Climate Audit

Back from Arizona and Colorado, where I visited family and friends in Phoenix and Colorado Springs. I didn’t spend much time on the internet. I had an opportunity to read Anthony’s interesting new posts on more stations. Each new station seems to yield an interesting story. It is disquieting that the USHCN site with the greatest relative temperature increase (University of Arizona – Tucson) is both located in a parking lot and operated by a university science department (Malcolm Hughes of MBH is also at the University of Arizona). I traveled through Phoenix airport (which is a GHCN, GISS, Parker and probably CRU site) and, while I did not have a chance to locate the weather station, it will not surprise readers that Phoenix Sky Harbor airport is a big urbanized airport. We went to Sedona on a day trip and the tourist brochures said that the Sinagua Indians abandoned the area in the 1400s – something that might be related to climate and which might be worth following up on another occasion.

I took the occasion of my visit to Colorado to specifically visit some bristlecones in the Mt Almagre area west of Colorado Springs (thanks to CA reader Pete Holzmann), together with our wives and my sister. I’ll write a few posts about bristlecones over the next couple of weeks, including photographs and a really neat Google Earth itinerary of our trip up Almagre, including a discussion of the Starbucks hypothesis (whether a dendrochronologist can have a latte in the morning and still carry out a sampling program). We reached a little higher elevation than the Sheep Mountain CA bristlecones (which are about one degree further south) and were still below treeline. There are a number of ways to reach treeline in different parts of Colorado, one of the more interesting being the Pikes Peak climb, for which practice runs were taking place during our visit.

We also spent a couple of days in Breckenridge, a ski resort at 10 000 feet about 2 hours west of Colorado Springs. We had an interesting drive across the continental divide and through South Park, so I had an opportunity to see quite a few panoramas showing high-altitude treelines. Upper border treelines are supposedly required in order to obtain temperature proxies from ring widths, so it was interesting to see so many treeline vistas.

Having stood on a hill at 11 400 feet ( a little higher than Graybill’s Sheep Mt samples) which was below local treeline of 11,800-11,900 feet, it made me wonder a little about why the Sheep Mountain CA treeline is so low. Also the competition between trees at Colorado treeline appears to be different than in California: in California, bristlecones compete with big sagebrush, while in Colorado, both Engelmann spruce and bristlecones occur at high altitudes and presumably compete. It would be interesting to know what governs the competition between them and why the competition is different than California. It would be nice to see maps describing the competition, but I’ve not seen any, despite the importance placed on this data for climate reconstructions. High-altitude bristlecone sites actually appear to be more prevalent in Colorado than in California and it is more than a little disappointing that no high-altitude collections in Colorado have been updated in over 15 years.

So there are a number of things to talk about. Today, I want to do a brief survey, scoping high-altitude sites in Colorado and elsewhere. I’ll also make some comments on Pike’s Peak (which is also to the west of Colorado Springs, just to the north of Almagre), which was the site of the annual Pike’s Peak Hill Climb on July 21. Continue reading →