The Map Hidden in the Pacific Northwest’s Tree Rings

A meteorologist can track a storm today using satellite or pulse-Doppler radar data. A weather historian can track a storm from a century ago using records—watching it crawl across the plains through the precipitation totals of yellowed farm journals and log books.

Now, two scientists may have found a way to track a storm—or, at least, track the average of all storms across the season—325 years in the past.

In a paper published this month in Science Advances, Erika Wise and Matthew Dannenberg, both paleoclimatologists at the University of North Carolina, teased three centuries of local climate history out of the ponderosa pine trees that dot the Pacific Northwest. Their finding will resonate beyond the Cascades: Because that region is so important to how moisture enters and fans across North America, the study helps answer important questions about how climate change will roil the United States.

At the center of the paper is an especially sensitive species nestled across an especially ecologically diverse