<div style="margin: 12px 0px; font-family: arial; color: #333333; background: #ffffff; border: solid 4px #e5e5e5; width: 100%; clear: left;"><div class="CM_CTB_Content_Wrap" style="margin: 0px; padding: 0px;background-color: #ffffff;"><div style="border-bottom: solid 1px #dcdcdc; white-space: nowrap; margin-bottom: 8px; background-color: #eeeeee ;background-image: url(http://clipmarks.com/images/source-bg.gif); background-repeat: repeat-x; height: 24px; line-height: 24px; vertical-align: middle; padding-bottom: 4px; color: #666666; font-size: 10px;" ><a href="http://clipmarks.com/clip-to-blog/" title="see clips that are hot right now"><img src="http://content.clipmarks.com/blog_embed/9262f02f-97ae-4a0b-b1e1-18e9ca8a3fde/78E91500-1D0E-450B-A57A-DD5A1745BC7B/" alt="" width="19" height="19" border="0" style="vertical-align: middle; margin: 0px 4px; display: inline; border: none; float:none;" /></a>clipped from <a title="http://www.agu.org/pubs/crossref/2009/2009GL037242.shtml" href="http://www.agu.org/pubs/crossref/2009/2009GL037242.shtml" style="font-size: 11px;">www.agu.org</a></div><blockquote style="text-align: left; padding: 0px 8px; margin: 4px 0px 8px 0px; background: transparent; border: none;" cite="http://www.agu.org/pubs/crossref/2009/2009GL037242.shtml"><P>An innovative technique utilizes a tree‐ring marker to investigate long‐term changes in the frequency of cool summers in Interior North America (INA), a region that currently suffers important gaps in knowledge concerning annual to secular temperature changes. Using multivariate adaptive regression splines (MARS), we established a threshold for the formation of climatically‐induced light rings recorded in <I>Pinus banksiana</I> trees from INA. Then, we used the MARS model to reconstruct negative departures in summer maximum temperatures (April–September) from 1717 to 2007. The estimates explain 45% of the variance in instrumental temperature data. The reconstruction indicates the presence of significant multidecadal changes in the frequency of cool summers, with maximums in 1780, 1900 and 1960 and minimums in 1740, 1860, 1920 and 2000. No evidence of secular changes was found. </P></blockquote><div style="height: 2px; font-size: 2px; background: #dcdcdc; border-bottom: solid 1px #f5f5f5; margin: 2px 4px;"></div><blockquote style="text-align: left; padding: 0px 8px; margin: 4px 0px 8px 0px; background: transparent; border: none;" cite="http://www.agu.org/pubs/crossref/2009/2009GL037242.shtml"><I>Geophys. Res. Lett.</I></blockquote><div style="height: 2px; font-size: 2px; background: #dcdcdc; border-bottom: solid 1px #f5f5f5; margin: 2px 4px;"></div><blockquote style="text-align: left; padding: 0px 8px; margin: 4px 0px 8px 0px; background: transparent; border: none;" cite="http://www.agu.org/pubs/crossref/2009/2009GL037242.shtml"><SPAN class="bold"><B>Citation: </B></SPAN><SPAN id="authors"><SPAN id="first-author">Girardin, M. P.</SPAN></SPAN></blockquote><div style="height: 2px; font-size: 2px; background: #dcdcdc; border-bottom: solid 1px #f5f5f5; margin: 2px 4px;"></div><blockquote style="text-align: left; padding: 0px 8px; margin: 4px 0px 8px 0px; background: transparent; border: none;" cite="http://www.agu.org/pubs/crossref/2009/2009GL037242.shtml"><SPAN id="journal"><SPAN class="ital"><I>Geophys. Res. Lett.</I></SPAN></SPAN>, <SPAN id="volume"><SPAN class="ital">36</SPAN></SPAN>, L07705, doi:10.1029/2009GL037242</blockquote></div><div style="margin: 0px 6px 6px 4px;"><table style="font-size: 11px;border-spacing: 0px;padding: 0px;" cellpadding="0" cellspacing="0" width="100%"><tr><td style="background:transparent;border-width:0px;padding:0px;">&nbsp;</td><td align="right" style="background:transparent;border-width:0px;padding:0px;width:107px" width="107"><a href="http://clipmarks.com/share/78E91500-1D0E-450B-A57A-DD5A1745BC7B/blog/" title="blog or email this clip"><img src="http://content6.clipmarks.com/images/c2b-foot.png" border="0" alt="blog it" width="107" height="17" style="border-width:0px;padding:0px;margin:0px;" /></a></td></tr></table></div></div>

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