date: Wed Aug 10 16:15:52 2005 from: Phil Jones subject: Re: krakatau and 1902 to: Tom Crowley Tom, I've been in contact with Kevin Trenberth daily for the past month or two ! He's normally emailed me by now, but I have some relief today. Phil At 15:18 10/08/2005, you wrote: Phil, Gabi is very busy indeed and it is no coincidence that our departure date comes so shortly after the the CLAs send off their FODs - Gabi seems to be in constant communication with Francis Z. on this. I understand your rationale about high latitude cooling in 1902, but believe me we have seven cores now from Greenland, and one from Mt. Logan, and the 1902 eruption occurs in only two of them - the evidence is pretty strong that the sulphate loading is just not there in high latitudes, so you may be looking at some teleconnective cooling in regions from Europe and eastern N. America -- v. strong PNA with a dash of sulphate? tom Phil Jones wrote: Tom, OK re the data. I thought you'd already gone to Europe. So make a not for when you get back. I presume Gabi will be pleased to send that final Ch 9 file to WGI on Friday. I'll be having next week off. 1902 could be a La Nina as far as global temps occur, but the pattern shows more cooling in higher lats, like typical volcanoes (especially in Europe and eastern N. America). Also there was more than one volcano in the year. Have a good month away ! Cheers Phil At 14:33 10/08/2005, you wrote: Phil, thanks, actually the tree ring density data shows a clear Krakatau cooling in high latitudes, and I have an unpublished composite of paleo tropical proxies that shows cooler temps than you reconstruct. the 1902 sulphate data are pretty good - there is very weak evidence for any type of significant sulphate loading from the eruptions - could you possibly just be having a super la nina? tom ps we leave for europe on sunday, won't be able to get data to you until after I return, sept. 9 Phil Jones wrote: Tom, I can't recall where we might have mentioned this, so here's some papers (below). Figure 2 in the first paper looks the best, but he text doesn't seem to say anything specific. Figure shows Krakatau response is pretty small, compared to Pinatubo and also to the 1902 eruption(s). This paper shows 1902 response is much larger, and larger than Pinatubo. So my take would be 1902 should be large. Is Krakatau smaller because a lot of water might have been involved. Don't forget to send your various datasets when you get a chance. Cheers Phil PS the other two papers may say something - the GRL one especially. I can't seem to find a copy of that. Kelly, P.M., Pengqun, J. and Jones, P.D., 1996: The spatial temperature response to large volcanic eruptions. International Journal of Climatology 16, 537-550. Jones, P.D., Briffa, K.R. and Schweingruber, F.H., 1995: Tree-ring evidence of the widespread effects of explosive volcanic eruptions. Geophysical Research Letters 22, 1333 1336. Briffa, K.R., Jones, P.D., Schweingruber, F.H. and Osborn, T.J., 1998: Influence of volcanic eruptions on Northern Hemisphere summer temperature over the last 600 years. Nature 393, 450-455. At 00:43 10/08/2005, you wrote: Phil, I know you have mentioned before that you cannot find evidence in your instrumental reconstruction for a significant Krakatau cooling - but where do you actually mention it? I would like to cite this because I am finally writing up my ice core calibration comparison with Sato, and our global Krakatau value is slightly (~6%) greater than Pinatubo. also have you ever commented on the lack of cooling from the 1902 eruptions? Myles claims that this has been discussed, but I have not seen it. The reason I ask is that we think that Sato et al have significantly overestimated the aod for these eruptions - most ice cores in both Antarctica and Greenland (and we have examined 22) do not have the event. thanks for any help, regards, tom 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 [1]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 [2]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 ----------------------------------------------------------------------------