High sensitivity of summer temperatures to stratospheric sulfur loading from volcanoes in the Northern Hemisphere

• Published in: Proceedings of the National Academy of Sciences
• Main Authors: Burke, Andrea, Crick, Laura, Anchukaitis, Kevin J., Innes, Helen, Byrne, Michael P., Hutchison, William, McConnell, Joseph R., Moore, Kathryn A., Rae, James W. B., Sigl, Michael, Wilson, Rob
• Other Authors: European Commission, The Leverhulme Trust, Medical Research Council, University of St Andrews. School of Earth & Environmental Sciences, University of St Andrews. St Andrews Isotope Geochemistry, University of St Andrews. Centre for Energy Ethics, University of St Andrews. St Andrews Sustainability Institute
• Format: Article in Journal/Newspaper
• Language: English
• Published: 2023
• Subjects: Volcanoes; Climate; Ice cores; Sulfur isotopes; GE Environmental Sciences; DAS; GE; Antarctic; Greenland; Antarc*; ice core; Sea ice
• Online Access: http://hdl.handle.net/10023/28665; https://doi.org/10.1073/pnas.2221810120

This work was funded by an ERC (European Research Council) Marie Curie Career Integration Grant (CIG14-631752) and a Philip Leverhulme prize in Earth Sciences (PLP-2021-167) from the Leverhulme Trust awarded to A.B. WH is funded by a UKRI Future Leaders Fellowship (MR/S033505/1). M.S. acknowledges the support of the ERC under the European Union’s Horizon 2020 research and innovation programme (grant agreement 820047). H.M.I. and L.C. were both funded by IAPETUS and IAPETUS2 NERC Doctoral Training Partnership. The Tunu2013 and NEEM_2011_S1 ice cores were collected and analyzed for sulfur and other chemical species used to establish the ice core chronologies with funding from NSF grants 1204176 and 0909541 to J.R.M., respectively, and ice cores were sampled with funding from NSF grant 1340174. The 540s, 1450s, and 1600s represent three of the five coldest decades in the Common Era (CE). In each of these cases, the cause of these cold pulses has been attributed to large volcanic eruptions. However, the provenance of the eruption and magnitude of the volcanic forcing remains uncertain. Here, we use high-resolution sulfur isotopes in Greenland and Antarctic ice cores measured across these events to provide a means of improving sulfur loading estimates for these eruptions. In each case, the largest reconstructed tree-ring cooling is associated with an extratropical eruption, and the high-altitude stratospheric sulfate loading of these events is substantially smaller than previous estimates (by up to a factor of two). These results suggest an increased sensitivity of the reconstructed Northern Hemisphere summer temperature response to extratropical eruptions. This highlights the importance of climate feedbacks and processes that amplify and prolong the cooling signal from high latitudes, such as changes in sea ice extent and ocean heat content. Publisher PDF Peer reviewed