |author8-link=Daniel N. Baker |author8=D. N. Baker |author9=G. D. Reeves |author10=D.-K. Lee |title=Analysis of GEO spacecraft anomalies: Space weather relationships|journal=Space Weather|year=2011|volume=9|issue=S06001|page=12|doi=10.1029/2010SW000597|s2cid=120192698 |doi-access=free |bibcode=2011SpWea...9.6001C }}</ref>

===Spacecraft orbit changes===
The orbits of spacecraft in [[low Earth orbit]] (LEO) decay to lower and lower altitudes due to the resistance from the friction between the spacecraft's surface (''i.e. '', drag) and the outer layer of the Earth's atmosphere (or the thermosphere and exosphere). Eventually, a LEO spacecraft falls out of orbit and towards the Earth's surface. Many spacecraft launched in the past few decades have the ability to fire a small rocket to manage their orbits. The rocket can increase altitude to extend lifetime, to direct the re-entry towards a particular (marine) site, or route the satellite to avoid collision with other spacecraft. Such maneuvers require precise information about the orbit. A geomagnetic storm can cause an orbit change over a few days that otherwise would occur over a year or more. The geomagnetic storm adds heat to the thermosphere, causing the thermosphere to expand and rise, increasing the drag on spacecraft. The [[2009 satellite collision]] between the ''Iridium 33'' and ''Cosmos 2251'' demonstrated the importance of having precise knowledge of all objects in orbit. ''Iridium 33'' had the capability to maneuver out of the path of ''Cosmos 2251 ''and could have evaded the crash, if a credible collision prediction had been available.

===Humans in space===
{{Main|Effect of spaceflight on the human body}}

The exposure of a human body to [[ionizing radiation]] has the same [[acute radiation syndrome|harmful effects]] whether the source of the radiation is a medical [[X-ray machine]], a [[nuclear power plant]], or radiation in space. The degree of the harmful effect depends on the length of exposure and the radiation's [[energy density]]. The ever-present [[radiation belt]]s extend down to the altitude of crewed spacecraft such as the [[International Space Station#Radiation|International Space Station]] (ISS) and the [[Space Shuttle]], but the amount of exposure is within the [[Spaceflight radiation carcinogenesis#Current Permissible Exposure Limits|acceptable lifetime exposure limit]] under normal conditions. During a major space weather event that includes an SEP burst, the [[flux]] can increase by orders of magnitude. Areas within ISS provide shielding that can keep the total dose within safe limits.<ref>{{Cite web|title = Space station radiation shields 'disappointing' - New Scientist|url = https://www.newscientist.com/article/dn2956-space-station-radiation-shields-disappointing.html|access-date = 2015-07-24}}</ref> For the [[Space Shuttle]], such an event would have required immediate mission termination.

===Ground systems===
====Spacecraft signals====
The ionosphere bends radio waves in the same manner that water in a pool bends visible light. When the medium through which such waves travel is disturbed, the light image or radio information is distorted and can become unrecognizable. The degree of distortion (scintillation) of a radio wave by the ionosphere depends on the signal frequency. Radio signals in the [[very high frequency|VHF]] band (30 to 300&nbsp;MHz) can be distorted beyond recognition by a disturbed ionosphere. Radio signals in the [[ultra high frequency|UHF]] band (300&nbsp;MHz to 3&nbsp;GHz) transit a disturbed ionosphere, but a receiver may not be able to keep locked to the carrier frequency. GPS uses signals at 1575.42&nbsp;MHz (L1) and 1227.6&nbsp;MHz (L2) that can be distorted by a disturbed ionosphere. Space weather events that corrupt GPS signals can significantly impact society. For example, the [[Wide Area Augmentation System]] <!-- (WAAS) --> operated by the US [[Federal Aviation Administration]] (FAA) is used as a navigation tool for North American commercial aviation. It is disabled by every major space weather event. Outages can range from minutes to days. Major space weather events can push the disturbed polar ionosphere 10° to 30° of latitude toward the equator and can cause large ionospheric gradients (changes in density over distance of hundreds of km) at mid and low latitude. Both of these factors can distort GPS signals.

