disturbance storm time index
{{Short description|Measure of the Earth's ring current}}
The disturbance storm time index, also known as the Dst index or Kyoto Dst index, is a measure of the strength of the Earth's ring current.{{cite book |last1=Maynaud |first1=P. N. |title=Derivation, Meaning, and Use of Geomagnetic Indices |series=Geophysical Monograph Series |volume=22 |date=1980 |publisher=American Geophysical Union |location=Washington, D.C. |isbn=9781118663837 |doi=10.1029/GM022 |bibcode=1980GMS....22..607M}}{{rp|115}}{{cite journal |last1=Loewe |first1=C. A. |last2=Prölss |first2=G. W. |title=Classification and mean behavior of magnetic storms |journal=Journal of Geophysical Research: Space Physics |date=1997 |volume=102 |issue=A7 |pages=14209-14213 |doi=10.1029/96JA04020 |bibcode=1997JGR...10214209L}}
The ring current around Earth produces a magnetic field that is directly opposite Earth's magnetic field; that is, if the difference between solar electrons and protons gets higher, then Earth's magnetic field becomes weaker.
A negative Dst value means that Earth's magnetic field is weakened. This is particularly the case during solar storms.
Its units are typically measured in nT (nano-Tesla).
See also
References
External links
- The [http://wdc.kugi.kyoto-u.ac.jp/dstdir/ Dst index homepage] provided by Kyoto University
- Dst at [http://www.ngdc.noaa.gov/stp/GEOMAG/dst.html NOAA/NGDC]
- Dst as part of SWENET [http://www.esa-spaceweather.net/swenet/login?cmd=swenet_latest_alerts Latest Alerts] {{Webarchive|url=https://web.archive.org/web/20120209110443/http://www.esa-spaceweather.net/swenet/login?cmd=swenet_latest_alerts |date=2012-02-09 }} (on ESA's Space Weather Portal)
{{Solar storms}}
{{DEFAULTSORT:Disturbance Storm Time Index}}
Category:Radio frequency propagation
Category:Electric and magnetic fields in matter
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