气候变化领域集成服务门户(CCPortal): Sea-surface temperature; productivity and hydrological changes in the Northern Indian Ocean (Maldives) during the interval ~575-175 ka (MIS 14 to 7)

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DOI	10.1016/j.palaeo.2019.109376
	Sea-surface temperature; productivity and hydrological changes in the Northern Indian Ocean (Maldives) during the interval ~575-175 ka (MIS 14 to 7)
	Alonso-Garcia M.; Rodrigues T.; Abrantes F.; Padilha M.; Alvarez-Zarikian C.A.; Kunkelova T.; Wright J.D.; Betzler C.
发表日期	2019
ISSN	0031-0182
卷号	536
英文摘要	The South Asian Monsoon (SAM) drives seasonal changes in the atmospheric and ocean circulation of the tropical Indian Ocean, affecting precipitation on land and oceanic primary productivity. This work examined sediments from the International Ocean Discover Program (IODP) Site U1467 (IODP Expedition 359) located in the Maldives Inner Sea (Northern Indian Ocean) at a water depth of 487 m. The Maldives Inner Sea is a perfect location to study past changes in tropical climate and ocean circulation related to monsoon dynamics in the Equatorial Indian Ocean. This study focuses on the ~575-175 ka interval, from Marine Isotope Stage (MIS) 14 to 7, an important period for human evolution and dispersal to Eurasia. We reconstructed sea-surface temperature (SST), based on alkenone unsaturation index (U37 K'), hydrological changes, based on terrestrial input of n-alkanes, and past surface ocean productivity, based on total C37 alkenones concentration. The U37 K' -SST record shows a difference of about 1.5 °C between glacial and interglacial periods, clearly showing all stages and substages from MIS 14 to 7, and revealing a connection between ice sheets extension and SST at the equatorial region. The n-alkanes concentration and average chain length index indicate vegetation changes at the Indian Peninsula with drier conditions generally associated with glacial periods. Precipitation increases abruptly at the end of terminations, lasting for a variable time interval in each interglacial period, except for MIS 13. However, other mechanisms superimposed to the glacial-interglacial forcing, such as the Indian Ocean Dipole (IOD) mode, have been invoked to explain shorter-scale variability in precipitation over India. The total alkenone concentration record indicates that primary productivity at Site U1467 is strongly associated with orbital changes, probably related to the summer inter-tropical insolation gradient (SITIG, 23N-23S on June 21st). High primary productivity occurred during intervals of low SITIG, which resulted in strong inter-monsoon (April-May and October-November) Indian Ocean Equatorial Westerlies (IEW) and reduced precipitation in the equatorial region. This mechanism may also be related to the IOD, which affects the strength of the IEW. © 2019 Elsevier B.V.
英文关键词	Alkanes; Alkenones; Asian monsoon; Mid-Brunhes event; Pleistocene climate; SITIG
语种	英语
scopus关键词	alkane; alkenone; biological production; Brunhes chron; hydrological modeling; marine isotope stage; monsoon; paleoclimate; Pleistocene; sea surface temperature; Maldives
来源期刊	Palaeogeography, Palaeoclimatology, Palaeoecology
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/150758
作者单位	Instituto Português Do Mar e da Atmosfera (IPMA), Av. Alfredo Magalhães Ramalho 6, Lisboa, 1495-006, Portugal; Centro de Ciências Do Mar (CCMAR), Universidade Do Algarve, Campus de Gambelas, Faro, 8005-139, Portugal; Universidad de Salamanca, Geology Department, Pza de Los Caídos S/n, Salamanca, 37008, Spain; International Ocean Discovery Program, Texas A&M University, Discovery Drive, College Station, TX 77845, United States; Ocean and Earth Science, National Oceanography Centre Southampton, University of Southampton, Waterfront Campus, European Way, Southampton, SO14 3ZH, United Kingdom; Department of Earth and Planetary Sciences, Rutgers UniversityNJ, United States; Institute of Geology, CEN, University of Hamburg, Bundesstrasse 55, Hamburg, 20146, Germany
推荐引用方式 GB/T 7714	Alonso-Garcia M.,Rodrigues T.,Abrantes F.,et al. Sea-surface temperature; productivity and hydrological changes in the Northern Indian Ocean (Maldives) during the interval ~575-175 ka (MIS 14 to 7)[J],2019,536.
APA	Alonso-Garcia M..,Rodrigues T..,Abrantes F..,Padilha M..,Alvarez-Zarikian C.A..,...&Betzler C..(2019).Sea-surface temperature; productivity and hydrological changes in the Northern Indian Ocean (Maldives) during the interval ~575-175 ka (MIS 14 to 7).Palaeogeography, Palaeoclimatology, Palaeoecology,536.
MLA	Alonso-Garcia M.,et al."Sea-surface temperature; productivity and hydrological changes in the Northern Indian Ocean (Maldives) during the interval ~575-175 ka (MIS 14 to 7)".Palaeogeography, Palaeoclimatology, Palaeoecology 536(2019).