Petrified tree rings tell ancient tale of sun’s behavior
Variations in growth rate match today’s 11-year solar cycle, study claims
![tree rings](https://i0.wp.com/www.sciencenews.org/wp-content/uploads/2017/01/011317_TS_tree-ring_main.jpg?fit=860%2C460&ssl=1)
ANTIQUE RINGS The rings in trees buried by volcanic eruptions hundreds of millions of years ago show evidence of climate variations caused by the 11-year solar cycle, researchers report.
L. Luthardt and R. Rößler