https://sprg.ssl.berkeley.edu/~tohban/wiki/index.php?title=Revisiting_the_SHH_and_SEP_Link&feed=atom&action=historyRevisiting the SHH and SEP Link - Revision history2024-03-29T09:12:49ZRevision history for this page on the wikiMediaWiki 1.16.0https://sprg.ssl.berkeley.edu/~tohban/wiki/index.php?title=Revisiting_the_SHH_and_SEP_Link&diff=10685&oldid=prevSchriste at 16:35, 22 August 20182018-08-22T16:35:50Z<p></p>
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<tr><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"><div>|second_author = S&auml;m Krucker</div></td><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"><div>|second_author = S&auml;m Krucker</div></td></tr>
<tr><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"><div>|publish_date = 15 February 2010</div></td><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"><div>|publish_date = 15 February 2010</div></td></tr>
<tr><td class='diff-marker'>-</td><td style="background: #ffa; color:black; font-size: smaller;"><div>|next_nugget = <del class="diffchange diffchange-inline">Orthogonal bursts</del></div></td><td class='diff-marker'>+</td><td style="background: #cfc; color:black; font-size: smaller;"><div>|next_nugget=<ins class="diffchange diffchange-inline">{{#ask: [[Category:Nugget]] [[RHESSI Nugget Index::122]]}}</ins></div></td></tr>
<tr><td class='diff-marker'>-</td><td style="background: #ffa; color:black; font-size: smaller;"><div>|previous_nugget = [[<del class="diffchange diffchange-inline">Two phases of X-ray emission in a solar eruptive flare</del>]]</div></td><td class='diff-marker'>+</td><td style="background: #cfc; color:black; font-size: smaller;"><div>|previous_nugget=<ins class="diffchange diffchange-inline">{{#ask: [[Category:Nugget]] </ins>[[<ins class="diffchange diffchange-inline">RHESSI Nugget Index::120</ins>]]<ins class="diffchange diffchange-inline">}}</ins></div></td></tr>
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</table>Schristehttps://sprg.ssl.berkeley.edu/~tohban/wiki/index.php?title=Revisiting_the_SHH_and_SEP_Link&diff=2651&oldid=prevHhudson at 19:43, 1 March 20102010-03-01T19:43:17Z<p></p>
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<tr><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"><div>|publish_date = 15 February 2010</div></td><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"><div>|publish_date = 15 February 2010</div></td></tr>
<tr><td class='diff-marker'>-</td><td style="background: #ffa; color:black; font-size: smaller;"><div>|next_nugget = <del class="diffchange diffchange-inline">Hard X-ray waiting times</del></div></td><td class='diff-marker'>+</td><td style="background: #cfc; color:black; font-size: smaller;"><div>|next_nugget = <ins class="diffchange diffchange-inline">Orthogonal bursts</ins></div></td></tr>
<tr><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"><div>|previous_nugget = [[Two phases of X-ray emission in a solar eruptive flare]]</div></td><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"><div>|previous_nugget = [[Two phases of X-ray emission in a solar eruptive flare]]</div></td></tr>
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</table>Hhudsonhttps://sprg.ssl.berkeley.edu/~tohban/wiki/index.php?title=Revisiting_the_SHH_and_SEP_Link&diff=2646&oldid=prevSchriste: /* Spectral Analysis */2010-02-26T21:12:24Z<p><span class="autocomment">Spectral Analysis</span></p>
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<tr><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"><div>Samples of our analysis are shown for two flare events in Figures 2 and 3. Spectrograms (top panels) were useful for determining appropriate power-law energy ranges, which had sufficient non-thermal HXR emission for fitting. Lightcurves (middle panels) were compared to spectral-index (<math>\gamma</math>) progressions (bottom panels) in order to search for SHH events. </div></td><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"><div>Samples of our analysis are shown for two flare events in Figures 2 and 3. Spectrograms (top panels) were useful for determining appropriate power-law energy ranges, which had sufficient non-thermal HXR emission for fitting. Lightcurves (middle panels) were compared to spectral-index (<math>\gamma</math>) progressions (bottom panels) in order to search for SHH events. </div></td></tr>
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<tr><td colspan="2"> </td><td class='diff-marker'>+</td><td style="background: #cfc; color:black; font-size: smaller;"><div><ins style="color: red; font-weight: bold; text-decoration: none;">|+'''The event of September 26, 2003 (12:04-12:09 UT)'''</ins></div></td></tr>
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<tr><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"><div>[[Image:20040919_analysis.jpg|thumb|500px|center|'''Figure 2''': The 2004 September 19 M1.9 flare, displaying distinct SHH spectral evolution. This is clear from the continuously decreasing spectral-index (<math>\gamma</math>) in the bottom panel.]]</div></td><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"><div>[[Image:20040919_analysis.jpg|thumb|500px|center|'''Figure 2''': The 2004 September 19 M1.9 flare, displaying distinct SHH spectral evolution. This is clear from the continuously decreasing spectral-index (<math>\gamma</math>) in the bottom panel.]]</div></td></tr>
