학술논문

Decadal-to-centennial increases of volcanic aerosols from Iceland challenge the concept of a Medieval Quiet Period
Document Type
article
Source
Communications Earth & Environment, Vol 5, Iss 1, Pp 1-18 (2024)
Subject
Geology
QE1-996.5
Environmental sciences
GE1-350
Language
English
ISSN
2662-4435
Abstract
Abstract Existing global volcanic radiative aerosol forcing estimates portray the period 700 to 1000 as volcanically quiescent, void of major volcanic eruptions. However, this disagrees with proximal Icelandic geological records and regional Greenland ice-core records of sulfate. Here, we use cryptotephra analyses, high-resolution sulfur isotope analyses, and glaciochemical volcanic tracers on an array of Greenland ice cores to characterise volcanic activity and climatically important sulfuric aerosols across the period 700 to 1000. We identify a prolonged episode of volcanic sulfur dioxide emissions (751–940) dominated by Icelandic volcanism, that we term the Icelandic Active Period. This period commences with the Hrafnkatla episode (751–763), which coincided with strong winter cooling anomalies across Europe. This study reveals an important contribution of prolonged volcanic sulfate emissions to the pre-industrial atmospheric aerosol burden, currently not considered in existing forcing estimates, and highlights the need for further research to disentangle their associated climate feedbacks.