Palaeoclimate and palaeoceanographic conditions in the westernmost mediterranean over the last millennium: An integrated organic and inorganic approach

Previous studies have revealed the excellence of the westernmost Mediterranean records for reconstructing climate conditions over the last two millennia. In particular, inorganic and organic proxies have revealed a coherent signal of climate and oceanographic responses during this time. Here we compare and integrate both proxy records for reconstructing climate and oceanographic conditions with focus on the last millennium. The higher temperatures indicated by lipid-based proxies during the Medieval Climate Anomaly (MCA) are coincident with drier conditions indicated by inorganic proxies. In contrast, lower temperatures and humid conditions are indicated during the Little Ice Age (LIA). The industrial period was characterized by increasing humidity in comparison with the previous LIA. However, a progressive aridification occurred since the second half of the twentieth century, coexisting with a warming trend and higher contribution of C3 grasses. Proxy records are also interpreted to show Atlantic water inflow at AD 1450 and 1950 and an intensification of the upwelling conditions coinciding with a prolonged positive North Atlantic Oscillation (NAO) phase in the intervals AD 1000–1450 and 1960–1990. Large-scale oceanic–atmospheric circulation patterns (the NAO and the Atlantic meridional circulation) and solar irradiance variations seem to have played the major key role during the last millennium, together with anthropogenic contributions in the more recent record.This study was supported by the European Regional Development Fund (ERDF) co-financed grants CGL2012-32659 from MINECO (Secretaría de Estado de Investigación, Spain), RNM-5212 and RNM-179 from Junta de Andalucía (Spain), and the European Research Council under the Seventh Framework Programme (FP7/2007-2013)/ERC (Grant Agreement 226600). The Training-Through-Research Programme is also acknowledged. Analyses were performed at the Andalusian Institute of Earth Sciences (CSIC-UGR), the Centre for scientific Instrumentation (CIC-UGR), Poznan Radiocarbon Laboratory (Poland), SGS Minerals Services (Canada) and the Royal Netherlands Institute for Sea Research (NIOZ). J.G-O. and P.M. want to thank the support of the Generalitat de Catalunya to MERS (2014 SGR – 1356). P.M. was funded through the ICREA Academia prize of the Generalitat de Catalunya. V.N.-M. acknowledges support through the LOEWE funding programme of Hesse’s Ministry of Higher Education, Research and the Arts, and the 7.FP, COFUND, Goethe International Postdoc Programme GO-IN, No. 291776.Peer Reviewe