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

Abstract

A multiproxy study of sediment cores from Zoñar Lake (37°29′00″N, 4°41′22″W, 300 m a.s.l.) supported by 11 14 C 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 (`Mediaeval 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 and 0.6 cal. kyr BP (AD 1200—1400) and about 400 cal. yr BP (around AD 1600) 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.