scholarly journals Re-evaluating the link between the Laacher See volcanic eruption and the Younger Dryas

2017 ◽  
Author(s):  
James U. L. Baldini ◽  
Richard J. Brown ◽  
Natasha Mawdsley
Keyword(s):  
North Atlantic ◽  
Volcanic Eruption ◽  
Ice Core ◽  
Younger Dryas ◽  
Oceanic Circulation ◽  
Sulphate Aerosol ◽  
Atlantic Region ◽  
Ice Volume ◽  
The North ◽  
The North Atlantic

Abstract. The Younger Dryas is the most well-documented millennial-scale cooling event of the Quaternary, but the mechanisms responsible for its initiation remain elusive. Here we use a recently revised chronology for the GISP2 ice core ion dataset to identify a large volcanic sulphur spike coincident with both the sulphur-rich Laacher See volcanic eruption and the onset of Younger Dryas-related cooling (GS-1) in Greenland. Lake sediment and stalagmite records confirm that the eruption's timing was indistinguishable from the onset of cooling across the North Atlantic, but that it preceded westerly wind repositioning over central Europe by ~ 200 years. We suggest that the initial short-lived volcanic sulphate aerosol cooling was amplified by oceanic circulation shifts or sea ice expansion, gradually cooling the North Atlantic region and incrementally shifting the mid-latitude westerlies to the south. The aerosol-related cooling probably only lasted 2–4 years, and the majority of Younger Dryas-related cooling was instead due to this positive feedback, which was particularly effective during the intermediate ice volume conditions characteristic of ~ 13 ka BP. We conclude that the large and sulphur-rich Laacher See eruption should be considered a viable trigger for the Younger Dryas.

Data-model comparison of the Younger Dryas event

2000 ◽  
Vol 37 (5) ◽  
pp. 811-830 ◽  
Author(s):  
Nathaniel W Rutter ◽  
Andrew J Weaver ◽  
Dean Rokosh ◽  
Augustus F Fanning ◽  
Daniel G Wright
Keyword(s):  
North Atlantic ◽  
General Circulation ◽  
Younger Dryas ◽  
North Atlantic Region ◽  
Atlantic Region ◽  
Climate Proxy ◽  
Proxy Records ◽  
The North ◽  
The North Atlantic ◽  
Younger Dryas Event

The Younger Dryas cooling event is well established in the North Atlantic region through numerous climate proxy records. Although the climatological controls vary from site to site, it is considered to have taken place between about 10 000 and 11 000 BP (radiocarbon years) (~11 500-13 000 calendar years ago). Outside the North Atlantic region, climate proxy records and chronology commonly become problematic because of weaker signals and less dating control. In addition to this evidence, oceanic records reveal conflicting evidence for Younger Dryas forcing mechanisms and the timing of events. We compare proxy evidence with the results from an ocean general circulation model coupled to the energy-moisture balance atmospheric model. The model results reveal a global pattern and regional magnitude which generally agree with temperature changes interpreted from paleoclimate reconstructions. The model also supports the general duration of global cooling of the Younger Dryas. Although proxy data can be controversial outside of the North Atlantic region, the authors believe that there is enough evidence to support the Younger Dryas event on a global scale. They also recognize, however, that more concrete evidence is needed before the question can be unequivocally answered.

scholarly journals Evaluating the link between the sulfur-rich Laacher See volcanic eruption and the Younger Dryas climate anomaly

2018 ◽  
Vol 14 (7) ◽  
pp. 969-990 ◽  
Author(s):  
James U. L. Baldini ◽  
Richard J. Brown ◽  
Natasha Mawdsley
Keyword(s):  
Sea Ice ◽  
Ocean Circulation ◽  
North Atlantic ◽  
Ice Core ◽  
Younger Dryas ◽  
Greenland Ice Sheet ◽  
Climate Modelling ◽  
The North ◽  
The North Atlantic ◽  
Millennial Scale

Abstract. The Younger Dryas is considered the archetypal millennial-scale climate change event, and identifying its cause is fundamental for thoroughly understanding climate systematics during deglaciations. However, the mechanisms responsible for its initiation remain elusive, and both of the most researched triggers (a meltwater pulse or a bolide impact) are controversial. Here, we consider the problem from a different perspective and explore a hypothesis that Younger Dryas climate shifts were catalysed by the unusually sulfur-rich 12.880 ± 0.040 ka BP eruption of the Laacher See volcano (Germany). We use the most recent chronology for the GISP2 ice core ion dataset from the Greenland ice sheet to identify a large volcanic sulfur spike coincident with both the Laacher See eruption and the onset of Younger Dryas-related cooling in Greenland (i.e. the most recent abrupt Greenland millennial-scale cooling event, the Greenland Stadial 1, GS-1). Previously published lake sediment and stalagmite records confirm that the eruption's timing was indistinguishable from the onset of cooling across the North Atlantic but that it preceded westerly wind repositioning over central Europe by ∼ 200 years. We suggest that the initial short-lived volcanic sulfate aerosol cooling was amplified by ocean circulation shifts and/or sea ice expansion, gradually cooling the North Atlantic region and incrementally shifting the midlatitude westerlies to the south. The aerosol-related cooling probably only lasted 1–3 years, and the majority of Younger Dryas-related cooling may have been due to the sea-ice–ocean circulation positive feedback, which was particularly effective during the intermediate ice volume conditions characteristic of ∼ 13 ka BP. We conclude that the large and sulfur-rich Laacher See eruption should be considered a viable trigger for the Younger Dryas. However, future studies should prioritise climate modelling of high-latitude volcanism during deglacial boundary conditions in order to test the hypothesis proposed here.

scholarly journals The Younger Dryas Cold Event—Was It Synchronous Over the North Atlantic Region?

Radiocarbon ◽  
1995 ◽  
Vol 37 (1) ◽  
pp. 63-70 ◽  
Author(s):  
Tomasz Goślar ◽  
Maurice Arnold ◽  
Mieczysław F. Pazdur
Keyword(s):  
Lake Sediments ◽  
North Atlantic ◽  
Younger Dryas ◽  
Ice Cores ◽  
North Atlantic Region ◽  
Atlantic Region ◽  
Cold Event ◽  
The North ◽  
The North Atlantic ◽  
Exact Timing

Determined independently from annually laminated ice cores and lake sediments, and German pines, the calendar ages of Younger Dryas (YD) boundaries significantly disagree with one another. 14C dates, plotted vs. calendar ages for samples from different sediments, also reveal distinct offsets. The adjustment of varve chronologies to synchronize the boundaries of the YD nearly cancels the discrepancies between 14C data, and supports the synchronism of the YD cold period over the North Atlantic region. However, the exact timing of the event cannot be estimated in this way.

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