8000 years of North Atlantic storminess reconstructed from a Scottish peat record: implications for Holocene atmospheric circulation patterns in Western Europe

North Atlantic storminess can affect human settlements, infrastructure and transport links, all of which strongly impact local, national and global economies. An increase in storm frequency and intensity is predicted over the Northeast Atlantic in the 21st century because of a northward shift in storm tracks and a persistently positive North Atlantic Oscillation (NAO), driven by recent atmospheric warming. Although documentary records of North Atlantic storminess exist, these are generally limited to the last c. 1000‐2000 years. This paper presents a continuous high‐resolution proxy record of storminess spanning the last 8000 years from a 6 m long core taken from a peat bog in Northern Scotland. Bromine concentrations in the peat, derived from sea spray, are used to reconstruct storm frequency and storm intensity, and mire surface wetness is used as an indicator of longer‐term climate shifts. The results suggest a relationship between positive phases of the NAO and increased North Atlantic storminess. However, subtle differences between bromine concentrations and mire surface wetness suggest that high intensity but perhaps less frequent periods of storminess are not necessarily associated with a wetter climate

Supplementary information files for Increased North Atlantic dust deposition linked to Holocene Icelandic glacier fluctuations

Supplementary files for article Increased North Atlantic dust deposition linked to Holocene Icelandic glacier fluctuationsMineral dust concentrations are coupled to climate over glacial-interglacial cycles with increased dust deposition occurring during major cold phases over the last ~100 ka. Holocene records suggest considerable spatial and temporal variability in the magnitude, frequency and timing of dust peaks that reflects regional or local drivers of dust emissions and transport. Here, we present stratigraphical, geochemical and isotopic evidence for dust deposition from two high-resolution peat sequences 200 km apart in northern Scotland spanning the last c. 8200 years. εNd isotope data suggest the dominant minerogenic dust source switches between a low latitude (likely Saharan) and a high latitude, Icelandic source. Marked peaks in increased minerogenic dust deposition at: c. 5.4–5.1, 4.0–3.9, 2.8–2.6, 1.0 and 0.3 ka BP occur against a backdrop of low dust deposition during the mid-Holocene (c. 5.0–4.0 ka BP) and increased background levels of dust during the neoglacial period (<4.0 ka BP). These dust peaks coincide with periods of glacial advance in Iceland and heightened storminess in the North Atlantic. Isotope data for additional dust peaks at c. 1.0 and 0.7 ka BP and the last ~50 years suggest these reflect increased dust from the Sahara associated with aridity and land-use change in North Africa during the Late-Holocene, and modern anthropogenic sources. This work highlights the complexity of Holocene records of dust deposition in the North Atlantic and emphasises the role of dynamic sub-Polar glaciers and their meltwater systems as a significant dust source.</p

Increased North Atlantic dust deposition linked to Holocene Icelandic glacier fluctuations

Mineral dust concentrations are coupled to climate over glacialinterglacial cycles with increased dust deposition occurring during major cold phases over the last ~100 ka. Holocene records suggest considerable spatial and temporal variability in the magnitude, frequency and timing of dust peaks that reflects regional or local drivers of dust emissions and transport. Here, we present stratigraphical, geochemical, and isotopic evidence for dust deposition from two high-resolution peat sequences 200 km apart in northern Scotland spanning the last c. 8200 years. εNd isotope data suggest the dominant minerogenic dust source switches between a low latitude (likely Saharan) and a high latitude, Icelandic source. Marked peaks in increased minerogenic dust deposition at: c. 5.4-5.1 ka BP, c. 4.0-3.9 ka BP, c. 2.8-2.6 ka BP, c. 1.0 ka BP and c. 0.3 ka BP occur against a backdrop of low dust deposition during the mid-Holocene (c. 5.0–4.0 ka BP) and increased background levels of dust during the neoglacial period (<4.0 ka BP). These dust peaks coincide with periods of glacial advance in Iceland and heightened storminess in the North Atlantic. Isotope data for additional dust peaks at c. 1.0 ka BP, c. 0.7 ka BP and the last ~50 years suggest these reflect increased dust from the Sahara associated with aridity and land-use change in North Africa during the late Holocene, and modern anthropogenic sources. This work highlights the complexity of Holocene records of dust deposition in the North Atlantic and emphasizes the role of dynamic sub-Polar glaciers and their meltwater systems as a significant dust source.</p