North Atlantic Climate Reconstruction during a Warm Event
from the Last Glacial Revealed through Geochemical
Analysis of a Scottish Flowstone.

Abstract

Dansgaard-Oeschger (DO) warm events were interstadial intervals during the last glacial
period characterised by abrupt increases in Northern Hemisphere temperature above
background glacial conditions, followed by a gradual return to a stadial state. The
mechanisms driving these rapid warming events, their spatial extent, and their influence on
global climate cycles remain a focus of current research. Developing a clearer understanding
of the triggers and controls of past climate states is critical for improving interpretations of
contemporary forcing mechanisms and their cascading impacts on climate variability. This
research presents new evidence for DO-12 warming at higher latitudes than previously
recognised, based on a new flowstone chronology from Scotland. This chronology aligns well
with SIOC19, supporting its adoption as the dominant chronology for the last glacial period.
A novel method for reconstructing palaeotemperature and hydrological variability is
introduced, derived from the temperature dependency of DMg and the degree of Prior Calcite
Precipitation (PCP) occurring within the flowstone analogue. The reconstructed temperature
range is notably large, with one possible explanation being the presence of an alternative
subarctic climate regime in Scotland during DO-12. Spectral analysis of NAO-band cycles
identifies a potential dampened meridional temperature gradient and stronger subtropical
forcing during DO-12, attributed to northwards shifts in key Atlantic climate mechanisms.
Overall, the results of this study contribute to a refined understanding of DO-12, its timing
and spatial influence, the behaviour of the NAO under abrupt warming, and the resultant
impacts on European climate. More broadly, this research enhances knowledge of climate
cycle dynamics and the thresholds and cascade effects associated with rapid forcing changes,
providing new insight into how these processes manifested during the last glacial period.