===Long-distance radio signals===
Radio waves in the [[high frequency|HF]] band (3 to 30&nbsp;MHz) (also known as the [[shortwave]] band) are reflected by the ionosphere. Since the ground also reflects HF waves, a signal can be transmitted around the curvature of the Earth beyond the line of sight. During the 20th century, HF communications was the only method for a ship or aircraft far from land or a base station to communicate. The advent of systems such as [[Iridium satellite constellation|Iridium]] brought other methods of communications, but HF remains critical for vessels that do not carry the newer equipment and as a critical backup system for others. Space weather events can create irregularities in the ionosphere that scatter HF signals instead of reflecting them, preventing HF communications. At auroral and polar latitudes, small space weather events that occur frequently disrupt HF communications. At mid-latitudes, HF communications are disrupted by solar radio bursts, by X-rays from solar flares (which enhance and disturb the ionospheric D-layer) and by [[Total Electron Content|TEC]] enhancements and irregularities during major geomagnetic storms.

Trans[[polar route|polar airline route]]s are particularly sensitive to space weather, in part because [[Federal Aviation Regulations]] require reliable communication over the entire flight.<ref>FAA Advisory Circular 120-42B, June 6, 2008, Extended Operations (ETOPS and Polar Operations)</ref> Diverting such a flight is estimated to cost about $100,000.<ref name="nap.edu">{{Cite book|title = Severe Space Weather Events--Understanding Societal and Economic Impacts: A Workshop Report {{!}} The National Academies Press|doi = 10.17226/12507|year = 2008|isbn = 978-0-309-12769-1|last1 = Council|first1 = National Research|last2 = Sciences|first2 = Division on Engineering Physical|last3 = Board|first3 = Space Studies|last4 = Workshop|first4 = Committee on the Societal Economic Impacts of Severe Space Weather Events: A.}}</ref>

[[File:Aviation radiation environment.png|thumbnail|All passengers in commercial aircraft flying above {{convert|26,000|ft}} typically experience some exposure in this aviation radiation environment.]]

===Humans in commercial aviation ===
The magnetosphere guides cosmic ray and solar energetic particles to polar latitudes, while high-energy charged particles enter the mesosphere, stratosphere, and troposphere. These energetic particles at the top of the atmosphere shatter atmospheric atoms and molecules, creating harmful lower-energy particles that penetrate deep into the atmosphere and create measurable radiation. All aircraft flying above 8&nbsp;km (26,200 feet) altitude are exposed to these particles. The dose exposure is greater in polar regions than at midlatitude and equatorial regions. Many commercial aircraft fly over the polar region. When a space weather event causes radiation exposure to exceed the safe level set by aviation authorities,<ref>FAA Advisory Circular 120-52, March 5, 1990, Radiation exposure of air carrier crew members</ref> the aircraft's flight path is diverted.

Measurements of the radiation environment at commercial aircraft altitudes above 8&nbsp;km (26,000&nbsp;ft) have historically been done by instruments that record the data on board where the data are then processed later on the ground. However, a system of real-time radiation measurements on-board aircraft has been developed through the NASA Automated Radiation Measurements for Aerospace Safety (ARMAS) program.<ref>W. K., Tobiska, D. Bouwer, D. Smart, M. Shea, J. Bailey, L. Didkovsky, K. Judge, H. Garrett, W. Atwell, B. Gersey, R. Wilkins, D. Rice, R. Schunk, D. Bell, C. Mertens, X. Xu, M. Wiltberger, S. Wiley, E. Teets, B. Jones, S. Hong, K. Yoon, Global real-time dose measurements using the Automated Radiation Measurements for Aerospace Safety (ARMAS) system, Space Weather, 14, 1053-1080 (2016).</ref> [http://sol.spacenvironment.net/~ARMAS/ ARMAS] has flown hundreds of flights since 2013, mostly on research aircraft, and sent the data to the ground through Iridium satellite links. The eventual goal of these types of measurements is to data assimilate them into physics-based global radiation models, e.g., NASA's Nowcast of Atmospheric Ionizing Radiation System ([http://sol.spacenvironment.net/~nairas/index.html NAIRAS]), so as to provide the weather of the radiation environment rather than the climatology.

