Black carbon concentrations and fluxes since the Last Glacial Maximum in Greenland and Antarctic ice cores
Warming from increased carbon dioxide and other greenhouse gas concentrations is the long-term driver of climate change but short-lived aerosols such as black carbon (BC) and continental dust also are important components of climate forcing. BC and dust in snow are especially important in the high latitudes because of their strong impact on albedo. With their short lifetimes in the atmosphere, aerosol concentrations and deposition rates are dominated by regional – rather than global – sources and intra- and inter-annual variability is high. Because most dust and BC aerosols in high latitudes originate in lower latitudes, changes in long range transport processes and pathways may dominate over changes in source strength in determining concentrations and deposition rates in the Polar Regions. However, detailed understanding of past and present concentrations, deposition rates, sources, and transport pathways of BC and dust is lacking. Here we present and discuss detailed measurements of BC, dust, and related source tracers in the WAIS Divide and NEEM deep ice cores. Our records at both sites extend from the Last Glacial Maximum to the Early Holocene and also span the last two millennia. Similar measurements in a Taylor Glacier horizontal core and section of GISP2, as well as in a broad array of Greenland and Antarctic cores spanning recent centuries to decades, help elucidate spatial variability within each region during the last glacial to interglacial transition and recent past, respectively.