Abstract
Hydroclimate changes in Northern Africa reflect the interplay between mid-latitude westerlies and the West African monsoon, along with their intensity variations. The response of these atmospheric circulation systems to changing boundary conditions and their impacts on the precipitation during past episodes of climate change remain unconstrained, because of scarcity of well-dated terrestrial hydroclimate records from Northern Africa that reach beyond the Holocene interglacial. We present a 300,000-year hydroclimate record inferred from periods of speleothem formation from Tunisia, located in the northernmost Africa. This record captures the alternation of humid and arid phases during glacial and interglacial climate states, as well as the superimposed millennial-scale events. Humid conditions prevailed during the interglacial periods, while arid conditions were associated to glacial boundary conditions. Cave evidence suggests that these humid phases in northernmost Africa could mainly be attributed to the southward shift and strengthening of the mid-latitude westerlies and the Mediterranean storm track during interglacials, and vice versa in glacials. A comparison with palaeolake records from the Sahara suggests suggests that during interglacials winter westerlies and the summer West African Monsoon were crucial to bring moisture in Northern Africa, contributing to the development of wet conditions in the Sahara.
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Data availability
All speleothem data are all provided in the Supplementary Information and also publicly available at the Zenodo repository: https://zenodo.org/records/18263360.
Code availability
The modified KDE code, modified from ref. 25, is available in the supplementary.
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Acknowledgements
This work and U-Th dating received support from the National Science and Technology Council, Taiwan, ROC, under grants 114-2116-M-002-016-MY3 (C.-C.S.), 111-2116-M-002-022-MY3 (C.-C.S.), 111-2926-I-002-510-G (C.-C.S.), the Higher Education Sprout Project of the Ministry of Education, Taiwan, ROC, 112L901001 (C.-C.S.), National Taiwan University, Taiwan, ROC, 112L894202 (C.-C.S.). This research also received support from the Pilot Programme for Elite Doctoral Scholarship from the Ministry of Science and Technology and National Taiwan University (Y.-C.C.), the EDUFI Fellowship from the Finnish National Agency for Education (Y.-C.C.), and Research Council of Finland 341622 (A.K.). We would like to express our deep gratitude to the Tunisian Ministry of Higher Education and Scientific Research for financial support and to the Caving and Climbing Association of Zaghouan-Tunisia, led by Mr. Maher Mlaouhia for the assistance during fieldwork. All speleothem samples used in this study were collected with official permission. We sincerely thank Dr. Rieneke Weij for sharing the initial KDE frequency curves and for her valuable suggestions; the final version presented in this manuscript was modified by the authors. We thank the three anonymous reviewers for their constructive comments and suggestions, which helped improve the clarity and quality of this manuscript.
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C.-C.S. and H.D. led the programme; H.D., C.-C.S. and M.A.L. initiated this collaborative project; Y.-C.C. designed this research topic; C.-C.S., Y.-C.C., H.D., E.S., M.A.L., H.B.O., H.S., and A.K. conducted the fieldwork; H.D. and E.S. collected and provided cave information; Y.-C.C. and C.-C.S. conducted U-Th dating; Y.-C.C. created the figures; Y.-C.C. wrote the initial manuscript with input from H.S., A.K., and C.-C.S.; Y.-C.C., G.M., C.-C.S., and S.F. revised the manuscript with input from all co-authors.
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Chung, YC., Dhaouadi, H., Marino, G. et al. Three hundred thousand years of multi-millennial hydroclimate variability in Northern Africa based on speleothem records from Tunisia. Commun Earth Environ (2026). https://doi.org/10.1038/s43247-026-03236-1
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DOI: https://doi.org/10.1038/s43247-026-03236-1