===Ground-induced electric fields===
[[Geomagnetic storm|Magnetic storm activity]] can induce geoelectric fields in the Earth's conducting [[lithosphere]].<ref>{{cite journal | doi = 10.1109/27.902215 | volume=28 | title=Geomagnetically induced currents during magnetic storms | year=2000 | journal=IEEE Transactions on Plasma Science | pages=1867–1873 | last1 = Pirjola | first1 = R.| issue=6 | bibcode=2000ITPS...28.1867P }}</ref> Corresponding voltage differentials can [[Geomagnetically induced current|find their way into electric power grids through ground connections]], driving uncontrolled electric currents that interfere with grid operation, damage transformers, trip protective relays, and sometimes cause blackouts.<ref>Extreme Space Weather: Impacts on Engineered Systems and Infrastructure, pp. 1-68. Roy. Acad. Engineer., London, UK (2013)</ref> This complicated chain of causes and effects was demonstrated during [[March 1989 geomagnetic storm|the magnetic storm of March 1989]],<ref>{{cite journal | last1 = Allen | first1 = J. | last2 = Frank | first2 = L. | last3 = Sauer | first3 = H. | last4 = Reiff | first4 = P. | title = (1989) Effects of the March 1989 solar activity | journal = EOS Trans. Am. Geophys. Union | volume = 70 | issue = 1479| pages = 1486–1488 }}</ref> which caused the complete collapse of the [[Hydro-Québec]] electric-power grid in Canada, temporarily leaving nine million people without electricity. The possible occurrence of an even more intense storm<ref>Baker, D.N., Balstad, R., Bodeau, J.M., Cameron, E., Fennell, J.E., Fisher, G.M., Forbes, K.F., Kintner, P.M., Leffler, L.G., Lewis, W.S., Reagan, J.B., Small, A.A., Stansell, T.A., Strachan, L.: Severe Space Weather Events: Understanding Societal and Economic Impacts, pp. 1-144, The National Academy Press, Washington, DC (2008)</ref> led to operational standards intended to mitigate induction-hazard risks, while [[reinsurance]] companies commissioned revised [[risk assessments]].<ref>Lloyd's: Emerging Risk Report: Solar Storm Risk to the North American Electric Grid, pp. 1--22. Lloyd's of London, London, UK (2013)</ref>

===Geophysical exploration===
Air- and ship-borne [[aeromagnetic survey|magnetic surveys]] can be affected by rapid magnetic field variations during geomagnetic storms. Such storms cause data-interpretation problems because the space weather-related magnetic field changes are similar in magnitude to those of the subsurface crustal magnetic field in the survey area. Accurate geomagnetic storm warnings, including an assessment of storm magnitude and duration, allows for an economic use of survey equipment.

===Geophysics and hydrocarbon production===
For economic and other reasons, oil and gas production often involves [[directional drilling|horizontal drilling]] of well paths many kilometers from a single wellhead. Accuracy requirements are strict, due to target size – reservoirs may only be a few tens to hundreds of meters across – and safety, because of the proximity of other boreholes. The most accurate gyroscopic method is expensive, since it can stop drilling for hours. An alternative is to use a magnetic survey, which enables [[MWD (measurement while drilling)|measurement while drilling (MWD)]]. Near real-time magnetic data can be used to correct drilling direction.<ref>Clark, T.D.G., Clarke, E. Space weather services for the offshore drilling industry, in: Proceedings of the ESA Space Weather Workshop, ESTEC, the Netherlands, 17–19 Dec, 2001, ESA WPP-194, 2001.; Reay et al., 2006</ref><ref>{{cite journal | doi = 10.1016/j.asr.2005.04.082 | volume=37 | title=Large-magnitude geomagnetic disturbances in the North Sea region: Statistics, causes, and forecasting | year=2006 | journal=Advances in Space Research | pages=1169–1174 | last1 = Gleisner | first1 = Hans| issue=6 | bibcode=2006AdSpR..37.1169G }}</ref> Magnetic data and space weather forecasts can help to clarify unknown sources of drilling error.

