date: Fri Jun 3 15:15:47 2005 from: Phil Jones subject: Re: 1816 tropical SSTs to: "Rob Wilson" Rob, I seem to have gotten the coral paper anyway ! I'll have a look at it as I'm away next week. When I was including coral in the 1998 paper it was length we were looking for rather than numbers. There are more now. Correlations with SST can be difficult because of the quality of the SST data for some regions for some periods. I tended to go for a reasonable size box where the coral's from, to avoid basing it on a single box. The GBR stuff from Janice Lough was the best, but then that was several corals anyway. We had trouble getting the Galapagos to correlate. Cheers Phil At 09:22 03/06/2005, you wrote: Morning Phil, no the Nature paper is a TR based NH extra-tropical temperature reconstruction that I wrote with Rosanne D'Arrigo. Essentially a substantial update (1250 years in length) to the original Jacoby and D'Arrigo work. The coral paper is a different beast. I am leaning towards JGR for submission as I don't think it has the restrictive word length of GRL. I can send you the last draft of the coral paper if you like, although I hope to tighten it in the next week or so. For the coral reconstruction, I did not include the New Caledonia data. I set up a fairly stringent screening procedure for the coral data - i.e. only those series that correlated significantly with local annual SSTs using both unfiltered and 1st differenced time-series were used for later analysis. The new Caledonia data did not pass this test. This is, in fact, a problem with many of the coral data-sets - the long term trends in these data might be related to salinity changes rather than SST. However, due to strong linear trends, there is often a reasonable correlation with local SST using unfiltered series, which is purely an artefact of trend. Hence my use of 1st difference transforms to identify a 'pure' temperature signal. The new Caledonia data did not correlate significant with local SSTs at these high frequencies - hence, using my empirical approach, I could not rationalise the record to be a true temperature proxy. Although a strict interpretation of the new Caledonia O18 record as a temperature proxy would indicate cooler conditions around the 1810-1820 period, I do not think such an interpretation is entirely correct. Also, through this period, the lowest index value is 1814, not 1816. 1885 is an inferred cool year which could tie in nicely with Krakatoa however. It is also interesting to note that many of the coral records utilised by Mike Mann also failed my screening procedure. The attached figure shows normalised series of the 5 coral records that go back to 1801 in my 'SST sensitive' data-set. The y-axis has been inverted as the series are negatively correlated to SSTs. Only one record (MAL = Malindi: western Indian Ocean - Julia Cole) shows an inferred cool year in 1816. As I state in the paper - lots of potential for corals, but there is simply not enough data prior to 1850 to derive particularly robust reconstructions. just say if you want a copy of the paper hope this helps best regards Rob ----- Original Message ----- From: [1]Phil Jones To: [2]Rob Wilson Sent: Thursday, June 02, 2005 3:48 PM Subject: Re: 1816 tropical SSTs Rob, Nice diagram ! Is this in the Nature submission you were talking to Keith about this morning. I'd put more faith in the few corals at this time the ships. I think corals have juvenile problems like trees. Is any of Crowley's corals from the New Caledonia region in the coral set. Tom makes a big thing of their cooling in the 1810s. Cheers Phil At 15:11 02/06/2005, you wrote: Dear Michael, Last week, from a BBC Timewatch documentary, I was very interested to learn about your research on historical temperatures in the year after the Tambora eruption. Phil Jones sent me your e-mail address so I could contact you. I am working with Keith Briffa and have been using coral isotopic records to reconstruct annual tropical SSTs for the last few centuries. A paper will be submitted on this work in the next few weeks. One of the observations that our reconstruction shows is that tropical SSTs were not particularly anomalous around 1816 - see attached figure. We are wondering if your results agree or disagree with our observation. Unfortunately, there are only a few coral records that go back to the early 19th century, so the fact that we do not identify cool SSTs in 1816 might reflect the spatial bias in our coral record network. However, teak tree-ring chronologies from Indonesia also do not show anomalous growth departures for this period. Do you per chance have any spatial maps of SSTs for this year? I would also be interested in any articles you have written (or that are in preparation) with regards to 1816. I hope you can help best regards Rob ----------------------------------------------------------------------- Dr. Rob Wilson Honorary Research Fellow School of GeoSciences, Grant Institute, Edinburgh University, West Mains Road, Edinburgh EH9 3JW, Scotland, U.K. Tel: 0131 620 1141 Publication PDFs: [3]http://www.robdendro.pwp.blueyonder.co.uk/publications.html ".....I have wondered about trees. They are sensitive to light, to moisture, to wind, to pressure. Sensitivity implies sensation. Might a man feel into the soul of a tree for these sensations? If a tree were capable of awareness, this faculty might prove useful. " "The Miracle Workers" by Jack Vance ----------------------------------------------------------------------- Prof. Phil Jones Climatic Research Unit Telephone +44 (0) 1603 592090 School of Environmental Sciences Fax +44 (0) 1603 507784 University of East Anglia Norwich Email p.jones@uea.ac.uk NR4 7TJ UK ---------------------------------------------------------------------------- Prof. Phil Jones Climatic Research Unit Telephone +44 (0) 1603 592090 School of Environmental Sciences Fax +44 (0) 1603 507784 University of East Anglia Norwich Email p.jones@uea.ac.uk NR4 7TJ UK ----------------------------------------------------------------------------