Glacier ice in polar and alpine regions acts as a natural environmental sampler, preserving atmospheric dust and other particulates through time. To learn about the sources of dust to the polar ice sheets, the project team will use a technique called isotopic fingerprinting. They will apply this approach to dust samples isolated from ice cores, which are cylinders drilled through a glacier or ice sheet, and which represent an important archive of Earth’s climate system. They will also measure the grain size distribution and concentration of the dust particles. Together with the isotopic fingerprints, these analyses will allow them to infer the source and transport pathway of the dust at different times in the past to improve understanding of past atmospheric circulation. They will apply this approach to ice core samples from several sites in Greenland and Antarctica. Determination of dust source, or provenance, through compositional analysis is a powerful approach for understanding Earth surface processes and changes in the Earth’s climate system. Previous work has shown that paired measurements of dust particle concentration and grain size distribution represent an important complement to geochemical analyses, allowing simultaneous assessment of changing source inputs and transport intensity to remote ice core locations. Development of provenance and grain size datasets on ice core dust from Greenland and Antarctica will enable the project team to test a range of hypothes