Linda Sohl

Linda posing in South Australia with roughly 100 million years of Earth history between herself and the hills on the horizon - including glacial rocks deposited in the tropics.

Linda Sohl is an earth systems scientist at NASA's Goddard Institute for Space Studies and Columbia University's Center for Climate Systems Research. As a young girl growing up in the Bronx, she spent hours with a guide to rocks and minerals in one hand and a bunch of pebbles in the other, trying to figure out what the last ice age had left behind in her backyard. Though she received a B.A. in communications from Fordham University in 1987, the siren call of the earth sciences was irresistible; she went on to earn a B.A. in geology from Hunter College of the City University of New York in 1993, and a Ph.D. in earth and environmental sciences from Columbia University's Lamont-Doherty Earth Observatory in 2000.

While Dr. Sohl was still a grad student, she became fascinated by a controversial hypothesis: the Earth's climate had at one time, more than 600 million years ago, been so cold that continent-sized ice sheets were able to exist in the tropics. As luck would have it, she was already doing fieldwork in Australia, close to glacial rocks that would let her test this hypothesis in detail. Using a technique called paleomagnetic analysis, which measures the orientation of tiny magnetic grains within rocks, she was able to show that certain glacial rocks in Australia were deposited at roughly the same latitude as modern-day Costa Rica or Thailand - meaning the Earth had gotten very cold indeed!

The thrill of being able to show that Earth's climate had been so extreme in the past raised the inevitable questions: How could such a thing have ever happened, and how did we escape being forever stuck in a deep freeze? The search for answers led Dr. Sohl into the world of climate modeling, where it is possible to explore the processes that create and influence extreme climates in a way that geologic data alone cannot. Dr. Sohl's research interests have since broadened into further applications of climate models and how they can be used together with data to deepen our understanding of Earth's climate system - how it has responded throughout Earth history, and may respond again in the future, to extreme changes in climate forcings. She also hopes someday to take lessons learned from Earth and apply them to terrestrial-like planets in other solar systems. Dr. Sohl is a member of the American Geophysical Union and the Geological Society of America.