tag:blogger.com,1999:blog-2220966763638300672.post3713797811679109464..comments2023-07-29T05:11:23.558-04:00Comments on Climate Observations: A Look At The Individual Proxies Used In Kaufman et al (2009)Bob Tisdalehttp://www.blogger.com/profile/15462377647970214137noreply@blogger.comBlogger9125tag:blogger.com,1999:blog-2220966763638300672.post-46290708126583898342009-12-20T17:22:54.291-05:002009-12-20T17:22:54.291-05:00Anonymous: "I just removed the Yamal Series a...Anonymous: "I just removed the Yamal Series and averaged. The early part of the chart almost equals the latter (late 20th century) part. ie what's the concern."<br /><br /><br />I suppose if you just say all we have done is come back to where we were 2000 years ago, you could say that. But the fact that we essentially recouped the temperature drop that occurred over the past 1900 years in a short 100 year period should be raise some sort of flag shouldn't it?<br /><br />It not the fact that we may have raised temperatures back to where they were in the distant past, but the rapid rate in which the temperatures have increased is of concern.<br /><br />I also suggest plotting out the same 23 proxy data (not just the averages in column Y) by using a running 100-year average period for all the proxy data and see what the graph looks like, starting with the year 95.<br /><br />The noted rapid rate of increase in proxy temperatures during the past 100 years should be fairly obvious.<br /><br />Dennis H.Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-2220966763638300672.post-75536342294684392612009-12-18T16:21:19.675-05:002009-12-18T16:21:19.675-05:00NZ Willy: Correct me if I'm wrong, but wasn...NZ Willy: Correct me if I'm wrong, but wasn't the Briffa reconstruction you're referring to a composite of multiple Northern Hemisphere proxies? The three Briffa datasets shown above are individuals. And two of the three Briffa datasets included do show declines after 1945.Bob Tisdalehttps://www.blogger.com/profile/15462377647970214137noreply@blogger.comtag:blogger.com,1999:blog-2220966763638300672.post-43675840461281842982009-12-18T15:25:10.791-05:002009-12-18T15:25:10.791-05:00Are these Briffa series the ones which have actual...Are these Briffa series the ones which have actual temperatures spliced on at 1960? If so, you can lop off the post-1960 Briffa data -- indeed, you would need to.NZ Willynoreply@blogger.comtag:blogger.com,1999:blog-2220966763638300672.post-16729549977139129062009-12-18T04:50:17.751-05:002009-12-18T04:50:17.751-05:00Anonymous: You asked, “Are you fricking kidding ...Anonymous: You asked, “Are you fricking kidding me!!<br />Surely, Kaufman did not just average the proxies together to get the BBC graph?”<br /><br />Again, my opinion in based on the fact that there are many other long-term proxies available but they were not included in this study. Lindqvist also published a collection of two-millennia proxies in 2009.<br />http://www3.interscience.wiley.com/cgi-bin/fulltext/122225084/PDFSTART<br /><br />Looking at Lindqvist’s Table 1, there are 37 Proxies North of 60N that cover the vast majority of the two-millennia time span. Why didn’t Kaufman include the others? And if Kaufman et al was a study of two millennia, why didn’t they limit the proxies to that period? In other words, many of the Kaufman proxies do not begin until mid-to-late in the first millennium. Why are they included? <br /><br />Again, Kaufman appears to include a grouping of proxies that were hand selected to provide a desired outcome, which was the graph of the long-term decline in temperatures, followed by a steep rise in recent decades.<br /><br />The Linqvist data is here:<br />ftp://ftp.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/ljungqvist2009/ljungqvist2009recons.txtBob Tisdalehttps://www.blogger.com/profile/15462377647970214137noreply@blogger.comtag:blogger.com,1999:blog-2220966763638300672.post-38621027143456949302009-12-17T23:42:14.600-05:002009-12-17T23:42:14.600-05:00Bob
Are you fricking kidding me!!
