Timing and structure of the Younger Dryas event and its underlying climate dynamics

Abstract

The Younger Dryas (YD), arguably the most widely studied millennial-scale extreme climate event, was characterized by diverse hydroclimate shifts globally and severe cooling at high northern latitudes that abruptly punctuated the warming trend from the last glacial to the present interglacial. To date, a precise understanding of its trigger, propagation, and termination remains elusive. Here, we present speleothem oxygen-isotope data that, in concert with other proxy records, allow us to quantify the timing of the YD onset and termination at an unprecedented subcentennial temporal precision across the North Atlantic, Asian Monsoon-Westerlies, and South American Monsoon regions. Our analysis suggests that the onsets of YD in the North Atlantic (12,870 ± 30 B.P.) and the Asian Monsoon-Westerlies region are essentially synchronous within a few decades and lead the onset in Antarctica, implying a north-to-south climate signal propagation via both atmospheric (decadal-time scale) and oceanic (centennial-time scale) processes, similar to the Dansgaard–Oeschger events during the last glacial period. In contrast, the YD termination may have started first in Antarctica at ∼11,900 B.P., or perhaps even earlier in the western tropical Pacific, followed by the North Atlantic between ∼11,700 ± 40 and 11,610 ± 40 B.P. These observations suggest that the initial YD termination might have originated in the Southern Hemisphere and/or the tropical Pacific, indicating a Southern Hemisphere/tropics to North Atlantic–Asian Monsoon-Westerlies directionality of climatic recovery.

High precise dating on the variation of the Asian summer monsoon since 37 ka BP

“…In addition, the onset of YD in the North Atlantic, Greenland, and the Asian Monsoon region are synchronous within a few decades (Fig. 8 ) 62 . All the above mentioned observations suggest possible different mechanisms for the correlation between high and mid-low latitudes climate change at the different background of H events, and YD, D/O events.…”

Supplemental Material: Immediate temperature response in northern Iberia to last deglacial changes in the North Atlantic

“…Very few speleothem records are available for the last deglaciation interval in Europe. In Iberia, it is worth to highlight the record from Seso Cave in Central Pyrenees (Bartolomé et al, 2015; later improved by Cheng et al, 2020). The chronological control and high isotopic resolution of that record, in spite it only covers the GS-1 interval, indicates a high similarity with OST2 stalagmite (Fig.…”

“…. Detailed comparison of the δ 18 O records from Seso cave (Cheng et al, 2020) and the global ice volume corrected δ 18 O values of Ostolo cave (OST2) at the GS-1.…”

The 4.2 ka event in East Asian monsoon region, precisely reconstructed by multi-proxies of stalagmite

“…At present, most researches on stalagmites are based on stalagmite δ 18 O to reconstruct paleoclimate change (Cheng et al, 2009(Cheng et al, , 2020Kathayat et al, 2018;Tan et al, 2020). Liu et al (2015) and Chen et al (2016) compared the stalagmite δ 18 O records in the ASM region, indicating that the stalagmite δ 18 O records showed the consistent changes from Centennial to the orbital scale.…”