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<tr><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"><div>[[Image:20020803_analysis.jpg|thumb|500px|center|'''Figure 3''': The 2002 August 03 X1.0 flare, showing the more typical SHS spectral behavior. The soft-hard-soft signature is seen in the spectral-index (<math>\gamma</math>) time-progression (bottom panel) as the inverse of the lightcurve (middle panel). ]]</div></td><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"><div>[[Image:20020803_analysis.jpg|thumb|500px|center|'''Figure 3''': The 2002 August 03 X1.0 flare, showing the more typical SHS spectral behavior. The soft-hard-soft signature is seen in the spectral-index (<math>\gamma</math>) time-progression (bottom panel) as the inverse of the lightcurve (middle panel). ]]</div></td></tr>
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<tr><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"><div>==Conclusion==</div></td><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"><div>==Conclusion==</div></td></tr>
</table>Schristehttps://sprg.ssl.berkeley.edu/~tohban/wiki/index.php?title=Revisiting_the_SHH_and_SEP_Link&diff=2555&oldid=prevJgrayson at 00:05, 15 February 20102010-02-15T00:05:20Z<p></p>
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<tr><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"><div>|title = Nugget Details</div></td><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"><div>|title = Nugget Details</div></td></tr>
<tr><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"><div>|number = 121</div></td><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"><div>|number = 121</div></td></tr>
<tr><td class='diff-marker'>-</td><td style="background: #ffa; color:black; font-size: smaller;"><div>|first_author = <del class="diffchange diffchange-inline">Jimmy </del>Grayson and</div></td><td class='diff-marker'>+</td><td style="background: #cfc; color:black; font-size: smaller;"><div>|first_author = <ins class="diffchange diffchange-inline">James </ins>Grayson and</div></td></tr>
<tr><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"><div>|second_author = S&auml;m Krucker</div></td><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"><div>|second_author = S&auml;m Krucker</div></td></tr>
<tr><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"><div>|publish_date = 15 February 2010</div></td><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"><div>|publish_date = 15 February 2010</div></td></tr>
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<tr><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"><div>The flare of 2003 November 2 (X8.3) is agreed to have been associated with an SEP event measured at Earth. However, while the previous study found no SHH behavior, our analysis appears to show distinct spectral hardening [http://sprg.ssl.berkeley.edu/~jgrayson/catalog/xclass/2003-11-02T17:25:00QFIT.jpg between 17:20 and 17:30]. </div></td><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"><div>The flare of 2003 November 2 (X8.3) is agreed to have been associated with an SEP event measured at Earth. However, while the previous study found no SHH behavior, our analysis appears to show distinct spectral hardening [http://sprg.ssl.berkeley.edu/~jgrayson/catalog/xclass/2003-11-02T17:25:00QFIT.jpg between 17:20 and 17:30]. </div></td></tr>
<tr><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"><div>It is clear that more investigation into the underlying dynamics of both phenomena is required before a final ruling can be passed on the connection between soft-hard-harder flares and energetic particle events.</div></td><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"><div>It is clear that more investigation into the underlying dynamics of both phenomena is required before a final ruling can be passed on the connection between soft-hard-harder flares and energetic particle events.</div></td></tr>
<tr><td colspan="2"> </td><td class='diff-marker'>+</td><td style="background: #cfc; color:black; font-size: smaller;"><div><ins style="color: red; font-weight: bold; text-decoration: none;"></ins></div></td></tr>
<tr><td colspan="2"> </td><td class='diff-marker'>+</td><td style="background: #cfc; color:black; font-size: smaller;"><div><ins style="color: red; font-weight: bold; text-decoration: none;">==Biographical Note==</ins></div></td></tr>
<tr><td colspan="2"> </td><td class='diff-marker'>+</td><td style="background: #cfc; color:black; font-size: smaller;"><div><ins style="color: red; font-weight: bold; text-decoration: none;"></ins></div></td></tr>
<tr><td colspan="2"> </td><td class='diff-marker'>+</td><td style="background: #cfc; color:black; font-size: smaller;"><div><ins style="color: red; font-weight: bold; text-decoration: none;">James Grayson is an undergraduate physics student at UC Berkeley, and has been working with S&auml;m Krucker at the Space Sciences Lab since January 2009. This article is based on their [http://www.iop.org/EJ/abstract/0004-637X/707/2/1588/ recent publication] in The Astrophysical Journal. Much thanks is owed to Hugh Hudson and the rest of the ''RHESSI'' team for their help in all stages of this work. </ins></div></td></tr>
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<tr><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"><div>[[Category:Nugget]]</div></td><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"><div>[[Category:Nugget]]</div></td></tr>
</table>Jgraysonhttps://sprg.ssl.berkeley.edu/~tohban/wiki/index.php?title=Revisiting_the_SHH_and_SEP_Link&diff=2554&oldid=prevHhudson: /* Introduction */ Linked the Masson-Klein Nugget2010-02-14T11:04:10Z<p><span class="autocomment">Introduction: </span> Linked the Masson-Klein Nugget</p>
