Australia: The Land Where Time Began

A biography of the Australian continent 

Southern Ocean - Upwelling Driven by Wind and the Rise of Atmospheric CO₂ During Deglaciation

In the Southern Ocean around Antarctica wind-driven upwelling contributes to the regulation of CO₂ exchange between the atmosphere and the deep sea, as well as the dissolved silicon supply to the photic zone in the Southern Ocean. To the south of the Antarctic Polar Front the productivity of diatoms and the subsequent biogenic opal burial into the underlying sediments are limited by the supply of silicon. In this paper the authors¹ show that the rates of burial of opal, and therefore upwelling, were enhanced in each sector of the Southern Ocean during the last ice age termination. They found evidence of 2 intervals of upwelling that were concurrent with 2 intervals during which CO₂ concentrations in the atmosphere were rising during deglaciation, in the record with the greatest temporal resolution. The direct link between increased deep water ventilation and the  deglacial rise of atmospheric CO₂ has been shown by these results.

Sources & Further reading

1. Anderson, R. F., S. Ali, L. I. Bradtmiller, S. H. H. Nielsen, M. Q. Fleisher, B. E. Anderson, and L. H. Burckle. "Wind-Driven Upwelling in the Southern Ocean and the Deglacial Rise in Atmospheric Co2." Science 323, no. 5920 (March 13, 2009 2009): 1443-48.