Lapland 1,600 Year Tree-Ring Carbon Isotope Data Helama, S.; Arppe, L.; Uusitalo, J.; Holopainen, J.; Mäkelä, H.M.; Mäkinen, H.; Mielikäinen, K.; Nöjd, P.; Sutinen, R.; Taavitsainen, J.-P.; Timonen, M.; Oinonen, M. Helama, S. Arppe, L. Uusitalo, J. Holopainen, J. Mäkelä, H.M. Mäkinen, H. Mielikäinen, K. Nöjd, P. Sutinen, R. Taavitsainen, J.-P. Timonen, M. Oinonen, M. earth science/paleoclimate/tree ring (delta 13C,cellulose,null,per mil,annual,tree ring,null,isotope ratio mass spectrometry,N,units multiplied by 100) earth science/paleoclimate/tree ring (age,null,null,year Common Era,null,tree ring,null,null,N,null) earth science/paleoclimate/tree ring (sample identification,null,null,null,null,tree ring,null,null,N,core ID) earth science/paleoclimate/tree ring (delta 13C,cellulose,null,per mil,annual,tree ring,null,isotope ratio mass spectrometry,N,null) earth science/paleoclimate/tree-ring (Lapland>LATITUDE >LONGITUDE ) The large volcanic eruptions of AD 536 and 540 led to climate cooling and contributed to hardships of Late Antiquity societies throughout Eurasia, and triggered a major environmental event in the historical Roman Empire. Our set of stable carbon isotope records from subfossil tree rings demonstrates a strong negative excursion in AD 536 and 541-544. Modern data from these sites show that carbon isotope variations are driven by solar radiation. A model based on sixth century isotopes reconstruct an irradiance anomaly for AD 536 and 541-544 of nearly three standard deviations below the mean value based on modern data. This anomaly can be explained by a volcanic dust veil reducing solar radiation and thus primary production threatening food security over a multitude of years. We offer a hypothesis that persistently low irradiance contributed to remarkably simultaneous outbreaks of famine and Justinianic plague in the eastern Roman Empire with adverse effects on crop production and photosynthesis of the vitamin D in human skin and thus, collectively, human health. Our results provide a hitherto unstudied proxy for exploring the mechanisms of 'volcanic summers' to demonstrate the post-eruption deficiencies in sunlight and to explain the human consequences during such calamity years. STUDY NOTES: A discontinuous tree-ring d13C chronology has been developed from living and subfossil scots pine (Pinus sylvestris; PISY) samples for Lapland. Data include d13C series from five living trees and five subfossil trunks. IITRDB32 NCDC-Paleoclimatology https://www.ncdc.noaa.gov/data-access/paleoclimatology-data - Bauer Bruce Investigator : Helama, S. Investigator : Arppe, L. Investigator : Uusitalo, J. Investigator : Holopainen, J. Investigator : Mäkelä, H.M. Investigator : Mäkinen, H. Investigator : Mielikäinen, K. Investigator : Nöjd, P. Investigator : Sutinen, R. Investigator : Taavitsainen, J.-P. Investigator : Timonen, M. Investigator : Oinonen, M. 2018-01-22 ONLINE Files online, ASCII https://www.ncdc.noaa.gov/paleo/study/23374 https://www1.ncdc.noaa.gov/pub/data/paleo/treering/isotope/europe/finland/lapland2018d13c.rwl https://www1.ncdc.noaa.gov/pub/data/paleo/treering/isotope/europe/finland/lapland2018d13c.txt https://www1.ncdc.noaa.gov/pub/data/paleo/treering/isotope/europe/finland/lapland2018d13c.rwl https://www1.ncdc.noaa.gov/pub/data/paleo/treering/isotope/europe/finland/lapland2018d13c.txt English https://www.ncdc.noaa.gov/paleo/study/23374 https://www1.ncdc.noaa.gov/pub/data/paleo/treering/isotope/europe/finland/lapland2018d13c.rwl https://www1.ncdc.noaa.gov/pub/data/paleo/treering/isotope/europe/finland/lapland2018d13c.txt Samuli Helama, Laura Arppe, Joonas Uusitalo, Jari Holopainen, Hanna M. Mäkelä, Harri Mäkinen, Kari Mielikäinen, Pekka Nöjd, Raimo Sutinen, Jussi-Pekka Taavitsainen, Mauri Timonen, Markku Oinonen2018Volcanic dust veils from sixth century tree-ring isotopes linked to reduced irradiance, primary production and human healthScientific Reports1339810.1038/s41598-018-19760-whttps://www.nature.com/articles/s41598-018-19760-w Samuli Helama, Laura Arppe, Joonas Uusitalo, Hanna M. Mäkelä, Markku Oinonen, and Kari Mielikäinen2016Coexisting responses in tree-ring d13C to high-latitude climate variability under elevated CO2: A critical examination of climatic effects and systematic discrimination rate changesAgricultural and Forest Meteorology226-227199-21210.1016/j.agrformet.2016.06.005https://www.sciencedirect.com/science/article/pii/S0168192316303021 START YEAR: 415 AD * END YEAR: 2012 AD 22 68.4 28 68.5