===Terrestrial weather===
The amount of energy entering the troposphere and stratosphere from space weather phenomena is trivial compared to the solar [[insolation]] in the visible and infrared portions of the solar electromagnetic spectrum. Although some linkage between the 11-year sunspot cycle and the Earth's [[climate]] has been claimed.,<ref>Variability of the solar cycle length during the past five centuries and the apparent association with terrestrial climate, K. Lassen and E. Friis-Christensen, 57, 8, pp. 835–845, 1995</ref> this has never been verified. For example, the [[Maunder minimum]], a 70-year period almost devoid of sunspots, has often been suggested to be correlated to a cooler climate, but these correlations have disappeared after deeper studies. The suggested link from changes in cosmic-ray flux causing changes in the amount of cloud formation<ref>What do we really know about the Sun-climate connection?, E. Friis-Christensen and H. Svensmark, Adv. Space Res., 20, 4/5, pp. 913–921, 1997.</ref> did not survive scientific tests. Another suggestion, that variations in the [[extreme ultraviolet]] (EUV) flux subtly influence existing drivers of the climate and tip the balance between [[El Niño]]/[[La Niña]] events<ref>Amplifying the Pacific climate system response to a small 11-year solar cycle forcing, Meehl, G.A.; Arblaster, J.M.; Matthes, K.; Sassi, F.; van Loon, H., ''Science'', 325, 5944, 1114-18, 28 Aug. 2009</ref> collapsed when new research showed this was not possible. As such, a linkage between space weather and the climate has not been demonstrated.

In addition, a link has been suggested between high energy charged particles (such as [[Solar Energetic Particle|SEPs]] and [[cosmic rays]]) and [[cloud formation]]. This is because charged particles interact with the atmosphere to produce [[Volatile (astrogeology)|volatiles]] which then condense, creating [[cloud seeds]].<ref>{{Cite journal| doi = 10.1038/news.2011.504| issn = 1476-4687| last = Brumfiel| first = Geoff| title = Cloud formation may be linked to cosmic rays| journal = Nature| date = 2011-08-24}}</ref> This is a topic of ongoing research at [[CERN]], where experiments test the effect of high-energy charged particles on atmosphere.<ref>{{cite web|url=https://home.cern/news/news/experiments/cosmic-rays-clouds|publisher=CERN|last=Lopes|first=Ana|year=2019|title=Cloud formation may be linked to cosmic rays}}</ref> If proven, this may suggest a link between space weather (in the form of [[solar particle event]]s) and cloud formation.<ref>{{cite web|url=http://news.bbc.co.uk/1/hi/sci/tech/2333133.stm|last=Kirby|first=Alex|publisher=BBC|year=2002|title=Cosmic rays 'linked to clouds'}}</ref>

Most recently, a statistical connection has been reported between the occurrence of heavy [[floods]] and the arrivals of high-speed [[solar wind]] streams (HSSs). The enhanced [[auroral]] energy deposition during HSSs is suggested as a mechanism for the generation of downward propagating [[atmospheric]] [[gravity waves]] (AGWs). As AGWs reach lower [[atmosphere]], they may excite the conditional [[instability]] in the [[troposphere]], thus leading to excessive rainfall. <ref>{{Cite journal| doi = 10.3389/fspas.2023.1359458| last1 = Barta| first1 = Veronika| last2 = Chum |first2 = Jaroslav| last3 = Liu |first3 = Han-Li| last4 = Pokhotelov |first4 = Dimitry | last5 = Stober |first5 = Gunter |title = Editorial for the Special Issue: Vertical Coupling in the Atmosphere-Ionosphere-Magnetosphere System| journal = Frontiers in Astronomy and Space Sciences| date = 2024-01-16| volume = 10| doi-access = free}}</ref>