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<tr><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"><div>Two previous Nuggets have debated the possibility of a link between solar energetic particle ([http://helios.gsfc.nasa.gov/sep.html SEP]) events and "soft-hard-harder" (SHH) spectral behavior in solar flares. In [http://sprg.ssl.berkeley.edu/~tohban/nuggets/?page=article&article_id=46 "Soft-Hard-Harder"], Sam Krucker and Hugh Hudson discussed five ''RHESSI'' flares that confirmed this relation, but Gerry Share and Allan Tylka later questioned the link when considering five more ''RHESSI'' and ''Yohkoh'' events in [http://sprg.ssl.berkeley.edu/~tohban/wiki/index.php/SEPs_Link_not_Confirmed "SEPs Link not Confirmed"]. </div></td><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"><div>Two previous Nuggets have debated the possibility of a link between solar energetic particle ([http://helios.gsfc.nasa.gov/sep.html SEP]) events and "soft-hard-harder" (SHH) spectral behavior in solar flares. In [http://sprg.ssl.berkeley.edu/~tohban/nuggets/?page=article&article_id=46 "Soft-Hard-Harder"], Sam Krucker and Hugh Hudson discussed five ''RHESSI'' flares that confirmed this relation, but Gerry Share and Allan Tylka later questioned the link when considering five more ''RHESSI'' and ''Yohkoh'' events in [http://sprg.ssl.berkeley.edu/~tohban/wiki/index.php/SEPs_Link_not_Confirmed "SEPs Link not Confirmed"]. </div></td></tr>
<tr><td colspan="2"> </td><td class='diff-marker'>+</td><td style="background: #cfc; color:black; font-size: smaller;"><div><ins style="color: red; font-weight: bold; text-decoration: none;">In addition to these direct discussions, a [[http://sprg.ssl.berkeley.edu/~tohban/wiki/index.php/Solar_Cosmic_Rays_of_the_GLE_on_20_January_2005 Nugget]] by Sophie Masson and Ludwig Klein recently pointed out the complexity of this relationship in a recent remarkable [http://neutronm.bartol.udel.edu/ "ground level event"].</ins></div></td></tr>
<tr><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"></td><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"></td></tr>
<tr><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"><div>This correlation was originally studied by [http://adsabs.harvard.edu/abs/1995ApJ...453..973K Alan Kiplinger], using 10 years of data from the Hard X-ray Burst Spectrometer aboard the [http://en.wikipedia.org/wiki/Solar_Maximum_Mission ''Solar Maximum Mission'']. Kiplinger found that 96% of SEP-producing flares were predicted by non-thermal, hard X-ray (HXR) SHH behavior, suggesting that the two processes are somehow linked. This strong statistical correlation alone is interesting for space-weather prediction applications, but confirming or discrediting the link is also important for motivating further investigation into the actual dynamics that could relate the two phenomena.</div></td><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"><div>This correlation was originally studied by [http://adsabs.harvard.edu/abs/1995ApJ...453..973K Alan Kiplinger], using 10 years of data from the Hard X-ray Burst Spectrometer aboard the [http://en.wikipedia.org/wiki/Solar_Maximum_Mission ''Solar Maximum Mission'']. Kiplinger found that 96% of SEP-producing flares were predicted by non-thermal, hard X-ray (HXR) SHH behavior, suggesting that the two processes are somehow linked. This strong statistical correlation alone is interesting for space-weather prediction applications, but confirming or discrediting the link is also important for motivating further investigation into the actual dynamics that could relate the two phenomena.</div></td></tr>
</table>Hhudsonhttps://sprg.ssl.berkeley.edu/~tohban/wiki/index.php?title=Revisiting_the_SHH_and_SEP_Link&diff=2553&oldid=prevHhudson: added Category:Nugget2010-02-14T10:54:40Z<p>added <a href="/~tohban/wiki/index.php/Category:Nugget" title="Category:Nugget">Category:Nugget</a></p>
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<tr><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"><div>The flare of 2003 November 2 (X8.3) is agreed to have been associated with an SEP event measured at Earth. However, while the previous study found no SHH behavior, our analysis appears to show distinct spectral hardening [http://sprg.ssl.berkeley.edu/~jgrayson/catalog/xclass/2003-11-02T17:25:00QFIT.jpg between 17:20 and 17:30]. </div></td><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"><div>The flare of 2003 November 2 (X8.3) is agreed to have been associated with an SEP event measured at Earth. However, while the previous study found no SHH behavior, our analysis appears to show distinct spectral hardening [http://sprg.ssl.berkeley.edu/~jgrayson/catalog/xclass/2003-11-02T17:25:00QFIT.jpg between 17:20 and 17:30]. </div></td></tr>
<tr><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"><div>It is clear that more investigation into the underlying dynamics of both phenomena is required before a final ruling can be passed on the connection between soft-hard-harder flares and energetic particle events.</div></td><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"><div>It is clear that more investigation into the underlying dynamics of both phenomena is required before a final ruling can be passed on the connection between soft-hard-harder flares and energetic particle events.</div></td></tr>
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<tr><td colspan="2"> </td><td class='diff-marker'>+</td><td style="background: #cfc; color:black; font-size: smaller;"><div><ins style="color: red; font-weight: bold; text-decoration: none;">[[Category:Nugget]]</ins></div></td></tr>
</table>Hhudsonhttps://sprg.ssl.berkeley.edu/~tohban/wiki/index.php?title=Revisiting_the_SHH_and_SEP_Link&diff=2552&oldid=prevHhudson: finished minor edits2010-02-14T10:46:16Z<p>finished minor edits</p>
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<tr><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"><div>==Online Catalog of Events==</div></td><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"><div>==Online Catalog of Events==</div></td></tr>
