Authors: Julie Edwards*, School of Geography, Development, and Environment, University of Arizona, Tucson, AZ, Laboratory of Tree-Ring Research, University of Arizona, Tucson, AZ, Kevin Anchukaitis, School of Geography, Development, and Environment, University of Arizona, Tucson, AZ, Laboratory of Tree-Ring Research, University of Arizona, Tucson, AZ, Brian Zambri, Department of Earth, Atmospheric, and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, MA, Laia Andreu-Hayles, Tree-Ring Laboratory, Lamont-Doherty Earth Observatory of Columbia University, Palisades, NY, Rose Oelkers, Tree-Ring Laboratory, Lamont-Doherty Earth Observatory of Columbia University, Palisades, NY, Rosanne D'Arrigo, Tree-Ring Laboratory, Lamont-Doherty Earth Observatory of Columbia University, Palisades, NY, Georg von Arx, Swiss Federal Institute for Forest Snow and Landscape Research WSL, Birmensdorf Switzerland, Hans Linderholm, Department of Earth Sciences, University of Gothenburg, Gothenburg, Sweden, Björn Gunnarson, Department of Physical Geography, Stockholm University, Stockholm, Sweden
Topics: Physical Geography, Paleoenvironmental Change, Climatology and Meteorology
Keywords: Dendrochronology, volcanic eruption, MXD, quantitative wood anatomy, climate
Session Type: Virtual Paper
Start / End Time: 3:05 PM / 4:20 PM
Room: Virtual 30
Presentation File: No File Uploaded
The 1783-1784 CE Laki eruption in Iceland was one of the largest high-latitude eruptions in the last millennium, but the seasonal and regional climate response was heterogeneous in space and time. Historical records in Europe show that the summer of 1783 was anomalously warm, but tree-ring maximum latewood density (MXD) data indicate low summer temperatures. In contrast, MXD reconstructions from Alaska suggest that the entire 1783 summer was extraordinarily cold, even though the Icelandic eruption only began in June. To resolve the intra-annual climate effects of the Laki eruption across spatially distant locations we measured wood anatomical characteristics of white spruce (Picea glauca) trees from two northern Alaska sites and Scots pine (Pinus sylvestris) from Jamtland, Sweden. Combined with complementary evidence from climate model experiments and proxy systems modeling, intra-annual cell characteristics indicate an abrupt and premature cessation of cell wall thickening due to a rapid temperature decrease toward the end of the growing season in Alaska. In the Swedish Scots pine, differences between the high-resolution and low-resolution anatomical MXD chronologies, along with the presence of intra-annual density fluctuations in many 1783 growth rings suggest acid damage to vegetation and/or a late summer transient cold period. Our study has implications not only for the interpretation of the climatic impacts of the Laki eruption in North America and Europe, but more broadly demonstrates the importance of proxy resolution, timing, and internal variability when comparing proxy temperature reconstructions and climate model simulations.