Investigating the 8.2 ka event in northwestern Madagascar: Insight from data-model comparisons

QUATERNARY SCIENCE REVIEWS

卷:204

Article

Voarintsoa, Ny Riavo G.^1,8  Matero, Ilkka S. O.²  Railsback, L. Bruce¹  Gregoire, Lauren J.²  Tindall, Julia²  Sime, Louise³  Cheng, Hai^4,5  Edwards, R. Lawrence⁵  Brook, George A.⁶  Kathayat, Gayatri⁴  Li, Xianglei⁴  Rakotondrazafy, Amos Fety Michel⁷  Razanatseheno, Marie Olga Madison⁷ 

[1] Univ Georgia, Dept Geol, Athens, GA 30602 USA

[2] Univ Leeds, Sch Earth & Environm, Leeds LS2 9JT, W Yorkshire, England

[3] British Antarctic Survey, Ice Dynam & Paleoclimate, Cambridge CB3 0ET, England

[4] Xi An Jiao Tong Univ, Inst Global Environm Change, Xian 710049, Shaanxi, Peoples R China

[5] Univ Minnesota, Dept Earth Sci, Minneapolis, MN 55455 USA

[6] Univ Georgia, Dept Geog, Athens, GA 30602 USA

[7] Univ Antananarivo, Ment Sci Terre & Environm Domaine Sci & Technol, Antananarivo, Madagascar

[8] Hebrew Univ Jerusalem, Inst Earth Sci, Jerusalem, Israel

关键词: Holocene;    Speleothems;    Stable isotopes;    ITCZ-Monsoon;    Madagascar;    8.2 ka event;    Paleoclimate modeling;    Data-model comparisons;    AMOC;   

DOI  :  10.1016/j.quascirev.2018.11.030

来源: Elsevier

【 摘 要 】

The 8.2 ka event is a well-known cooling event in the Northern Hemisphere, but is poorly understood in Madagascar. Here, we compare paleoclimate data and outputs from paleoclimate simulations to better understand it. Records from Madagascar suggest two distinct sub-events (8.3 ka and 8.2 ka), that seem to correlate with records from northern high latitude. This could indicate causal relationships via changes in the Atlantic Meridional Overturning Circulation (AMOC) with changes in moisture source's delta O-18, and changes in the mean position of the Inter-Tropical Convergence Zone (ITCZ), as climate modelling suggests. These two sub-events are also apparent in other terrestrial records, but the climatic signals are different. The prominent 8.2 ka sub-event records a clear antiphase relationship between the northern and southern hemisphere monsoons, whereas such relationship is less evident during the first 8.3 1

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