Ring current

<h2 id="earths-ring-current">Earth's ring current</h2>

<p><a href="/facts/Earth/HLLmDfj0">Earth</a>'s ring current is responsible for shielding the lower latitudes of the Earth from magnetospheric electric fields. It therefore has a large effect on the electrodynamics of <a href="/facts/Geomagnetic_storm/4rD8DSlm">geomagnetic storms</a>. The ring current system consists of a band, at a distance of 3 to 8 <a href="/facts/Earth_radius/PVsf0g2I"><i>R</i>E</a>,<a class="footnote-ref" id="fnref:1" href="#fn:1"><sup>1</sup></a> which lies in the <a href="/facts/Celestial_sphere/TYAtXgor">equatorial plane</a> and circulates clockwise around the Earth (when viewed from the north). The particles of this region produce a magnetic field in opposition to the <a href="/facts/Earth%2527s_magnetic_field/73G36wmx">Earth's magnetic field</a> and so an Earthly observer would observe a decrease in the <a href="/facts/Magnetic_field/Ta8Ev588">magnetic field</a> in this area.<a class="footnote-ref" id="fnref:2" href="#fn:2"><sup>2</sup></a>: 135  The negative deflection of the Earth's magnetic field due to the ring current is measured by the <a href="/facts/Dst_index/jz7zRtNo">Dst index</a>.
</p><p>The ring current energy is mainly carried around by the ions, most of which are protons. However, one also sees alpha particles in the ring current, a type of ion that is plentiful in the solar wind. In addition, a certain percentage are O+ oxygen ions, similar to those in the ionosphere of Earth, though much more energetic. This mixture of ions suggests that ring current particles probably come from more than one source.
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<h2 id="the-ring-current-and-geomagnetic-storms">The ring current and geomagnetic storms</h2>
<p>During a <a href="/facts/Geomagnetic_storm/4rD8DSlm">geomagnetic storm</a>, the number of particles in the ring current will increase. As a result, there is a decrease in the effects of <a href="/facts/Earth%2527s_magnetic_field/73G36wmx">geomagnetic field</a>.
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<h2 id="see-also">See also</h2>
<ul><li><a href="/facts/Van_Allen_radiation_belt/XKnhnWK0">Van Allen radiation belt</a></li></ul>

<ul><li><a href="/facts/Janet_Kozyra/Sp4h7KYy">Janet U. Kozyra</a> & Michael W. Liemohn (2003). <a href="http://www-personal.umich.edu/~liemohn/Reprints/Kozyra_SSR_2003.pdf">"Ring Current Energy Input and Decay"</a> (PDF). <i>Space Science Reviews</i>. 109 (1–4): 105–131. <a href="/facts/Bibcode_(identifier)/9HtdQSGB">Bibcode</a>:<a href="https://ui.adsabs.harvard.edu/abs/2003SSRv..109..105K">2003SSRv..109..105K</a>. <a href="/facts/Doi_(identifier)/muM9Etpq">doi</a>:<a href="https://doi.org/10.1023%2FB%3ASPAC.0000007516.10433.ad">10.1023/B:SPAC.0000007516.10433.ad</a>. <a href="/facts/Hdl_(identifier)/rdebSxmC">hdl</a>:<a href="https://hdl.handle.net/2027.42%2F43761">2027.42/43761</a>. <a href="/facts/S2CID_(identifier)/ldJsHa2Y">S2CID</a> <a href="https://api.semanticscholar.org/CorpusID:53598767">53598767</a>.</li></ul>

<h2 id="references">References</h2>

<ol>
<li id="fn:1"><p>I. A. Daglis; R. M. Thorne; W. Baumjohann & S. Orsini (November 1999). "The terrestrial ring current: Origin, formation, and decay". Reviews of Geophysics. 37 (4): 407–438. Bibcode:1999RvGeo..37..407D. doi:10.1029/1999RG900009. <a href="https://doi.org/10.1029%2F1999RG900009" target="_blank">https://doi.org/10.1029%2F1999RG900009</a> <a href="#fnref:1" class="footnote-back-ref">↩</a></p></li>
<li id="fn:2"><p>Ronald T. Merrill (15 November 2010). Our Magnetic Earth: The Science of Geomagnetism. University of Chicago Press. ISBN 978-0-226-52050-6. <a href="978-0-226-52050-6" target="_blank">978-0-226-52050-6</a> <a href="#fnref:2" class="footnote-back-ref">↩</a></p></li>
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Ring current open-in-new

Ring current