Arid and humid phases in southern Spain during the last 4000 years: the Zoñar Lake record, Córdoba

47 páginas, 2 tablas, 6 figurasA multiproxy study of sediments cores from Zoñar Lake (37º29’00’’N, 4º41’22’’ W, 300 m a.s.l.) supported by 11 14C AMS dates provides the first high-resolution centennial-scale reconstruction of past humidity changes in southern Spain during the last 4000 years. Arid periods occurred prior to 2.9 cal. kyr BP and during 1.3-0.6 cal. kyr BP (Medieval Climate Anomaly). The most humid period occurred during 2.6-1.6 cal. kyr BP encompassing the late Iron Age-Iberian and Roman epochs. Two humid periods of lower intensity occurred between 0.8 – 0.6 cal kyr BP (1200 – 1400 AD) and about 400 cal. yr BP (around 1600 AD) coinciding with the onset of the Little Ice Age. Humid conditions are synchronous with a decline in solar output and seem to correspond to atmospheric patterns similar to negative NAO phases. Arid conditions show better correlation with northern Africa climate evolution suggesting a possible link to subtropical dynamics. The geographic location of Zoñar Lake and the robust chronology provides an opportunity to improve our understanding of the climate evolution in mid latitudes during the Late Holocene and to evaluate subtropical and high latitude factors in Mediterranean climate evolution.Financial support for this study was provided by the Spanish Ministry of Science and Education (projects LIMNOCLIBER REN 2003-09130-CO2-02, IBERLIMNO CGL2004-20236-E, CALIBRE CGL2006-13327-C04/CLI and CGL-2006-2956-BOS) and Andalusian Government (PAI group RNM-328). A. Moreno acknowledges the funding from the European Commission’s Sixth Framework Program (Marie Curie Outgoing International Fellowships, proposal 021673-IBERABRUPT).We thank comments and suggestions from Herb Wright, who helped with a previous version of the manuscript, Francisco Mezquita and Javier Marco for their advice on ostracod identification and José.S. Carrión and Noemí Fuentes for pollen samples preparation. We also thank Achim Brauer for his support and dedication during the varve counting. We are also very grateful to the LRC (Minnesota, USA), and particularly to Doug Schnuremberger, Mark Shapley and Anders Noren for making possible the 2004 expedition. A.C. Stevenson and an anonymous reviewer provided constructive criticisms and suggestions.Peer reviewe