<tr><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"></td><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"></td></tr>
<tr><td class='diff-marker'>-</td><td style="background: #ffa; color:black; font-size: smaller;"><div>For this study, we initially gathered ''RHESSI'' observations of all 661 X- and M-class flares from 2002 February 12 through the end of Solar Cycle 23 . Flares were then limited to solar locations between West 30<math>^\mathrm{o}</math> and West 90<math>^\mathrm{o}</math>, as these western longitudes are more likely to connect SEPs to Earth by interplanetary magnetic field lines. After eliminating flares without sufficient observational coverage by ''RHESSI'' and those without non-thermal HXR emission above background levels, we were left with 84 flares that were further analyzed for SHH behavior. SEP events were determined by particle flux observations at Earth. The data we used included ''GOES'' proton flux measurements and both proton and electron data from the 3DP instrument aboard ''WIND''. </div></td><td class='diff-marker'>+</td><td style="background: #cfc; color:black; font-size: smaller;"><div>For this study, we initially gathered ''RHESSI'' observations of all 661 X- and M-class flares from 2002 February 12 through the </div></td></tr>
<tr><td colspan="2"> </td><td class='diff-marker'>+</td><td style="background: #cfc; color:black; font-size: smaller;"><div>end of Solar Cycle 23. </div></td></tr>
<tr><td colspan="2"> </td><td class='diff-marker'>+</td><td style="background: #cfc; color:black; font-size: smaller;"><div>Flares were then limited to solar locations between West 30<math>^\mathrm{o}</math> and West 90<math>^\mathrm{o}</math>, as these western longitudes are more likely to connect SEPs to Earth by interplanetary magnetic field lines. After eliminating flares without sufficient observational coverage by ''RHESSI'' and those without non-thermal HXR emission above background levels, we were left with 84 flares that were further analyzed for SHH behavior. SEP events were determined by particle flux observations at Earth. The data we used included ''GOES'' proton flux measurements and both proton and electron data from the 3DP instrument aboard ''WIND''. </div></td></tr>
<tr><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"></td><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"></td></tr>
<tr><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"><div>A full catalog of all our flares, along with SEP event data and SHH analysis is [http://sprg.ssl.berkeley.edu/~jgrayson/ available online]. The online catalog also serves as a quick general reference of all ''RHESSI'' observations of major flares, complete with spectrograms and accompanying ''GOES'' soft X-ray lightcurves. </div></td><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"><div>A full catalog of all our flares, along with SEP event data and SHH analysis is [http://sprg.ssl.berkeley.edu/~jgrayson/ available online]. The online catalog also serves as a quick general reference of all ''RHESSI'' observations of major flares, complete with spectrograms and accompanying ''GOES'' soft X-ray lightcurves. </div></td></tr>
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<tr><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"><div>==Spectral Analysis ==</div></td><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"><div>==Spectral Analysis ==</div></td></tr>
<tr><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"></td><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"></td></tr>
<tr><td class='diff-marker'>-</td><td style="background: #ffa; color:black; font-size: smaller;"><div>In order to search for SHH behavior, we are required to analyze the HXR spectra at multiple time steps during each flaring event. A "harder" spectrum implies that there is a higher ratio of higher-energy emission, and is typical during periods of increased overall flare emission. The majority of events then return to "softer" spectra after emission lessens, and are therefore referred to as soft-hard-soft (SHS) flares. Soft-hard-harder (SHH) events instead show increasing ratios of higher-energy emission, even after overall emission subsides. Since a power-law <del class="diffchange diffchange-inline">spectra </del>is typically <del class="diffchange diffchange-inline">assumed for </del>the HXR <del class="diffchange diffchange-inline">Bremsstrahlung </del>emission <del class="diffchange diffchange-inline">of interest</del>, plotting the spectral-index (<math>\gamma</math>) as a function of time is a good way to visualize spectral hardening and softening during a flaring event; lower <math>\gamma</math> values correspond to a flatter slope of the power-law on a log-log plot, and therefore a harder spectrum (the power-law form is </div></td><td class='diff-marker'>+</td><td style="background: #cfc; color:black; font-size: smaller;"><div>In order to search for SHH behavior, we are required to analyze the HXR spectra at multiple time steps during each flaring event. A "harder" spectrum implies that there is a higher ratio of higher-energy emission, and is typical during periods of increased overall flare emission. The majority of events then return to "softer" spectra after emission lessens, and are therefore referred to as soft-hard-soft (SHS) flares. Soft-hard-harder (SHH) events instead show increasing ratios of higher-energy emission, even after overall emission subsides. </div></td></tr>
