Lonnie Thompson Has Died. He Dodged Avalanches to Preserve Climate History.

Lonnie Thompson, a climate scientist who over five decades ventured more than 60 times into the planet’s most daunting highlands to collect and preserve samples of the melting mountain ice, becoming one of the first researchers to document the effects of global warming in real time, died on Monday at his home in Columbus, Ohio. He was 78. Ohio State University, where Dr. Thompson was a professor in the school of earth sciences, announced the death but did not provide a specific cause.

With his wife and fellow glaciologist, Ellen Mosley-Thompson, Dr. Thompson was an early leader in the study of tropical glaciers, which sit on high peaks in the world’s warmest regions. Early in his career, most researchers believed those glaciers were of little scientific interest. In Greenland and Antarctica, the ice was hundreds of thousands of years old. By analyzing the dust, volcanic ash and air bubbles trapped inside, as well as the chemical properties of the water itself, scientists could decipher ancient swings in temperature, precipitation and atmospheric makeup.

The tropics, by contrast, were thought to be unwaveringly humid and rainy. And besides, tropical ice had presumably melted too much for it to be very old. Dr. Thompson’s work upended those ideas. Over the course of at least 66 expeditions, he and his colleagues hauled heavy equipment up mountains in South America, Africa, Asia and beyond. They camped on the ice for weeks at a time, drilling into the glaciers and pulling out cylindrical cores that could total hundreds of feet in length.

We are having trouble retrieving the article content. Please enable JavaScript in your browser settings. Thank you for your patience while we verify access. If you are in Reader mode please exit and log into your Times account, or subscribe for all of The Times. Thank you for your patience while we verify access. Already a subscriber? Log in . Want all of The Times? Subscribe .