This study presents the first well-dated high resolution stable isotope (δ18O and δ13C) and trace element (Mg and Sr) speleothem records from southwestern Morocco covering the last 1000 yrs. Our records reveal substantial decadal to multidecadal swings between dry and humid periods, consistent with regional paleorecords with prevailing dry conditions during the Medieval Climate Anomaly (MCA), wetter conditions during the second part of the Little Ice Age (LIA), and a trend towards dry conditions during the current warm period. These coherent regional climate signals suggest common climate controls. Statistical analyses indicate that the climate of southwestern Morocco remained under the combined influence of both the North Atlantic Oscillation (NAO) and the Atlantic Multidecadal Oscillation (AMO) over the last millennium. Interestingly, the generally warmer MCA and colder LIA at longer multidecadal timescales probably influenced the regional climate in North Africa through the influence on Sahara Low which weakened and strengthened the mean moisture inflow from the Atlantic Ocean during the MCA and LIA respectively.
|Original language||English (US)|
|Number of pages||10|
|Journal||Earth and Planetary Science Letters|
|State||Published - Oct 15 2017|
Bibliographical noteFunding Information:
This work was supported by the CLIMACTE Tripartite Cooperative Project (IRD-France/CNPq-Brazil/APGMV-Africa grant 457400/2012-9), the PRIMO: IRD-CNPq project, and the German Research Foundation (DFG; WA3532/1-1) and the strong collaboration between the Laboratory of Speleological studies at the Institute of Geoscience in the University of Sao Paulo (Brazil), the Isotope Laboratory in the University of Minnesota (U.S.A.), the Institute of Global Environmental Change in Xi'an Jiaotong University (China) and the Laboratory of Applied Geology and Geo-Environment in Ibn Zohr University (Morocco). We would like to express our gratitude to the CNRST-Morocco for the scholarship awarded to Yassine Ait Brahim. We are also grateful to Augusto Auler and the Associations of Speleologists in Agadir (ASS and ASA) for their help with the field work. The authors also thank the editor and reviewers for their constructive comments which helped improving the paper.
© 2017 Elsevier B.V.
- Atlantic Oscillation
- Sahara Low
- hydroclimate changes
- last millennium
- southwestern Morocco