title: 9,400 years of cosmic radiation and solar activity from ice cores and tree rings.
abstract: Understanding the temporal variation of cosmic radiation and solar activity during the Holocene is essential for studies of the solar-terrestrial relationship. Cosmic-ray produced radionuclides, such as (10)Be and (14)C which are stored in polar ice cores and tree rings, offer the unique opportunity to reconstruct the history of cosmic radiation and solar activity over many millennia. Although records from different archives basically agree, they also show some deviations during certain periods. So far most reconstructions were based on only one single radionuclide record, which makes detection and correction of these deviations impossible. Here we combine different (10)Be ice core records from Greenland and Antarctica with the global (14)C tree ring record using principal component analysis. This approach is only possible due to a new high-resolution (10)Be record from Dronning Maud Land obtained within the European Project for Ice Coring in Antarctica in Antarctica. The new cosmic radiation record enables us to derive total solar irradiance, which is then used as a proxy of solar activity to identify the solar imprint in an Asian climate record. Though generally the agreement between solar forcing and Asian climate is good, there are also periods without any coherence, pointing to other forcings like volcanoes and greenhouse gases and their corresponding feedbacks. The newly derived records have the potential to improve our understanding of the solar dynamics and to quantify the solar influence on climate.
authors.affiliation: Swiss Federal Institute of Aquatic Science and Technology, Eawag, Überlandstrasse 133, 8600 Dübendorf, Switzerland. friedhelm.steinhilber@eawag.ch
authors.forename: Friedhelm
authors.initials: F
authors.lastname: Steinhilber
authors.forename: Jose A
authors.initials: JA
authors.lastname: Abreu
authors.forename: Jürg
authors.initials: J
authors.lastname: Beer
authors.forename: Irene
authors.initials: I
authors.lastname: Brunner
authors.forename: Marcus
authors.initials: M
authors.lastname: Christl
authors.forename: Hubertus
authors.initials: H
authors.lastname: Fischer
authors.forename: Ulla
authors.initials: U
authors.lastname: Heikkilä
authors.forename: Peter W
authors.initials: PW
authors.lastname: Kubik
authors.forename: Mathias
authors.initials: M
authors.lastname: Mann
authors.forename: Ken G
authors.initials: KG
authors.lastname: McCracken
authors.forename: Heinrich
authors.initials: H
authors.lastname: Miller
authors.forename: Hiroko
authors.initials: H
authors.lastname: Miyahara
authors.forename: Hans
authors.initials: H
authors.lastname: Oerter
authors.forename: Frank
authors.initials: F
authors.lastname: Wilhelms
mesh_terms: D000864:Antarctic Regions; D001608:Beryllium; D002250:Carbon Radioisotopes / Q000032:analysis; D002980:Climate; D057231:Climate Change; D003359:Cosmic Radiation; D006116:Greenland; D006801:Humans; D046448:Ice Cover / Q000737:chemistry*; D025341:Principal Component Analysis; D011868:Radioisotopes / Q000032:analysis; D019445:Solar Activity; D013997:Time Factors; D014197:Trees / Q000737:chemistry*
chemical_list: D002250:Carbon Radioisotopes; D011868:Radioisotopes; D001608:Beryllium