<tr><td colspan="2"> </td><td class='diff-marker'>+</td><td style="background: #cfc; color:black; font-size: smaller;"><div>Since a power-law <ins class="diffchange diffchange-inline">spectrum </ins>is typically <ins class="diffchange diffchange-inline">used to describe </ins>the HXR <ins class="diffchange diffchange-inline">bremsstrahlung </ins>emission, plotting the spectral-index (<math>\gamma</math>) as a function of time is a good way to visualize spectral hardening and softening during a flaring event; lower <math>\gamma</math> values correspond to a flatter slope of the power-law on a log-log plot, and therefore a harder spectrum (the power-law form is </div></td></tr>
<tr><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"></td><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"></td></tr>
<tr><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"><div><center><math>I \propto E^{-\gamma}</math>, </center></div></td><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"><div><center><math>I \propto E^{-\gamma}</math>, </center></div></td></tr>
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<td colspan="2" class="diff-lineno">Line 54:</td></tr>
<tr><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"><div><math></math></div></td><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"><div><math></math></div></td></tr>
<tr><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"></td><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"></td></tr>
<tr><td class='diff-marker'>-</td><td style="background: #ffa; color:black; font-size: smaller;"><div>To summarize, we found that two-thirds of flares showing SHH behavior were associated with SEPs, while ''none'' of the flares without SHH behavior had an associated SEP event. Considering the complicated dynamics of the solar wind and magnetic field in interplanetary space, it is reasonable to expect that not all SEPs will be detected at Earth, and so the imperfect correlation of SHH flares with SEP events is not surprising. For a purely statistical analysis, the chi-square value was calculated when assuming the null hypothesis of no SHH/SEP correlation, and was found to be <math>\chi^2=18.7</math>. This corresponds to a rejection of the null hypothesis at more than 99.5% confidence. Therefore, these <del class="diffchange diffchange-inline">are </del>a statistically significant result in favor of the SHH and SEP link proposed by Kiplinger.</div></td><td class='diff-marker'>+</td><td style="background: #cfc; color:black; font-size: smaller;"><div>To summarize, we found that two-thirds of flares showing SHH behavior were associated with SEPs, while ''none'' of the flares without SHH behavior had an associated SEP event. Considering the complicated dynamics of the solar wind and magnetic field in interplanetary space, it is reasonable to expect that not all SEPs will be detected at Earth, and so the imperfect correlation of SHH flares with SEP events is not surprising. For a purely statistical analysis, the chi-square value was calculated when assuming the null hypothesis of no SHH/SEP correlation, and was found to be <math>\chi^2=18.7</math>. This corresponds to a rejection of the null hypothesis at more than 99.5% confidence. </div></td></tr>
<tr><td colspan="2"> </td><td class='diff-marker'>+</td><td style="background: #cfc; color:black; font-size: smaller;"><div>Therefore, these <ins class="diffchange diffchange-inline">new results constitute </ins>a statistically significant result in favor of the SHH and SEP link proposed by Kiplinger.</div></td></tr>
<tr><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"></td><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"></td></tr>
<tr><td class='diff-marker'>-</td><td style="background: #ffa; color:black; font-size: smaller;"><div>Of course, as pointed out in [http://sprg.ssl.berkeley.edu/~tohban/wiki/index.php/SEPs_Link_not_Confirmed SEPs Link not Confirmed], identifying SHH events is not yet <del class="diffchange diffchange-inline">a </del>science. Without a full understanding of what causes SHH spectral behavior, and the possible relation to SEP production, it is impossible to determine what search criteria can be used when looking for SHH events. All similar studies are therefore limited by some inherent subjectivity. For example, while we cannot comment on the ''Yohkoh'' data in [http://sprg.ssl.berkeley.edu/~tohban/wiki/index.php/SEPs_Link_not_Confirmed SEPs Link not Confirmed], one ''RHESSI'' flare used by both studies demonstrates the differing measures of SHH. The 2003 November 2 (X8.3) is agreed to have been associated with an SEP event measured at Earth. However, while the previous study found no SHH behavior, our analysis appears to show distinct spectral hardening [http://sprg.ssl.berkeley.edu/~jgrayson/catalog/xclass/2003-11-02T17:25:00QFIT.jpg between 17:20 and 17:30]. It is clear that more investigation into the underlying dynamics of both phenomena is required before a final ruling can be passed on the connection between soft-hard-harder flares and energetic particle events.</div></td><td class='diff-marker'>+</td><td style="background: #cfc; color:black; font-size: smaller;"><div>Of course, as pointed out in [http://sprg.ssl.berkeley.edu/~tohban/wiki/index.php/SEPs_Link_not_Confirmed SEPs Link not Confirmed], identifying SHH events is not yet <ins class="diffchange diffchange-inline">an exact </ins>science. </div></td></tr>
<tr><td colspan="2"> </td><td class='diff-marker'>+</td><td style="background: #cfc; color:black; font-size: smaller;"><div>Without a full understanding of what causes SHH spectral behavior, and the possible relation to SEP production, it is impossible to determine what search criteria can be used when looking for SHH events. All similar studies are therefore limited by some inherent subjectivity. For example, while we cannot comment on the ''Yohkoh'' data in [http://sprg.ssl.berkeley.edu/~tohban/wiki/index.php/SEPs_Link_not_Confirmed SEPs Link not Confirmed], one ''RHESSI'' flare used by both studies demonstrates the differing measures of SHH. </div></td></tr>
