Data/hora: 26/07/2024 22:55:13

Provedor de dados: 	Institutional Archive of Ifreme (ArchiMer)	
País: 	France	
Título: 	Deglacial delta δ18 and hydrologic variability in the tropical Pacific and Indian Oceans	
Autores: 	Gibbons, Fern T.; Oppo, Delia W.; Mohtadi, Mahyar; Rosenthal, Yair; Cheng, Jun; Liu, Zhengyu; Linsley, Braddock K.	
Data: 	2014-02	
Ano: 	2014	
Palavras-chave: 	Indo-Pacific; Eastern Equatorial Pacific; Delta O-18 of seawater; Deglaciation; Heat transport.	
Resumo: 	Evidence from geologic archives suggests that there were large changes in the tropical hydrologic cycle associated with the two prominent northern hemisphere deglacial cooling events, Heinrich Stadial 1 (HS1; similar to 19 to 15 kyr BP; kyr BP = 1000 yr before present) and the Younger Dryas (similar to 12.9 to 11.7 kyr BP). These hydrologic shifts have been alternatively attributed to high and low latitude origin. Here, we present a new record of hydrologic variability based on planktic foraminifera-derived delta O-18 of seawater (delta O-18(sw)) estimates from a sediment core from the tropical Eastern Indian Ocean, and using 12 additional delta O-18(sw) records, construct a single record of the dominant mode of tropical Eastern Equatorial Pacific and Indo-Pacific Warm Pool (IPWP) hydrologic variability. We show that deglacial hydrologic shifts parallel variations in the reconstructed interhemispheric temperature gradient, suggesting a strong response to variations in the Atlantic Meridional Overturning Circulation and the attendant heat redistribution. A transient model simulation of the last deglaciation suggests that hydrologic changes, including a southward shift in the Intertropical Convergence Zone (ITCZ) which likely occurred during these northern hemisphere cold events, coupled with oceanic advection and mixing, resulted in increased salinity in the Indonesian region of the IPWP and the eastern tropical Pacific, which is recorded by the delta O-18(sw) proxy. Based on our observations and modeling results we suggest the interhemispheric temperature gradient directly controls the tropical hydrologic cycle on these time scales, which in turn mediates poleward atmospheric heat transport.	
Tipo: 	Text	
Idioma: 	Inglês	
Identificador: 	https://archimer.ifremer.fr/doc/00496/60737/65207.pdf

https://archimer.ifremer.fr/doc/00496/60737/65208.pdf

https://archimer.ifremer.fr/doc/00496/60737/65209.txt

DOI:10.1016/j.epsl.2013.11.032

https://archimer.ifremer.fr/doc/00496/60737/	
Editor: 	Elsevier Science Bv	
Formato: 	application/pdf	
Fonte: 	Earth And Planetary Science Letters (0012-821X) (Elsevier Science Bv), 2014-02 , Vol. 387 , P. 240-251	
Fonte: 	info:eu-repo/semantics/openAccess

restricted use