Sea level, nutrients, temperatures and ice sheets during gla
Sea level modulation of Nitrogen fixation during glacials
In this study we identified a link between the foram-bound-δ15N (FB-δ15N) and variations in sea level over time. FB-δ15N was used to reconstruct changes in Nitrogen fixation across glacial/interglacial cycles. The data showed that Nitrogen fixation, a process that supplies the ocean with essential bioavailable nitrogen, is coupled to sedimentary denitrification on continental shelves. In turn, sedimentary denitrification depends on sea level with reduced denitrification rates during glacials when sea level is low and the shelf areas are exposed to air.
Patagonian ice sheet changes
This study explores changes in the Patagonian ice sheet over the last 140'000 years. We show the connection between the sediment/meltwater release during cold phases and precipitation caused by enhanced westerly winds at the northwestern margin of the Patagonian ice sheet.
Migration of the Antarctic Circumpolar Current
This study provides biomarker-based evidence that the Antarctic Circumpolar Current's latitude fluctuations correlate with Earth's axial tilt and changes in atmospheric carbon dioxide levels during the last G/IG cycle.
Influences on mean ocean nitrate δ15N
This study shows that in addition to N2 fixation and denitrification, partial nitrate assimilation in the Southern Ocean drives the δ15N of both deep ocean nitrate and global mean ocean nitrate.