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<front>
<journal-meta>
<journal-id journal-id-type="publisher">NPG</journal-id>
<journal-title-group>
<journal-title>Nonlinear Processes in Geophysics</journal-title>
<abbrev-journal-title abbrev-type="publisher">NPG</abbrev-journal-title>
<abbrev-journal-title abbrev-type="nlm-ta">Nonlin. Processes Geophys.</abbrev-journal-title>
</journal-title-group>
<issn pub-type="epub">1607-7946</issn>
<publisher><publisher-name>Copernicus Publications</publisher-name>
<publisher-loc>Göttingen, Germany</publisher-loc>
</publisher>
</journal-meta>
<article-meta>
<article-id pub-id-type="doi">10.5194/npg-8-175-2001</article-id>
<title-group>
<article-title>An example of resonances, coherent structures and topological phase transitions - the origin of the low frequency broadband spectrum in the auroral zone</article-title>
</title-group>
<contrib-group><contrib contrib-type="author" xlink:type="simple"><name name-style="western"><surname>Chang</surname>
<given-names>T.</given-names>
</name>
<xref ref-type="aff" rid="aff1">
<sup>1</sup>
</xref>
</contrib>
</contrib-group><aff id="aff1">
<label>1</label>
<addr-line>Center for Space Research, Massachusetts Institute of Technology Cambridge, MA 02139, USA</addr-line>
</aff>
<pub-date pub-type="epub">
<day>30</day>
<month>06</month>
<year>2001</year>
</pub-date>
<volume>8</volume>
<issue>3</issue>
<fpage>175</fpage>
<lpage>180</lpage>
<permissions>
<copyright-statement>Copyright: &#x000a9; 2001 T. Chang</copyright-statement>
<copyright-year>2001</copyright-year>
<license license-type="open-access">
<license-p>This work is licensed under the Creative Commons Attribution-NonCommercial-ShareAlike 2.5 Generic License. To view a copy of this licence, visit <ext-link ext-link-type="uri"  xlink:href="https://creativecommons.org/licenses/by-nc-sa/2.5/">https://creativecommons.org/licenses/by-nc-sa/2.5/</ext-link></license-p>
</license>
</permissions>
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<self-uri xlink:href="https://npg.copernicus.org/articles/8/175/2001/npg-8-175-2001.pdf">The full text article is available as a PDF file from https://npg.copernicus.org/articles/8/175/2001/npg-8-175-2001.pdf</self-uri>
<abstract>
<p>We consider the
      phenomena of intermittent turbulence in magnetized space plasmas from the
      point of view of topological phase transitions involving the merging and
      interactions of anisotropic coherent structures. The stochastic behaviour
      of these coherent plasma structures can undergo complex changes as the
      dynamic system evolves, similar to those commonly observed in (first and
      second order) equilibrium phase transitions. When conditions are
      favourable, such topological entities can evolve into a state of forced
      and/or self-organized criticality (FSOC). As an example, we apply these
      ideas to the understanding of the origin of the commonly observed
      broadband power-law low frequency electric field spectral densities and
      the characteristic filamentary current structures in the auroral zone. The
      broadband turbulence can provide efficient resonant energization of the
      ionospheric oxygen ions.</p>
</abstract>
<counts><page-count count="6"/></counts>
</article-meta>
</front>
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