Gradual South-North Climate Transition in the Atlantic Realm Within the Younger Dryas

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Zhang, Haiwei ^[1] ; Cheng, Hai ^{[2, 1]} ; Spoetl, Christoph ^[3] ; Zhang, Xu ^[4] ; Cruz, Francisco W. ^[5] ; Sinha, Ashish ^[6] ; Auler, Augusto S. ^[7] ; Strikis, Nicolas M. ^{[5, 8]} ; Wang, Xianfeng ^[9] ; Kathayat, Gayatri ^[1] ; Li, Xianglei ^[2] ; Li, Hanying ^[1] ; Perez-Mejias, Carlos ^[1] ; Cai, Yanjun ^[1] ; Ning, Youfeng ^[1] ; Edwards, Richard Lawrence ^[2]

Afiliação do(s) autor(es)

^[1] Xi An Jiao Tong Univ, Inst Global Environm Change, Xian - Peoples R China

^[2] Univ Minnesota, Dept Earth Sci, Minneapolis, MN 55455 - USA

^[3] Univ Innsbruck, Inst Geol, Innsbruck - Austria

^[4] Lanzhou Univ, Ctr Pan Third Pole Environm Pan TPE, Coll Earth & Environm Sci, Key Lab Western Chinas Environm Syst, Minist Educ, Lanzhou - Peoples R China

^[5] Univ Sao Paulo, Inst Geociencias, Sao Paulo - Brazil

^[6] Calif State Univ Dominguez Hills, Dept Earth Sci, Carson, CA 90747 - USA

^[7] Inst Carste, Belo Horizonte, MG - Brazil

^[8] Univ Fed Fluminense, Dept Geoquim, Niteroi, RJ - Brazil

^[9] Nanyang Technol Univ, Earth Observ Singapore, Singapore - Singapore

• Tipo de documento: Artigo Científico
• Fonte: Geophysical Research Letters; v. 48, n. 8 APR 28 2021.
• Citações Web of Science: 0

Resumo

The abrupt climate event Younger Dryas (YD) has been extensively studied; however, its structure is still poorly understood. Climate in northeastern Brazil is very sensitive to the latitudinal position of the intertropical convergence zone (ITCZ) associated with abrupt climate change in the Atlantic. Here, we report changes in the ITCZ position within the YD by using precise speleothem multiproxy records from northeastern Brazil. We provide evidence for a gradual northward migration of the ITCZ preceding poleward shifts of the westerlies and the polar front in northern high latitudes within the YD. This can be attributed to gradual increase in atmospheric CO2 concentration as a consequence of the weakening Atlantic Meridional Overturning Circulation (AMOC). We suggest that a persistent increase in atmospheric CO2 might have triggered a resumption of the AMOC and reorganization of the atmosphere circulation in the Atlantic during the mid-YD. Plain Language Summary The Younger Dryas (YD) is the most recent millennial-scale abrupt climate event in Earth history. Although its origin has been extensively studied, its structure is still poorly understood. Climate in northeastern Brazil is very sensitive to the latitudinal position of the intertropical convergence zone (ITCZ) responds to abrupt climate change in the Atlantic (e.g., YD). By using stable isotope and trace element proxy records of speleothem from Toca da Boa Vista Cave, northeastern Brazil, together with other paleoclimatic records in the Atlantic realm, we provide evidence for a gradual northward migration of the ITCZ preceding poleward shifts of the westerlies and the polar front in northern high latitudes within the YD. This can be attributed to a gradual increase in atmospheric CO2 concentration under the situation of weakening Atlantic Meridional Overturning Circulation (AMOC). A persistent increase in atmospheric CO2 concentration might have triggered a resumption of the AMOC and reorganization of the atmosphere circulation in the Atlantic during the mid-YD. (AU)

• Processo FAPESP: 17/50085-3 - PIRE: educação e pesquisa em clima das Américas usando os exemplos de anéis de árvores e espeleotemas (PIRE-CREATE)
• Beneficiário: Francisco William da Cruz Junior
• Modalidade de apoio: Auxílio à Pesquisa - Temático