High-resolution multiproxy analysis of a sediment core from high-elevation lake Bastani

North Africa is the largest source of mineral dust on Earth, which has multiple impacts on the climate system; however, our understanding of decadal to centennial changes in African dust emissions over the last few millenniums is limited. Here, we present a high-resolution multiproxy analysis of sediment core from high-elevation lake Bastani, in Corsica Island to reconstruct past African dust inputs to the Western Mediterranean area over the last 3150 yrs cal BP. Clay Mineralogy with palygorskite and clay ratio associated to geochemical data allows us to identify that terrigenous fluxes are almost exclusively related to atmospheric dust deposition from the West Sahara and Sahel areas over this period. High resolution geochemical contents provide a reliable proxy of Saharan dust inputs with millennial to centennial scale variations. Millennial variations have been correlated to the long term southward migration of the Intertropical Convergence Zone (ITCZ) with an increase of dust input since 1070 yrs cal BP. This correlation suggests a strong link with ITCZ and could reflect the increased availability of dust sources to be mobilized with an increase in wind and a decrease in precipitation over West and North Africa. For centennial to decadal variations, wavelet analyses show that since 1070 yr cal BP, North Atlantic Oscillation (NAO) is the main climatic forcing with an increase of Saharan dust input during positive phase, as suggested by previous study over the last decades. However, when ITCZ is in a northern position, before 1070 yr cal BP, wavelet analyses indicate that total solar irradiance (TSI) is the main forcing factor, with an increase of African dust input during low TSI. With climate reanalysis over the instrumental era, during low TSI we observe a significant negative anomaly in pressure over Africa which is known to increase the dust transport. These two climatic forcing factors (NAO, TSI) modulate Saharan dust inputs to the Mediterranean area at centennial timescale through changes in wind and transport pathways

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Cite this as

Sabatier, Pierre (2020). Dataset: High-resolution multiproxy analysis of a sediment core from high-elevation lake Bastani. https://doi.org/10.1594/PANGAEA.910655

DOI retrieved: 2020

Additional Info

Field Value
Imported on November 30, 2024
Last update November 30, 2024
License CC-BY-4.0
Source https://doi.org/10.1594/PANGAEA.910655
Author Sabatier, Pierre
Given Name Pierre
Family Name Sabatier
Source Creation 2020
Publication Year 2020
Resource Type application/zip - filename: Sabatier_2020
Subject Areas
Name: Atmosphere

Name: Lithosphere

Related Identifiers
Title: Past African dust inputs in the western Mediterranean area controlled by the complex interaction between the Intertropical Convergence Zone, the North Atlantic Oscillation, and total solar irradiance
Identifier: https://doi.org/10.5194/cp-16-283-2020
Type: DOI
Relation: References
Year: 2020
Source: Climate of the Past
Authors: Sabatier Pierre , Nicolle Marie , Piot Christine , Colin Christophe , Debret Maxime , Swingedouw Didier , Perrette Yves , Bellingery Marie-Charlotte , Chazeau Benjamin , Develle Anne-Lise , Leblanc Maxime , Skonieczny Charlotte , Copard Yoann , Reyss Jean-Louis , Malet Emmanuel , Jouffroy-Bapicot Isabelle , Kelner Maëlle , Poulenard Jérôme , Didier Julien , Arnaud Fabien , Vannière Boris .