Deglacial intermediate water reorganization: new evidence from the Indian Ocean

• Published in: Climate of the Past
• Main Authors: S. Romahn, A. Mackensen, J. Groeneveld, J. Pätzold
• Format: Article in Journal/Newspaper
• Language: English
• Published: Copernicus Publications 2014
• Subjects: geo; envir; Antarctic; Indian; Southern Ocean; Antarc*
• Online Access: https://doi.org/10.5194/cp-10-293-2014; http://www.clim-past.net/10/293/2014/cp-10-293-2014.pdf; https://doaj.org/article/cd1de08bee3649539bb39f8c3b962ffa

The importance of intermediate water masses in climate change and ocean circulation has been emphasized recently. In particular, Southern Ocean Intermediate Waters (SOIW), such as Antarctic Intermediate Water and Subantarctic Mode Water, are thought to have acted as active interhemispheric transmitter of climate anomalies. Here we reconstruct changes in SOIW signature and spatial and temporal evolution based on a 40 kyr time series of oxygen and carbon isotopes as well as planktic Mg/Ca based thermometry from Site GeoB12615-4 in the western Indian Ocean. Our data suggest that SOIW transmitted Antarctic temperature trends to the equatorial Indian Ocean via the "oceanic tunnel" mechanism. Moreover, our results reveal that deglacial SOIW carried a signature of aged Southern Ocean deep water. We find no evidence of increased formation of intermediate waters during the deglaciation.