The supra-long Scots pine tree-ring record for Finnish Lapland: Part 2, interannual to centennial variability in summer temperatures for 7500 years

• Published in: The Holocene
• Main Authors: Helama, Samuli, Lindholm, Markus, Timonen, Mauri, Meriläinen, Jouko, Eronen, Matti
• Format: Article in Journal/Newspaper
• Language: English
• Published: SAGE Publications 2002
• Subjects: Northern Finland; Lapland
• Online Access: http://dx.doi.org/10.1191/0959683602hl581rp; https://journals.sagepub.com/doi/pdf/10.1191/0959683602hl581rp

Midsummer (July) temperatures are reconstructed for the last 7500 years using the long ring-width chronology of Scots pine (Pinus sylvestris L.) from northern Finland. The chronology was built using regional curve standardization (RCS), which allows for long-term (low-frequency) variability to be extracted from this annually resolved record of 1087 samples from living trees and subfossil timber. Short-and long-term changes in reconstructed July temperatures are presented. The regression model accounts for 37% of the dependent instrumental temperature variance between ad 1879 and 1992. The warmest 30-year periods were ad 560–531, ad 560–531, 1190–1161 bc and ad 1541–1570, and the coldest 5240–5211, 5150–5121 and 3710–3681 bc. The warmest 100-year periods were ad 1501–1600, 600–501 bc and 300–201 bc, and the coldest 5200–5101, 2500–2401 and 1500–1401 bc. Broad comparisons are made with dendrochronological, lacustrine and glacial proxy evidence.