date: Mon, 29 Nov 2004 22:54:35 UT from: grlonline@agu.org subject: 2004GL021732 Request to Review from Geophysical Research Letters to: K.Briffa@uea.ac.uk Dear Dr. Briffa: Would you be willing and available to review "Statistical distributions of ice core sulfate from climatically relevant volcanic eruptions" by Philippe Naveau, Caspar Ammann, submitted for possible publication in the Geophysical Research Letters. The manuscript's abstract is: Quantitative knowledge of external climate forcing is required for accurately attributing past climatic changes. Information on volcanic activity over the past millennium has primarily been drawn from high-latitude ice cores. A few large events with distinct signatures in the ice are well known and they are commonly used as marker events to synchronize time scales in individual ice cores. In the past decade different efforts have been undertaken to systematically identify lesser known eruptions and to develop time series of past volcanic forcing. Here we mathematically quantify the distribution of the magnitude of volcanic events that have a climatic relevance during the past millennium. Volcanic sulfate magnitudes of such events clearly exhibit a ``heavy tailed" extreme value distribution. Indeed, the climatically relevant eruptions are only the extremes of global volcanic activity. This characterization of volcanic amplitude is a fundamental step in detection and attribution studies of past natural forcing and of its effects on climate. If you agree to review this manuscript, I would ask for your comments within 14 days from your acceptance. To ACCEPT, click on the link below: If you are unable to review this manuscript at this time, I would appreciate any suggestions of other potential reviewers who would be qualified to examine this manuscript. (Via reply e-mail.) To DECLINE, click on the link below: If you have any questions or need more information feel free to reply to this e-mail. Thank you for your consideration and support of Geophysical Research Letters. Sincerely, James E. Saiers Editor Geophysical Research Letters