Combination of insolation and ice-sheet forcing drive enhanced humidity in northern subtropical regions during MIS 13

QUATERNARY SCIENCE REVIEWS

卷:247

Review

Oliveira, Dulce^1,2  Desprat, Stephanie^3,4  Yin, Qiuzhen⁵  Rodrigues, Teresa^1,2  Naughton, Filipa^1,2  Trigo, Ricardo M.⁶  Su, Qianqian⁵  Grimalt, Joan O.⁷  Alonso-Garcia, Montserrat^1,8  Voelker, Antje H. L.^1,2  Abrantes, Fatima^1,2  Sanchez Goni, Maria Fernanda^3,4 

[1] Univ Algarve, Ctr Ciencias Mar, CCMAR, Campus Gambelas, P-8005139 Faro, Portugal

[2] Inst Portugues Mar & Atmosfera IPMA, Div Geol & Georecursos Marinhos, Av Doutor Alfredo Magalheies Ramalho 6, P-1495165 Alges, Portugal

[3] PSL Univ, Ecole Prat Hautes Etud EPHE, F-33615 Pessac, France

[4] Univ Bordeaux, EPOC, UMR 5805, F-33615 Pessac, France

[5] Catholic Univ Louvain, Georges Lemaitre Ctr Earth & Climate Res, Earth & Life Inst, Louvain La Neuve, Belgium

[6] Univ Lisbon, Inst Dom Luiz, P-1749016 Lisbon, Portugal

[7] Spanish Council Sci Res CSIC, Inst Environm Assessment & Water Res IDAEA, Dept Environm Chem, Barcelona 08034, Spain

[8] Univ Salamanca, Dept Geol Paleontol, Pza Caidos, Salamanca 37008, Spain

关键词: Mid-Brunhes event;    Interglacial MIS 13;    Mediterranean vegetation;    Model-data comparison;    Insolation;    Ice-sheets;   

DOI  :  10.1016/j.quascirev.2020.106573

来源: Elsevier

【 摘 要 】

Marine Isotope Stage (MIS) 13, similar to 533-478 ka, has received particular attention due to the unexpected enhancement of monsoon systems under a cool climate characterized by lower atmospheric CO2 and larger ice volume than many other interglacials. Key questions remain about its regional expression (intensity, climate variability, length), and underlying forcing factors, in particular at the mid-latitudes. Here we examine the SW Iberian vegetation, terrestrial climate and sea surface temperature (SST) variability during MIS 13 by combining pollen and biomarker data from IODP Site U1385 with climate-model experiments. We show, for the first time, that despite strong precessional forcing, MIS 13 stands out for its large forest expansions with a reduced Mediterranean character alternating with muted forest contractions, indicating that this stage is marked by a cool-temperate climate regime with high levels of humidity. Results of our data-model comparison reveal that MIS 13 orbitally driven SW Iberian climate and vegetation changes are modulated by the relatively strong ice-sheet forcing. We find that the Northern Hemisphere ice-sheets prescribed at the MIS 13 climate optimum reinforce the insolation effect by increasing the tree fraction and both winter and summer precipitation. We propose that the interactions between ice-sheets and major atmospheric circulation systems may have resulted in the persistent influence of the mid-latitude cells over the SW Iberian region, which led to intensified moisture availability and reduced seasonality, and, in turn, to a pronounced expansion of the temperate forest. (C) 2020 Elsevier Ltd. All rights reserved.

【 授权许可】

Free