<tr><td colspan="2"> </td><td class='diff-marker'>+</td><td style="background: #cfc; color:black; font-size: smaller;"><div>The <ins class="diffchange diffchange-inline">flare of </ins>2003 November 2 (X8.3) is agreed to have been associated with an SEP event measured at Earth. However, while the previous study found no SHH behavior, our analysis appears to show distinct spectral hardening [http://sprg.ssl.berkeley.edu/~jgrayson/catalog/xclass/2003-11-02T17:25:00QFIT.jpg between 17:20 and 17:30]. </div></td></tr>
<tr><td colspan="2"> </td><td class='diff-marker'>+</td><td style="background: #cfc; color:black; font-size: smaller;"><div>It is clear that more investigation into the underlying dynamics of both phenomena is required before a final ruling can be passed on the connection between soft-hard-harder flares and energetic particle events.</div></td></tr>
</table>Hhudsonhttps://sprg.ssl.berkeley.edu/~tohban/wiki/index.php?title=Revisiting_the_SHH_and_SEP_Link&diff=2551&oldid=prevHhudson: Infobox and edits for Intro2010-02-14T10:36:05Z<p>Infobox and edits for Intro</p>
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<tr><td colspan="2"> </td><td class='diff-marker'>+</td><td style="background: #cfc; color:black; font-size: smaller;"><div><ins style="color: red; font-weight: bold; text-decoration: none;">{{Infobox Nugget</ins></div></td></tr>
<tr><td colspan="2"> </td><td class='diff-marker'>+</td><td style="background: #cfc; color:black; font-size: smaller;"><div><ins style="color: red; font-weight: bold; text-decoration: none;">|name = Nugget</ins></div></td></tr>
<tr><td colspan="2"> </td><td class='diff-marker'>+</td><td style="background: #cfc; color:black; font-size: smaller;"><div><ins style="color: red; font-weight: bold; text-decoration: none;">|title = Nugget Details</ins></div></td></tr>
<tr><td colspan="2"> </td><td class='diff-marker'>+</td><td style="background: #cfc; color:black; font-size: smaller;"><div><ins style="color: red; font-weight: bold; text-decoration: none;">|number = 121</ins></div></td></tr>
<tr><td colspan="2"> </td><td class='diff-marker'>+</td><td style="background: #cfc; color:black; font-size: smaller;"><div><ins style="color: red; font-weight: bold; text-decoration: none;">|first_author = Jimmy Grayson and</ins></div></td></tr>
<tr><td colspan="2"> </td><td class='diff-marker'>+</td><td style="background: #cfc; color:black; font-size: smaller;"><div><ins style="color: red; font-weight: bold; text-decoration: none;">|second_author = S&auml;m Krucker</ins></div></td></tr>
<tr><td colspan="2"> </td><td class='diff-marker'>+</td><td style="background: #cfc; color:black; font-size: smaller;"><div><ins style="color: red; font-weight: bold; text-decoration: none;">|publish_date = 15 February 2010</ins></div></td></tr>
<tr><td colspan="2"> </td><td class='diff-marker'>+</td><td style="background: #cfc; color:black; font-size: smaller;"><div><ins style="color: red; font-weight: bold; text-decoration: none;">|next_nugget = Hard X-ray waiting times</ins></div></td></tr>
<tr><td colspan="2"> </td><td class='diff-marker'>+</td><td style="background: #cfc; color:black; font-size: smaller;"><div><ins style="color: red; font-weight: bold; text-decoration: none;">|previous_nugget = [[Two phases of X-ray emission in a solar eruptive flare]]</ins></div></td></tr>
<tr><td colspan="2"> </td><td class='diff-marker'>+</td><td style="background: #cfc; color:black; font-size: smaller;"><div><ins style="color: red; font-weight: bold; text-decoration: none;">}}</ins></div></td></tr>
<tr><td colspan="2"> </td><td class='diff-marker'>+</td><td style="background: #cfc; color:black; font-size: smaller;"><div><ins style="color: red; font-weight: bold; text-decoration: none;"></ins></div></td></tr>
<tr><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"><div>==Introduction==</div></td><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"><div>==Introduction==</div></td></tr>
<tr><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"></td><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"></td></tr>
<tr><td class='diff-marker'>-</td><td style="background: #ffa; color:black; font-size: smaller;"><div>Two previous Nuggets have debated the possibility of a link between solar energetic particle (SEP) events and "soft-hard-harder" (SHH) spectral behavior in solar flares. In [http://sprg.ssl.berkeley.edu/~tohban/nuggets/?page=article&article_id=46 "Soft-Hard-Harder"], Sam Krucker and Hugh Hudson discussed five ''RHESSI'' flares that confirmed this relation, but Gerry Share and Allan Tylka later questioned the link when considering five more ''RHESSI'' and ''Yohkoh'' events in [http://sprg.ssl.berkeley.edu/~tohban/wiki/index.php/SEPs_Link_not_Confirmed "SEPs Link not Confirmed"]. </div></td><td class='diff-marker'>+</td><td style="background: #cfc; color:black; font-size: smaller;"><div>Two previous Nuggets have debated the possibility of a link between solar energetic particle (<ins class="diffchange diffchange-inline">[http://helios.gsfc.nasa.gov/sep.html </ins>SEP<ins class="diffchange diffchange-inline">]</ins>) events and "soft-hard-harder" (SHH) spectral behavior in solar flares. In [http://sprg.ssl.berkeley.edu/~tohban/nuggets/?page=article&article_id=46 "Soft-Hard-Harder"], Sam Krucker and Hugh Hudson discussed five ''RHESSI'' flares that confirmed this relation, but Gerry Share and Allan Tylka later questioned the link when considering five more ''RHESSI'' and ''Yohkoh'' events in [http://sprg.ssl.berkeley.edu/~tohban/wiki/index.php/SEPs_Link_not_Confirmed "SEPs Link not Confirmed"]. </div></td></tr>
