Editing Cosmic noise (section)

== Sources of cosmic noise ==
Cosmic noise refers to the [[Radio frequency|background radio frequency]] radiation from [[Galaxy|galactic sources]], which have constant intensity during [[geomagnetic]]ally quiet periods.<ref name=":2">{{Cite journal |date=2018-06-01 |title=Solar flare induced cosmic noise absorption |journal=NRIAG Journal of Astronomy and Geophysics |language=en |volume=7 |issue=1 |pages=31–39 |doi=10.1016/j.nrjag.2018.03.002 |issn=2090-9977 |doi-access=free |last1=Ogunmodimu |first1=Olugbenga |last2=Honary |first2=Farideh |last3=Rogers |first3=Neil |last4=Falayi |first4=E. O. |last5=Bolaji |first5=O. S. |bibcode=2018JAsGe...7...31O}}</ref>

=== Sun flares ===
Cosmic noise can be traced from [[solar flares]], which are sudden explosive releases of stored [[magnetic energy]] in the atmosphere of the Sun, causing sudden brightening of the [[photosphere]]. Solar flares can last from a few minutes to several hours.

During solar flare events, particles and electromagnetic emissions can affect [[Earth]]'s atmosphere by fluctuating the level of [[ionization]] in the Earth's [[ionosphere]]. Increased ionization results in absorption of the cosmic radio noise as it passes through the ionosphere.

=== Solar wind ===
[[Solar wind]] is a flux of particles, [[proton]]s and [[electron]]s together with [[Atomic nucleus|nuclei]] of heavier elements in smaller numbers, that are accelerated by the high temperatures of the [[solar corona]] to velocities large enough to allow them to escape from the Sun's gravitational field.<ref>{{Cite web |title=Solar wind |url=https://www.britannica.com/science/solar-wind |access-date=2021-04-09 |website=Encyclopedia Britannica |language=en}}</ref>

Solar wind causes sudden bursts of cosmic noise absorption in the Earth's ionosphere. These bursts can only be detected only if the magnitude of the geomagnetic field perturbation caused by the solar wind shock is large enough.<ref>{{cite journal |last1=Osepian |first1=A. |last2=Kirkwood |first2=S. |title=Cosmic radio-noise absorption bursts caused by solar wind shocks |journal=Annales Geophysicae |date=7 September 2004 |volume=22 |issue=8 |pages=2973–2987 |doi=10.5194/angeo-22-2973-2004 |bibcode=2004AnGeo..22.2973O |s2cid=55842333 |url=https://angeo.copernicus.org/articles/22/2973/2004/angeo-22-2973-2004.pdf |archive-url=https://web.archive.org/web/20200921072326/https://angeo.copernicus.org/articles/22/2973/2004/angeo-22-2973-2004.pdf |archive-date=2020-09-21 |url-status=live |access-date=9 November 2022 |language=en |doi-access=free }}</ref>