BOREAUSTRALIS - Resolving troubling discord in Boreal versus Austral late Holocene temperature history
Short description
The growth rings of a tree tell the story of how the Earth's climate has varied over hundreds of years. According to temperature reconstructions based on natural climate proxy archives such as ice cores, lake sediments and tree rings, Northern and Southern Hemisphere temperature histories differ in important features over the past millennia. This stands in contrast to the broad hemispheric agreement found in corresponding climate model simulations. This project uses a new tree-ring proxy, based on quantitative wood anatomy, to improve temperature reconstructions in both hemispheres, and by this reduce differences between reconstructions and simulations. These advances are novel and highly relevant to communities engaged in climate modelling, climate reconstructions, and human history research.
The project is divided into the following aims:
- Create Boreal and Austral networks of quantitative wood anatomy data from tree rings from already sampled, as well as newly sampled trees growing in extra-tropical regions.
- Use the new proxy data to examine volcanic-related responses specifically in the SH, where model simulations and existing proxy reconstructions clearly disagree.
- Investigate if intra- and inter-hemispheric patterns of long-term temperature changes are more coherent among the new proxy records, and less different from corresponding model simulations.
