Paleocirculation

The role of melting-ice in driving the slowdown of circulation in the western Atlantic Ocean revealed by protactinium-thorium ratio

Abrupt climate changes in the past have been attributed to variations in Atlantic Meridional Overturning Circulation (AMOC) strength. Knowing the exact timing and magnitude of the AMOC shift is important to understand the driving mechanism of such climate variability. After a thorough selection of 13 sediment cores, the authors show that the proxy Protactinium-231-Thorium-230 (231Pa/230Th) […]

Oct / 19 / 2018

Why did the concentration of atmospheric carbon dioxide rise so much and so quickly during the last deglaciation? 

During the Last Glacial Maximum, the deep southern Pacific waters were stratified, efficiently accumulating old, CO2 rich waters. Basak and co-authors (2018, see reference below) measured neodymium isotopes in sediment cores that clearly show that when these deep waters became less stratified as the climate warmed they released their carbon which could escape to the […]

Mar / 06 / 2018

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