The last interglacial is a warm period that could provide insights into future warm conditions. Here, we compile and analyse carbon isotope data from the ocean during the last interglacial compared to the mid-Holocene. The data show that Atlantic Ocean circulation was similar during these periods. We also establish a mean oceanic carbon isotope difference between these periods which was most likely caused by burial and weathering carbon fluxes.
The last interglacial is a warm period that could provide insights into future warm conditions....
Review status: a revised version of this preprint was accepted for the journal CP and is expected to appear here in due course.
Lower oceanic ๐ฟ13C during the Last Interglacial compared to the Holocene
Shannon A. Bengtson1,2,Laurie C. Menviel1,Katrin J. Meissner1,2,Lise Missiaen1,Carlye D. Peterson3,Lorraine E. Lisiecki4,and Fortunat Joos5,6Shannon A. Bengtson et al.Shannon A. Bengtson1,2,Laurie C. Menviel1,Katrin J. Meissner1,2,Lise Missiaen1,Carlye D. Peterson3,Lorraine E. Lisiecki4,and Fortunat Joos5,6
Received: 20 May 2020 – Accepted for review: 06 Jun 2020 – Discussion started: 11 Jun 2020
Abstract. The last time in Earthโs history when the high latitudes were warmer than during pre-industrial times was the last interglacial (LIG, 129–116 ka BP). Since the LIG is the most recent and best documented warm time period, it can provide insights into climate processes in a warmer world. However, some key features of the LIG are not well constrained, notably the oceanic circulation and the global carbon cycle. Here, we use a new database of LIG benthic ๐ฟ13C to investigate these two aspects. We find that the oceanic mean ๐ฟ13C was ~ 0.2 โฐ lower during the LIG (here defined as 125–120 ka BP) when compared to the mid-Holocene (7–4 ka BP). As the LIG was slightly warmer than the Holocene, it is possible that terrestrial carbon was lower, which would have led to both a lower oceanic ๐ฟ13C and atmospheric ๐ฟ13CO2 as observed in paleo-records. However, given the multi-millennial timescale, the lower oceanic ๐ฟ13C most likely reflects a long-term imbalance between weathering and burial of carbon. The ๐ฟ13C distribution in the Atlantic Ocean suggests no significant difference in the latitudinal and depth extent of North Atlantic Deep Water (NADW) between the LIG and the mid-Holocene. Furthermore, the data suggests that the multi-millennial mean NADW transport was similar between these two time periods.
The last interglacial is a warm period that could provide insights into future warm conditions. Here, we compile and analyse carbon isotope data from the ocean during the last interglacial compared to the mid-Holocene. The data show that Atlantic Ocean circulation was similar during these periods. We also establish a mean oceanic carbon isotope difference between these periods which was most likely caused by burial and weathering carbon fluxes.
The last interglacial is a warm period that could provide insights into future warm conditions....