PALEOFIRE · Developing a 4000-year East African fire history from the Kilimanjaro ice core

Tropical savanna fires currently comprise approximately two thirds of the global fire budget, making these fires a dominant factor in global carbon emissions, yet little is known how fires have varied through time. This project aims to create a fire history of the East African savanna region over the past 4000 years through the direct determination of levoglucosan in the Kilimanjaro ice core (3º04’S; 37º21’E; 5893 masl, 49 m depth). Levoglucosan is an atmospherically stable molecular tracer of biomass burning which does not degrade when deposited on ice surfaces and is an ideal proxy for quantifying fire activity. The host organization has developed an original method for measuring low concentrations (pg/mL) of levoglucosan in Antarctic ice samples using high-performance liquid chromatography/ electrospray ionization triple quadrupole mass spectrometry. Preliminary analyses on the Kilimanjaro core demonstrated the repeatability and applicability of the technique for tropical glacier ice. A history of fire emissions provides insight into changes in climate, vegetation, and human impacts. Savanna fires tend to be small and numerous which diminishes the likelihood that a single fire event will skew centennial variability and instead the record responds to major climate trends. The impacts of recent pollution emissions will be investigated through measuring anthropogenic atmospheric particular matter including polycyclic aromatic hydrocarbons (PAHs) and heavy metals in the Kilimanjaro ice for the past 200 yrs. Future climate projections suggest increased aridity in the African savanna region which highlights the necessity of understanding past fire activity to place present variability into perspective. The research will increase international cooperation through integrating a novel technique developed in a world-class laboratory with the only existing African ice core to provide a climate record with direct implications for the global carbon cycle.