Surely, Kaufman...Bob<br /><br />Are you fricking kidding me!!<br />Surely, Kaufman did not just average the proxies together to get the BBC graph?<br /><br />I just removed the Yamal Series and averaged. The early part of the chart almost equals the latter (late 20th century) part. ie what's the concern.<br /><br />It can't be that simple.Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-2220966763638300672.post-14623484434818173762009-12-17T17:36:55.708-05:002009-12-17T17:36:55.708-05:00Anonymous 12:36PM: You wrote, “A few questions and...Anonymous 12:36PM: You wrote, “A few questions and suggestions for a second part on this subject.”<br /><br />I have no plans for a second part. I really have a very limited interest in paleoclimatological studies.<br /><br />You asked, “Do you have any idea why the scale is so different in your avarages (several°C) than in the press release(less than 1°C)?”<br /><br />The data from the NOAA Paleoclimatological Program website is standardized. The graph from the BBC is not.<br /><br />You wrote, “This one of the best paleoclimate studies publicated so far for the Arctic, as it is a synthesis of 23 multi-proxy studies.”<br /><br />Personally, to the skeptical side of me, it appears to be a grouping of proxies that were hand selected to provide a desired outcome, which was the graph of the long-term decline in temperatures, followed by a steep rise in recent decades. My opinion in based on the fact that there are many other long-term proxies available but they were not included in this study. <br /><br />You wrote, “It will be great to average the proxies from the same region(Alaska, Canadian Archipielago, Greenland, Scandinavia, Siberia).”<br /><br />The link to the spreadsheet is here (or above):<br />ftp://ftp.ncdc.noaa.gov/pub/data/paleo/reconstructions/arctic/kaufman2009arctic.xls<br /><br />RegardsBob Tisdalehttps://www.blogger.com/profile/15462377647970214137noreply@blogger.comtag:blogger.com,1999:blog-2220966763638300672.post-88341560663828516502009-12-17T12:36:24.670-05:002009-12-17T12:36:24.670-05:00Thanks for your (as usual) beautiful graphs:
The ...Thanks for your (as usual) beautiful graphs: <br />The average give a general idea for the periferic Arctic Region(periferic because none of this data comes from the Arctic Ocean itself, but from the nearby land), but to have a complete undestanding of then trends one must descend to the regional-to-local level.<br /><br />A few questions and suggestions for a second part on this subject:<br /><br />1)Do you have any idea why the scale is so different in your avarages (several°C) than in the press release(less than 1°C)?<br /><br />2)This one of the best paleoclimate studies publicated so far for the Arctic, as it is a synthesis of 23 multi-proxy studies.<br /><br />It will be great to average the proxies from the same region(Alaska, Canadian Archipielago, Greenland, Scandinavia, Siberia).<br /><br />3)Then compare the proxy data with the GISSTEMP station data.<br /><br />A FINAL REMARK: as one improve the resolution and "zoom" to regional-to-local level, weather and climate variability greatly increases.<br /><br />So isn't surprising that there are notable variations between the different places. Some warm and other cool at the same time, so while the improved resolution permits a better analysis, it may be misleading if one forgets the Big Picture(all-Arctic): some places may have been warmer in the past than now, but this is expected as the inter-regional variation increases together with the spatial resolution (for example between Alaska and Siberia).<br /><br />One of the characteristics of contemporary Global Warming, specially since the 1980s, is its WIDESPREAD nature, with big warm anomalies covering entire Continents or Ocean Basins(in this case, the whole Arctic) for entire seasons of the year (in the Arctic, specially in Fall and Winter).<br /><br />This greatly contrast with previous climate anomalies, when some areas warmed and other cooled.Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-2220966763638300672.post-10039906970278398482009-12-17T10:55:39.258-05:002009-12-17T10:55:39.258-05:00AMac: You asked, "So my question is how you ...AMac: You asked, "So my question is how you weight these no-post-1800-data proxies in calculating the average, equally-weighted signal. Is it simply a matter of normalizing each proxy such that the Y-axis is SDs, and then summing for each year or decade for which the proxy is available?"<br /><br />If a cell has no data, EXCEL excludes it in its averages.Bob Tisdalehttps://www.blogger.com/profile/15462377647970214137noreply@blogger.comtag:blogger.com,1999:blog-2220966763638300672.post-53137299274040595672009-12-17T09:48:44.838-05:002009-12-17T09:48:44.838-05:00Bob,
Very informative post, thanks for the link a...Bob,<br /><br />Very informative post, thanks for the link at Climate Audit. The standardized graphical views of the Kaufman figure, the summed proxies, and the individual records is helpful.<br /><br />Re: the Tiljander (Lake Korttajarvi, Finland) varve proxy (and certain other lakebed sediment proxies), Kaufman's correction truncates the series at 1800, prior to the start of the instrumented record. This was the right thing to do, as Tiljander noted that the climate signal is accompanied and then surpassed by (spurious) human-activity signals, starting in ~1720. (This action was in addition to flipping the X-Ray Density interpretation from the upside-down Mann orientation to that suggested by Tiljander.)<br /><br />So my question is how you weight these no-post-1800-data proxies in calculating the average, equally-weighted signal. Is it simply a matter of normalizing each proxy such that the Y-axis is SDs, and then summing for each year or decade for which the proxy is available?<br /><br />IIRC, Steve McIntyre once noted in passing that Tiljander's data record contains an anomolous set of readings for one varve, for 1326 I believe. At <a href="ftp://ftp.ncdc.noaa.gov/pub/data/paleo/paleolimnology/europe/finland/korttajarvi2003.txt" rel="nofollow">NOAA's FTP site for Tiljander et al (2003)</a>, XRD is as follows:<br />1324 - 94.3<br />1325 - 84.3<br />1326 - 172.6<br />1327 - 120.0<br />1328 - 100.7<br /><br />Values for Lightsum, Darksum, and Thickness (used by Mann et al 2008 but not by Kaufman et al 2009) for 1326 are much farther from the neighboring years. Mann et al <i>might</i> have adjusted 1326 values (I'm traveling and can't check the zipped files <a href="http://www.ncdc.noaa.gov/paleo/pubs/mann2008/mann2008.html" rel="nofollow">here</a>). I'll follow up later.<br /><br />A work-in-progress compilation of Tiljander-related resources is <a href="http://amac1.blogspot.com/2009/11/primary-links-mann-08-and-korttajarvi.html" rel="nofollow">here</a>.AMachttps://www.blogger.com/profile/08872008617279528583noreply@blogger.com