date: Tue, 28 Jun 2005 13:19:02 -0600 from: Raimund Muscheler subject: Re: solar activity to: Keith Briffa Hi Keith, I attached the two papers (Comment to Solanki, Nature, in press) and the review article that we submitted a few weeks ago. Please keep it confidential. Best wishes Raimund >Hi Raimund >sure am interested in this and would like full copy as soon as available >Keith >At 00:05 25/06/2005, you wrote: >>Dear Keith, >> >>Caspar Ammann told me that you are coordinator of the discussion about >>climate change during the last 1000 years. There are conflicting results >>about the changes in solar activity during the last 1000 years (e.g. Bard >>et al., 2000, Usoskin et al., 2003) with potentially important >>implications for the discussion of the influence of natural causes on the >>current climate change. Therefore, we discussed the radionuclide-based >>evidence of past changes in solar activity and the reasons for the >>conflicting results. We also included new calculations about past changes >>in the 14C production rate that we could connect to the instrumental data. >> >>Caspar said that you might be interested to see the paper (I attached the >>title & abstract below). >> >>Best regards >>Raimund >> >> >>Title: >> >>Changes in solar activity during the last 1000 years inferred from >>radionuclide records >> >>Abstract: >>Identification of the causes of past climate change requires detailed >>knowledge of one of the most important natural factors - solar forcing. >>Prior to the period of direct solar observations, radionuclide abundances >>in natural archives provide the best-known proxies for changes in solar >>activity. Here we present two independent reconstructions of changes in >>solar activity during the last 1000 years, which are interred from 14C and >>10Be records. These records exhibit a good agreement that allows us to >>obtain a reliable estimate of past solar magnetic modulation of the >>radionuclide production rates. Differences between 10Be records from >>Antarctica and Greenland indicate that climatic changes have influenced >>the deposition of 10Be during some periods of the last 1000 years. The >>radionuclide-based reconstruction of past changes in solar activity does >>not always agree with the sunspot record, which indicates that the >>coupling between those proxies is not as close as has been assumed by some >>authors. The tree ring 14C record and 10Be from Antarctica indicate that >>recent solar activity is high but not exceptional with respect to the last >>1000 years. >> >> >>Raimund Muscheler >>National Center for Atmospheric Research >>Climate and Global Dynamics Division - Paleoclimatology >>1850 Table Mesa Drive >>Boulder, CO 80305-3000 USA >>tel: 303-497-1399 fax: 303-497-1348 >>email: raimund@ucar.edu >> >> > >-- >Professor Keith Briffa, >Climatic Research Unit >University of East Anglia >Norwich, NR4 7TJ, U.K. > >Phone: +44-1603-593909 >Fax: +44-1603-507784 > >http://www.cru.uea.ac.uk/cru/people/briffa/ Attachment Converted: "c:\eudora\attach\Muscheler_et_al_Nature_Comm.pdf" Attachment Converted: "c:\eudora\attach\Muscheler_et_al_subm_to_ESR.pdf" Raimund Muscheler National Center for Atmospheric Research Climate and Global Dynamics Division - Paleoclimatology 1850 Table Mesa Drive Boulder, CO 80305-3000 USA tel: 303-497-1399 fax: 303-497-1348 email: raimund@ucar.edu