Two-phase change in CO2, Antarctic temperature and global climate during Termination II

TY - JOUR

T1 - Two-phase change in CO2, Antarctic temperature and global climate during Termination II

AU - Landais, A.

AU - Dreyfus, G.

AU - Capron, Emilie

AU - Jouzel, J.

AU - Masson-Delmotte, Valérie

AU - Roche, D. M.

AU - Prié, Frédéric

AU - Caillon, N.

AU - Chappellaz, J.

AU - Leuenberger, H.N.

AU - Lourantou, A.

AU - Parrenin, F

AU - Raynaud, D

AU - Teste, G.

PY - 2013/12

Y1 - 2013/12

N2 - The end of the Last Glacial Maximum (Termination I), roughly 20 thousand years ago (ka), was marked by cooling in the Northern Hemisphere, a weakening of the Asian monsoon, a rise in atmospheric CO 2 concentrations and warming over Antarctica. The sequence of events associated with the previous glacial-interglacial transition (Termination II), roughly 136 ka, is less well constrained. Here we present high-resolution records of atmospheric CO 2 concentrations and isotopic composition of N 2 - an atmospheric temperature proxy - from air bubbles in the EPICA Dome C ice core that span Termination II. We find that atmospheric CO 2 concentrations and Antarctic temperature started increasing in phase around 136 ka, but in a second phase of Termination II, from 130.5 to 129 ka, the rise in atmospheric CO 2 concentrations lagged that of Antarctic temperature unequivocally. We suggest that during this second phase, the intensification of the low-latitude hydrological cycle resulted in the development of a CO 2 sink, which counteracted the CO 2 outgassing from the Southern Hemisphere oceans over this period.

AB - The end of the Last Glacial Maximum (Termination I), roughly 20 thousand years ago (ka), was marked by cooling in the Northern Hemisphere, a weakening of the Asian monsoon, a rise in atmospheric CO 2 concentrations and warming over Antarctica. The sequence of events associated with the previous glacial-interglacial transition (Termination II), roughly 136 ka, is less well constrained. Here we present high-resolution records of atmospheric CO 2 concentrations and isotopic composition of N 2 - an atmospheric temperature proxy - from air bubbles in the EPICA Dome C ice core that span Termination II. We find that atmospheric CO 2 concentrations and Antarctic temperature started increasing in phase around 136 ka, but in a second phase of Termination II, from 130.5 to 129 ka, the rise in atmospheric CO 2 concentrations lagged that of Antarctic temperature unequivocally. We suggest that during this second phase, the intensification of the low-latitude hydrological cycle resulted in the development of a CO 2 sink, which counteracted the CO 2 outgassing from the Southern Hemisphere oceans over this period.

U2 - 10.1038/ngeo1985

DO - 10.1038/ngeo1985

M3 - Journal article

SN - 1752-0894

VL - 6

SP - 1062

EP - 1065

JO - Nature Geoscience

JF - Nature Geoscience

ER -