Generating a 1.3-million-year history of temperature and rainfall in continental tropical East Africa

Extreme temperatures on land frequently occur, especially in the tropics. East Africa is particularly vulnerable because a large portion of the population relies on subsistence agriculture and the region has experienced dangerous heatwaves with consequences for human health, flooding/droughts, and famine, and associated implications for societal unrest, emigration, and regional security. Currently, the relationship between temperature and precipitation in East Africa is not well understood, and it is unknown if this region will become wetter or drier in the future. This project will examine a geological record to generate new long-term reconstructions of temperature and rainfall for East Africa, thereby providing the observations needed for future trends in temperature, rainfall and drought to be more reliably predicted, and offering a technical basis for water management programs. This project will train graduate and undergraduate students and provide summer workshops for middle and high school teachers, helping to strengthen U.S. STEM education and train the future STEM workforce. This study will apply organic geochemical and isotopic techniques to a previously collected drill core from Lake Malawi to generate reconstructions of temperature, precipitation and vegetation spanning the past 1.38 million years. These records will be examined in conjunction with existing data to investigate the roles of tectonic, oceanic and atmospheric forcings on East African temperature and rainfall variability on different timescales. Data produced by this study will provide information on the natural drivers of continental temperature and rainfall variability over a range of tectonic and environmental conditions, providing a particularly valuable dataset, unique for the African continent, to improve the next generation of atmospheric circulation models. Hands-on field, classroom and laboratory teaching activities developed during teacher training workshops will be made available online allowing educators anywhere to access and download these modules. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.