The dynamic relationship between temperate and tropical circulation systems across South Africa since the last glacial maximum

QUATERNARY SCIENCE REVIEWS

卷:174

Article

Chase, Brian M.¹  Chevalier, Manuel²  Boom, Arnoud³  Carr, Andrew S.³ 

[1] Univ Montpellier, Inst Sci Evolut Montpellier, UMR 5554, CNRS, Bat 22,CC061,Pl Eugene Bataillon, F-34095 Montpellier 5, France

[2] Univ Lausanne, Geopolis, Inst Earth Surface Dynam, Quartier UNIL Mouline, Batiment Geopolis, CH-1015 Lausanne, Switzerland

[3] Univ Leicester, Sch Geog Geol & Environm, Leicester LE1 7RH, Leics, England

关键词: Last glacial maximum;    Holocene;    Palaeoclimate;    Climate dynamics;    South Africa;    Hyrax middens;    Stable isotopes;   

DOI  :  10.1016/j.quascirev.2017.08.011

来源: Elsevier

【 摘 要 】

A fundamental and long-standing question of southern African palaeoclimatology is the way tropical and temperate climate system dynamics have influenced rainfall regimes across the subcontinent since the Last glacial maximum. In this paper, we analyse a selection of recently published palaeoclimate reconstructions along a southwest-northeast transect across South Africa. These records span the last 22,000 years, and encompass the transition between the region's winter and summer rainfall zones. In synthesis, these records confirm broad elements of the dominant paradigm, which proposes an inverse coeval relationship between temperate and tropical systems, with increased precipitation in the winter (summer) rainfall zone during glacial (interglacial) periods. Revealed, however, is a substantially more complex dynamic, with millennial-scale climate change events being strongly - even predominantly - influenced by the interaction and combination of temperate and tropical systems. This synoptic forcing can create same sign anomalies across the South African rainfall zones, contrary to expectations based on the classic model of phase opposition. These findings suggest a new paradigm for the interpretation of southern African palaeoenvironmental records that moves beyond simple binary or additive influences of these systems. (C) 2017 Published by Elsevier Ltd.

【 授权许可】

Free