date: Mon, 09 Oct 2006 11:30:01 +0100 from: "Quaternary Science Reviews" subject: Reviewer Invitation for JQSR-D-06-00173 to: Ms. Ref. No.: JQSR-D-06-00173 Title: Hemispheric changes of internal and forced variability recorded in regional climate - imprints of Medieval Warm Period, Little Ice Age and twentieth century warmth in proxy-based temperature reconstruction at high-latitudes of Europe Quaternary Science Reviews Dear Prof Keith R Briffa, You are invited to review the above-mentioned manuscript that has been submitted for publication in Quaternary Science Reviews. The abstract is attached below. Are you available to provide the review? PLEASE DO NOT USE YOUR E-MAIL "REPLY" OPTION TO RESPOND TO THIS INVITATION. Instead, please respond online at http://ees.elsevier.com/jqsr/. You will need to login as a Reviewer: Your username is: KBriffa-255 Your password is: briffa5873 Please select the "New Invitations" link on your Main Menu, then choose to "Accept" or "Decline" this invitation, as appropriate. If you accept this invitation, I would be very grateful if you would return your review by Nov 20, 2006. You may submit your comments online at the above URL. There you will find spaces for confidential comments to the editor, comments for the author and a report form to be completed. To assist you in the reviewing process, I am delighted to offer you full access to Scopus* for 30 days. With Scopus you can search for related articles, references and papers by the same author. You may also use Scopus for your own purposes at any time during the 30-day period. If you already use Scopus at your institute, having this 30 day full access means that you will also be able to access Scopus from home. Access instructions will follow once you have accepted this invitation to review *Scopus is the world's largest abstract and citation database of research information and quality internet sources. With kind regards, Neil Roberts Editor Quaternary Science Reviews ABSTRACT: New tree-ring based analysis for climate variability at regional scale is presented for northern Fennoscandia. Our absolutely dated temperature reconstruction seeks to characterize the shifts and gradual changes in temperature history through the classical climatic periods since AD 750. Warmest and coldest reconstructed 250-year periods occurred AD 931-1180 and AD 1601-1850, respectively. These periods owe significant temporal overlap with the general hemispheric climate variability due to the Medieval Warm Period (MWP) and the Little Ice Age (LIA). Detailed picture of temperature evolution shows that MWP was long ameliorated interval with mean temperatures warmer than temperatures during the following centuries but not warmer than during the 20th century. The LIA seems to follow the two-stage model. We detect the approx. 60-year rhythm, attributable to North Atlantic thermohaline circulation (THC), in the regional climate during the MWP but not during the LIA. THC further appears as an agent behind the initiation and continuation of MWP and the mid-LIA transient warmth. Coldest and warmest of all reconstructed 100-year periods occurred AD 1587-1686 and AD 1895-1994, respectively. These dates bracket the coldest phase of Little Ice Age suggesting that both its initiation and termination were associated with anomalous climatic intervals. Cooling of climate since the MWP until the termination of the LIA follows the hemispheric trend supposedly by orbital forcing, amplification of volcanic signature years and hemispheric vegetation changes with intensifying mechanism from regional forest-limit retreat. Brief comparison of instrumental and proxy-based records shows that the rise in annual and summer temperatures during the late 19th and early 20th century is parallel but not exactly simultaneous. ****************************************** For any technical queries about using EES, please contact Elsevier Reviewer Support at reviewersupport@elsevier.com