Collaborative Research: Assessing the response of tropical temperature to global forcings since the Last Glacial Maximum

Dartmouth College, Hanover NH

Investigators

Abstract

The tropics are the heat engine of the planet and home to about 40% of the world's population. However, we know very little about how and why tropical climate has changed through time. This project will develop a temperature record in the Rwenzori Mountains of Uganda covering the last ice age to the present to improve the understanding of the mechanisms that cause tropical climate change and the role of the tropics in the global climate system. The Rwenzori Mountains are among the very few glaciated tropical areas where such long-term, objective data can be obtained. This project will utilize two different sources of climate information including: 1) surface exposure dating of glacial moraines (ridges that mark former glacial extents) and glacial modeling, and 2) chemical analyses of lake sediment cores. The project will entail fieldwork in Uganda to collect glacial moraine samples and lake sediment cores. It will evaluate how tropical African temperature changes relate to similar reconstructions in tropical South America, and how they correspond to changes in solar radiation, Greenland and Antarctic ice sheet extents, and atmospheric greenhouse gas concentrations. The project will advance the effort to learn how the global climate worked over the last approximately 20,000 years. This award is cofunded by the Paleo Perspectives on Climate Change Program and the Office of International Science and Engineering.