Authors: Julie Edwards*, University of Arizona, Kevin Anchukaitis, University of Arizona, Laia Andreu-Hayles, Lamont-Doherty Earth Observatory, Rose Oelkers, Lamont-Doherty Earth Observatory, Rosanne D’Arrigo, Lamont-Doherty Earth Observatory, Georg von Arx, WSL Swiss Federal Institute for Forest, Snow and Landscape Research
Topics: Paleoenvironmental Change, Polar Regions, Earth Science
Keywords: Arctic, volcanic eruption, quantitative wood anatomy
Session Type: Paper
Presentation File: No File Uploaded
The 1783 Laki eruption in Iceland had a profound and measurable effect on climate in Europe. Early meteorological and historical records indicate that there was an annual mean cooling of 1-2 degrees Celsius below average following the eruption, but the seasonal and regional climate response were heterogeneous in space and time. In North America, tree-ring width and maximum latewood density chronologies from Alaska indicate that the summer of 1783 was anomalously cold, while in the eastern United States and around the North Atlantic historical sources describe the subsequent winter of 1783-1784 as particularly severe. In order to resolve the spatial extent and seasonal timing of the climate effects of the Laki eruption, we use a quantitative wood anatomy approach to examine if the reconstructed temperatures in Alaska during the 1783 summer were the result of late summer volcanic forcing. We measured wood anatomical characteristics including cell lumen area and cell wall thickness of white spruce trees from two locations in northern Alaska. Cell characteristics in the earlywood of the 1783 ring appear normal while latewood cell wall thickness in 1783 is significantly reduced compared to non-volcanic years. The thin latewood cell walls in 1783 indicate a rapid and premature cessation of the lignification process due to an abrupt decrease in temperature. These results demonstrate that wood anatomy can be a useful proxy for detecting the timing and seasonal climate fingerprint of volcanic events in tree-ring records worldwide.