Dendrochronology
The scientific discipline of dating annual tree rings to reconstruct past local climate conditions and calendar dates.
Governing formula
Tree Ring Width w = f(Temperature, Precipitation, Soil Moisture)
SI unit
Annual Calendar Years
In depth
Trees produce wide growth rings during favorable wet/warm years and narrow rings during drought or cold years. Cross-dating overlapping living and dead timber ring patterns creates continuous climate chronologies extending back over 10,000 years.
Examples in the real world
Using bristlecone pine tree-ring chronologies in the American Southwest to calibrate radiocarbon dating curves.