Late Quaternary climate variability in Southern Ocean Atlantic Sector

• Main Author: Xiao, Wenshen
• Format: Thesis
• Language: unknown
• Published: Univ. Bremen 2011
• Subjects: Antarc*; Antarctic; Bouvet Island; Drake Passage; Scotia Sea; Southern Ocean
• Online Access: https://epic.awi.de/id/eprint/52119/; https://elib.suub.uni-bremen.de/peid/D00102009.html; https://hdl.handle.net/10013/epic.dc17c07a-2540-41aa-8e36-adaa76dcba1c

Climate variability of the late Quaternary, especially the Last Glacial (LG) to the Holocene, has become the most heated topic for the recent decades, which helps to better understand the shape of current and future climate on our planet. The long term glacial/interglacial changes have been associated to insolation changes controlled by earth’s orbit, whereas the millennial scale variations are mostly accepted to be modulated by the “bipolar seesaw” mechanism which redistributes heat between the northern and southern hemispheres through the Atlantic Meridional Overturning Circulation (AMOC). The validation of such hypothesis is hampered by the very limited high resolution records from the high latitudes Southern Ocean. Situated at the southern end of the AMOC, Southern Ocean Atlantic sector represents one of the key regions for understanding the global climate change. The warm and cold water routes (WWR, south of Africa and CWR, Drake Passage/Scotia Sea) connect the South Atlantic to South Indian and Pacific Oceans, respectively; and the Weddell Gyre connects the open ocean South Atlantic to the Western Antarctic Shelf Ice (WASI), where nowadays the cold surface water and Antarctic Bottom Water (AABW) are generated beneath. These water masses represent the most important constituents of the AMOC in the Southern Hemisphere. This PhD project generated a series of new diatom based high resolution marine records covering wide area of the high latitudes South Atlantic, including from the Bouvet Island area and the Scotia Sea, aimed to provide new insights of the response and drive in Southern Ocean in the context of late Quaternary global climate change. With focusing on the LG to Holocene time period, by integration of our new generated and other existing records from the Southern Ocean Atlantic and Western Indian sectors, a detailed regional age model for the past 30 kyrs is established by AMS 14C dating and regional core correlation, which can be a template for further paleoenvironment reconstructions in this ...