{"id":4839,"date":"2009-05-11T11:15:45","date_gmt":"2009-05-11T17:15:45","guid":{"rendered":"http:\/\/rankexploits.com\/musings\/?p=4839"},"modified":"2009-05-11T19:49:34","modified_gmt":"2009-05-12T01:49:34","slug":"how-would-figure-95a-from-the-ar4-look-today","status":"publish","type":"post","link":"https:\/\/rankexploits.com\/musings\/2009\/how-would-figure-95a-from-the-ar4-look-today\/","title":{"rendered":"How would Figure 9.5a from the AR4 look today?"},"content":{"rendered":"

While visiting Climate Audit<\/a> I clicked a link to web page that reminded me that Chapter 9 of the WG1 contribution to the IPCC AR4 used the 1901-1950 baseline to illustrate how well models hindcast the 20th century:

\"Figure<\/a>
Figure 1: Figure 9.5a as it appeared in the AR4.<\/figcaption><\/figure><\/p>\n

The AR4 was published in 2007, so data end with the annual average data for 2005. Note the red is the multi-model mean; the yellow are the individual runs. Black is HadCrut. Before proceeding, also note that all projected temperature anomalies above 1C are cut off on that graph. Those glancing quickly might infer the 1998 El Nino was near the maximum temperature anomaly projected by the collection of runs.<\/p>\n

My first thought when I saw this was “Hmmm… I wonder how that graphs would look if we added data from 2006 onward?” So, naturally I did that. Voila:<\/p>\n

\"Figure<\/a>
Figure 2: Updated Figure 9.5<\/figcaption><\/figure>\n

I made a few changes to Figure 9.5, including: I<\/p>\n

    \n
  1. Cut out data before 1950 to permit better focus on the comparison outside the baseline period. (The baseline method forces agreement of the average temperature anomaly during the baseline period.)<\/li>\n
  2. Used different colors for each run and including \u00c2\u00b195% bounds for all temperature anomalies in all runs, computed assuming anomalies are normally distributed.<\/li>\n
  3. Adjusted the vertical axis to display the full range of model runs include anomalies greater than 1C. Notice that the 1998 El Nino no longer seems particularly high compared to the model runs? Interestingly, if you click to see the larger graph<\/a> you’ll see that GISStemp barely pierced the multi-model mean projection during that “super El Nino”. <\/li>\n
  4. Added 12 month averages through the month ending March 2009. I think this shifts my graph 11 months relative to the graph in the AR4, because I think the AR4 ‘2005’ corresponds to Jan 1, 2005-Dec 2005. I’ve indicated where data for the 12 months from Jan 2005- Dec 2005 with a vertical blue line.<\/li>\n
  5. Included a few extra runs available at The Climate Explorer and excluded the runs with no projections based on the A1B scenario. I did not screen for “excess model drift”; the caption for figure 9.5 indicates the authors of the AR4 screened for this. <\/li>\n<\/ol>\n

    I’m not sure anyone can conclude much from this graph, but I find it interesting to periodically update the figures periodically to see how things are going. Right now: The using this baseline model projections lie above the observations. <\/p>\n","protected":false},"excerpt":{"rendered":"

    While visiting Climate Audit I clicked a link to web page that reminded me that Chapter 9 of the WG1 contribution to the IPCC AR4 used the 1901-1950 baseline to illustrate how well models hindcast the 20th century: The AR4 was published in 2007, so data end with the annual average data for 2005. Note … Continue reading How would Figure 9.5a from the AR4 look today?<\/span> →<\/span><\/a><\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[15],"tags":[21,34],"class_list":["post-4839","post","type-post","status-publish","format-standard","hentry","category-data-comparisons","tag-gmst","tag-ipcc"],"_links":{"self":[{"href":"https:\/\/rankexploits.com\/musings\/wp-json\/wp\/v2\/posts\/4839","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/rankexploits.com\/musings\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/rankexploits.com\/musings\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/rankexploits.com\/musings\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/rankexploits.com\/musings\/wp-json\/wp\/v2\/comments?post=4839"}],"version-history":[{"count":0,"href":"https:\/\/rankexploits.com\/musings\/wp-json\/wp\/v2\/posts\/4839\/revisions"}],"wp:attachment":[{"href":"https:\/\/rankexploits.com\/musings\/wp-json\/wp\/v2\/media?parent=4839"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/rankexploits.com\/musings\/wp-json\/wp\/v2\/categories?post=4839"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/rankexploits.com\/musings\/wp-json\/wp\/v2\/tags?post=4839"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}