Models use satellite data to calculate deforestation's impact on Kilimanjaro

University of Alabama in Huntsville Campus News: The impacts that local deforestation might have on the snowcap and glaciers atop Mount Kilimanjaro are being calculated at The University of Alabama in Huntsville using regional climate models and data from NASA satellites. The first piece of that research, which looked only at the month of July, found that deforestation is changing weather patterns around the mountain but not (at least in July) at the peak, according to Dr. Udaysankar Nair, a research scientist in UAHuntsville's Earth System Science Center.

Early results from this work, which is funded through NASA's Earth Science Directorate, were published Feb. 15 in the "Journal of Geophysical Research."

A tiny fraction of that ice cap still exists. Surveys in the 1880s estimated that glaciers covered about 20 square kilometers on the mountain. From 1912 to now, the glacier area on Kilimanjaro has decreased from 12 square kilometers to less than two. Nair and doctoral student Jonathan Fairman, a NASA Earth system science fellow, are studying the effects of deforestation on weather patterns in a 2,000-square-mile area around the mountain.

…"Kilimanjaro is an isolated mountain, so under normal circumstances most of the local air flow goes around the mountain," Nair said. "When you cut down forests you reduce surface roughness, which increases wind speed at higher elevations on the windward slopes. That faster wind over steep upper slopes causes more intense cloud formation and precipitation up the side of the mountain."

Nair and Fairman are extending their model runs to include the fall and spring rainy seasons, when the dominant weather rolls in from the Indian Ocean. "We need to look at the complete annual cycle before we understand the impacts that deforestation is having on the mountain peak," Fairman said.

Early results suggest that deforestation around Kilimanjaro might be having a noticeable impact on how quickly glaciers and ice are melting on the mountain, although it isn't clear from preliminary data modeling whether that impact is positive or negative….

The current glaciers of Kilimanjaro, made famous by an Ernest Hemingway short story in 1936 and a movie released in 1952, are almost 12,000 years old. About 16,000 years ago, during the most recent ice age, Kilimanjaro's glaciers covered up to 150 square kilometers and reached from the summit (19,298 feet above sea level) to the surrounding plain more than 9,000 feet below. Image from the website of the University of Alabama in Huntsville