cc: Tom Crowley date: Thu, 6 Jun 2002 14:59:26 -0400 from: Gabi Hegerl subject: Tom and my reconstruction to: Phil Jones , t.osborn@uea.ac.uk Hi Phil and Tim, Here comes the information on Tom and my reconstruction. I can easily redo it for seasonal or growing season means, I'd actually be happy to and check if that is better. I count on your discretion since I have not yet fully published this anywhere, but I am working at it! proxycompclg1.2.as is the CLH reconstruction as ascii timeseries (1: year, 2: reconstruction 3: NH 30-90N mean annual instrumental for comparison). reconstructionsnewphil.as is an ascii file that explains how this was done and gives for example the weights and stations used (it has a longer list, but those I wound up using are marked by **, Mongolia treerings got kicked out despite ok correlations because of the low- resolution and Tom had some other worries about them) and some correlations recordclh.psc is a ps file showing the timeseries compared to instrumental and Tom's old reconstruction. recordsused.ps is a plot of the timeseries used. I'll also attach two files, cl6.as with the proxy timeseries as used, and cl6.readme with the headers (matlab cannot easily digest a mix of ascii and numbers). On this, I count also on your discretion since I am not sure exactly what Tom has as agreements with the people, we can talk about all this in Thera! Hope this helps! See you in Thera, Phil! Greetings Gabi Gabi, Can you send the series to me and Tim Osborn (t.osborn@uea.ac.uk)? No rush as we're both away for much of the next 3-5 weeks. Also can you send the weights and the original series as well. Maybe also send the series you didn't use when correlations were small. I agree that combining a simple way maybe better than MLR but we need to compare a range of methods. If there isn't time we can discuss all this on Thera. Cheers Phil At 13:01 16/05/02 -0400, you wrote: The revised timeseries I made with Tom (and I promised to send, should I send it to you or Tim O?) uses weights determined by the correlation of a timeseries with the nh mean (so it is like a multiregression but does not account for correlation between timeseries which is what tends to give you the overfitting and strong weights of crazy signs, in theory its the second best thing to do but in practice I think it is safer than multiregression). So it is a positive weight highest for timeseries going well with NH mean, and sometimes negative for timeseries that tend to be anticorrelated, but I think there is only 1 case. If you want me to, we can also make one for NH summer. Tom is keen on annual, but I agree with you that summer may be more meaningful. I pre-screened the timeseries by knocking out those with very poor correlations with local temperature. Tom uses that one now, the correlation of it with instrumental is nearly the same as with his old one though, but there are some reasons why he likes the new one better. See you in Thera! Gabi Gabi, Adding this to 1.a.2 is fine. Remove the 'an' before improved on the 5th line. I will be on Thera so we should take the opportunity to discuss these aspects whilst there. I will be there the whole time though arriving a little late (Monday if I recall correctly). Doing what I propose in 1.a.2 will need to involve Mike as we need to get all his data, and a lot more news stuff that has been produced in the last few years that none of us have. What I want to get at most is the weights of each series going into the reconstruction, so we know better which series are really doing the work. These are the ones we want to encourage possible extensions. At present we don't know which contribute most, although what Tom and I do by giving them equal weight may be just as good. See you on Thera. Cheers Phil At 10:14 16/05/02 -0400, you wrote: Hi Tom and Phil, How about this on 1.a.2 , this has "integrate reconstructions" to say we want to combine information. Phil, does that cover what you suggest? Greetings Gabi 2. Assess climate variability on decadal and centennial timescales, from the instrumental and paleo record and from new records, attempt new reconstructions and compare and integrate reconstructions for hemispheric scale climate variability with the goal of obtaining an improved estimates of natural internal and natural forced climate variability (Crowley / Jones). -- ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Gabriele Hegerl - NOTE CHANGE IN ADDRESS FORMAT Department of Earth and Ocean Sciences, Nicholas School for the Environment, Box 90227 Duke University, Durham NC 27708 Ph: 919 684 6167, fax 684 5833 email: hegerl@duke.edu 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 ---------------------------------------------------------------------------- -- ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Gabriele Hegerl - NOTE CHANGE IN ADDRESS FORMAT Department of Earth and Ocean Sciences, Nicholas School for the Environment, Box 90227 Duke University, Durham NC 27708 Ph: 919 684 6167, fax 684 5833 email: hegerl@duke.edu 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 ---------------------------------------------------------------------------- -- ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Gabriele Hegerl - NOTE CHANGE IN ADDRESS FORMAT Department of Earth and Ocean Sciences, Nicholas School for the Environment, Box 90227 Duke University, Durham NC 27708 Ph: 919 684 6167, fax 684 5833 email: hegerl@duke.edu, http://www.env.duke.edu/faculty/bios/hegerl.html Attachment Converted: "C:\EUDORA\Attach\recordsused.ps" Attachment Converted: "C:\EUDORA\Attach\recordclh.psc" Attachment Converted: "C:\EUDORA\Attach\reconstructionsnewphil.as" Attachment Converted: "C:\EUDORA\Attach\proxycompclg1.2.as" Attachment Converted: "C:\EUDORA\Attach\cl6.readme" Attachment Converted: "C:\EUDORA\Attach\cl6.as"