<tr><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"></td><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"></td></tr>
<tr><td class='diff-marker'>-</td><td style="background: #ffa; color:black; font-size: smaller;"><div>This correlation was originally studied by [http://adsabs.harvard.edu/abs/1995ApJ...453..973K Alan Kiplinger], using 10 years of data from the Hard X-ray Burst Spectrometer aboard the ''Solar Maximum Mission''. Kiplinger found that 96% of SEP-producing flares were predicted by non-thermal, hard X-ray (HXR) SHH behavior, suggesting that the two processes are somehow linked. This strong statistical correlation alone is interesting for space-weather prediction applications, but confirming or discrediting the link is also important for motivating further investigation into the actual dynamics that could relate the two phenomena.</div></td><td class='diff-marker'>+</td><td style="background: #cfc; color:black; font-size: smaller;"><div>This correlation was originally studied by [http://adsabs.harvard.edu/abs/1995ApJ...453..973K Alan Kiplinger], using 10 years of data from the Hard X-ray Burst Spectrometer aboard the <ins class="diffchange diffchange-inline">[http://en.wikipedia.org/wiki/Solar_Maximum_Mission </ins>''Solar Maximum Mission''<ins class="diffchange diffchange-inline">]</ins>. Kiplinger found that 96% of SEP-producing flares were predicted by non-thermal, hard X-ray (HXR) SHH behavior, suggesting that the two processes are somehow linked. This strong statistical correlation alone is interesting for space-weather prediction applications, but confirming or discrediting the link is also important for motivating further investigation into the actual dynamics that could relate the two phenomena<ins class="diffchange diffchange-inline">.</ins></div></td></tr>
<tr><td colspan="2"> </td><td class='diff-marker'>+</td><td style="background: #cfc; color:black; font-size: smaller;"><div><ins class="diffchange diffchange-inline">Kiplinger's discovery does not fit neatly into the widely-accepted picture that coronal/interplanetary shock waves, driven ultimately by coronal mass ejections, accelerate these high-energy particles, because the X-ray sources appear in the low corona long after the shock has appeared in the middle corona and gone on into the [http://en.wikipedia.org/wiki/Heliosphere heliosphere]</ins>.</div></td></tr>
<tr><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"></td><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"></td></tr>
<tr><td class='diff-marker'>-</td><td style="background: #ffa; color:black; font-size: smaller;"><div>Here we present the results of [http://www.iop.org/EJ/abstract/0004-637X/707/2/1588/ our recent study] on the subject. Our findings appear to <del class="diffchange diffchange-inline">ratify </del>the statistical correlation between SHH and SEP occurrence, in agreement with Kiplinger's work.</div></td><td class='diff-marker'>+</td><td style="background: #cfc; color:black; font-size: smaller;"><div>Here we present the results of [http://www.iop.org/EJ/abstract/0004-637X/707/2/1588/ our recent study] on the subject. Our findings appear to <ins class="diffchange diffchange-inline">corroborate </ins>the statistical correlation between SHH and SEP occurrence, in agreement with Kiplinger's work.</div></td></tr>
<tr><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"></td><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"></td></tr>
<tr><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"><div>==Online Catalog of Events==</div></td><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"><div>==Online Catalog of Events==</div></td></tr>
</table>Hhudsonhttps://sprg.ssl.berkeley.edu/~tohban/wiki/index.php?title=Revisiting_the_SHH_and_SEP_Link&diff=2544&oldid=prevJgrayson: /* Spectral Analysis */2010-02-10T21:10:13Z<p><span class="autocomment">Spectral Analysis</span></p>
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<tr><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"><div>==Spectral Analysis ==</div></td><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"><div>==Spectral Analysis ==</div></td></tr>
<tr><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"></td><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"></td></tr>
<tr><td class='diff-marker'>-</td><td style="background: #ffa; color:black; font-size: smaller;"><div>In order to search for SHH behavior, we are required to analyze the HXR spectra at multiple time steps during each flaring event. A "harder" spectrum implies that there is a higher ratio of higher-energy emission, and is typical during periods of increased flare emission. The majority of events then return to "softer" spectra after emission lessens, and are therefore referred to as soft-hard-soft (SHS) flares. Soft-hard-harder (SHH) events instead show increasing ratios of higher-energy emission, even after emission subsides. Since a power-law spectra is typically assumed for the HXR Bremsstrahlung emission of interest, plotting the spectral-index (<math>\gamma</math>) as a function of time is a good way to visualize spectral hardening and softening during a flaring event; lower <math>\gamma</math> values correspond to a flatter slope of the power-law on a log-log plot, and therefore a harder spectrum (the power-law form is </div></td><td class='diff-marker'>+</td><td style="background: #cfc; color:black; font-size: smaller;"><div>In order to search for SHH behavior, we