Maximum Latewood Density Analysis Solves Long‐Standing Mystery Between Temperature Reconstructions and Historical Records

Abstract

AbstractEdwards et al. (2022, https://doi.org/10.1029/2021pa004386) take tree ring samples from Scots pine trees in Sämtland, Sweden, and analyze them to reconstruct the summer temperatures for 1783. The maximum latewood density data for 1783 are low, suggesting cooler temperatures. The authors conclude that anatomical anomalies in their samples resulted from acidic damage caused by the Laki haze, a dry and sulfuric smelling fog emitted by the Laki fissure in Iceland during its eruption, which lasted from 8 June 1783 to 7 February 1784. This finding resolves a long‐standing discrepancy between historical documents that indicate an unusually warm summer in 1783 and temperature reconstructions based on tree rings that often suggested a cooler summer. The paper by Edwards et al. (2022, https://doi.org/10.1029/2021pa004386) thereby shows the potential of interdisciplinary collaborations: Only by studying historical records does it becomes apparent that the summer was not cold but warm. Historical records indicate further that the Laki haze also affected the vegetation in other parts of Europe, such as England, the Low Countries, and Germany. Further study of tree rings to reconstruct the temperature of other regions is desirable.