Speleothem records decadal to multidecadal hydroclimate variations in southwestern Morocco during the last millennium

2017

Article référencé dans le Web of Science WOS:000412259400001

Brahim Y. A., Cheng H., Sifeddine Abdelfettah, Wassenburg J. A., Cruz F. W., Khodri Myriam, Sha L., Perez-Zanon N., Beraaouz E., Apaestegui J., Guyot Jean-Loup, Jochum K. P., Bouchaou L.

Earth and Planetary Science Letters, 2017, 476, p. 1-10 ISSN 0012-821X

This study presents the first well-dated high resolution stable isotope (delta O-18 and delta C-13) 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.

Sciences du milieu [021] ; Hydrologie [062] ; Géologie et formations superficielles [064]

MAROC ; ATLANTIQUE ; SAHARA

Fonds IRD [F B010071067]

fdi:010071067