are required to analyze the HXR spectra at multiple time steps during each flaring event. A "harder" spectrum implies that there is a higher ratio of higher-energy emission, and is typical during periods of increased <ins class="diffchange diffchange-inline">overall </ins>flare emission. The majority of events then return to "softer" spectra after emission lessens, and are therefore referred to as soft-hard-soft (SHS) flares. Soft-hard-harder (SHH) events instead show increasing ratios of higher-energy emission, even after <ins class="diffchange diffchange-inline">overall </ins>emission subsides. Since a power-law spectra is typically assumed for the HXR Bremsstrahlung emission of interest, plotting the spectral-index (<math>\gamma</math>) as a function of time is a good way to visualize spectral hardening and softening during a flaring event; lower <math>\gamma</math> values correspond to a flatter slope of the power-law on a log-log plot, and therefore a harder spectrum (the power-law form is </div></td></tr>
<tr><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"></td><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"></td></tr>
<tr><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"><div><center><math>I \propto E^{-\gamma}</math>, </center></div></td><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"><div><center><math>I \propto E^{-\gamma}</math>, </center></div></td></tr>
</table>Jgraysonhttps://sprg.ssl.berkeley.edu/~tohban/wiki/index.php?title=Revisiting_the_SHH_and_SEP_Link&diff=2537&oldid=prevJgrayson: /* Conclusion */2010-01-31T06:42:00Z<p><span class="autocomment">Conclusion</span></p>
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<tr><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"><div>To summarize, we found that two-thirds of flares showing SHH behavior were associated with SEPs, while ''none'' of the flares without SHH behavior had an associated SEP event. Considering the complicated dynamics of the solar wind and magnetic field in interplanetary space, it is reasonable to expect that not all SEPs will be detected at Earth, and so the imperfect correlation of SHH flares with SEP events is not surprising. For a purely statistical analysis, the chi-square value was calculated when assuming the null hypothesis of no SHH/SEP correlation, and was found to be <math>\chi^2=18.7</math>. This corresponds to a rejection of the null hypothesis at more than 99.5% confidence. Therefore, these are a statistically significant result in favor of the SHH and SEP link proposed by Kiplinger.</div></td><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"><div>To summarize, we found that two-thirds of flares showing SHH behavior were associated with SEPs, while ''none'' of the flares without SHH behavior had an associated SEP event. Considering the complicated dynamics of the solar wind and magnetic field in interplanetary space, it is reasonable to expect that not all SEPs will be detected at Earth, and so the imperfect correlation of SHH flares with SEP events is not surprising. For a purely statistical analysis, the chi-square value was calculated when assuming the null hypothesis of no SHH/SEP correlation, and was found to be <math>\chi^2=18.7</math>. This corresponds to a rejection of the null hypothesis at more than 99.5% confidence. Therefore, these are a statistically significant result in favor of the SHH and SEP link proposed by Kiplinger.</div></td></tr>
<tr><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"></td><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"></td></tr>
<tr><td class='diff-marker'>-</td><td style="background: #ffa; color:black; font-size: smaller;"><div>Of course, as pointed out in [http://sprg.ssl.berkeley.edu/~tohban/wiki/index.php/SEPs_Link_not_Confirmed SEPs Link not Confirmed], identifying SHH events is not yet a science. Without a full understanding of what causes SHH spectral behavior, and the possible relation to SEP production, it is impossible to determine what search criteria can be used when looking for SHH events. All similar studies are therefore limited by some inherent subjectivity. <del class="diffchange diffchange-inline">However</del>, while we cannot comment on the ''Yohkoh''</div></td><td class='diff-marker'>+</td><td style="background: #cfc; color:black; font-size: smaller;"><div>Of course, as pointed out in [http://sprg.ssl.berkeley.edu/~tohban/wiki/index.php/SEPs_Link_not_Confirmed SEPs Link not Confirmed], identifying SHH events is not yet a science. Without a full understanding of what causes SHH spectral behavior, and the possible relation to SEP production, it is impossible to determine what search criteria can be used when looking for SHH events. All similar studies are therefore limited by some inherent subjectivity. <ins class="diffchange diffchange-inline">For example</ins>, while we cannot comment on the ''Yohkoh'' <ins class="diffchange diffchange-inline">data in [http://sprg.ssl.berkeley.edu/~tohban/wiki/index.php/SEPs_Link_not_Confirmed SEPs Link not Confirmed], one ''RHESSI'' flare used by both studies demonstrates the differing measures of SHH. The 2003 November 2 (X8.3) is agreed to have been associated with an SEP event measured at Earth. However, while the previous study found no SHH behavior, our analysis appears to show distinct spectral hardening [http://sprg.ssl.berkeley.edu/~jgrayson/catalog/xclass/2003-11-02T17:25:00QFIT.jpg between 17:20 and 17:30]. It is clear that more investigation into the underlying dynamics of both phenomena is required before a final ruling can be passed on the connection between soft-hard-harder flares and energetic particle events.</ins></div></td></tr>
</table>Jgrayson