Changes in Arctic black carbon concentrations, deposition, transport, and sources during recent centuries

• Main Authors: McConnell, J. R., Dahl-Jensen, D., Flanner, M., Fritzsche, Diedrich, Kreutz, K., Lamarque, J. F., Lawrence, R., Maselli, O., Nolan, M., Opel, Thomas, Pasteris, D., Sigl, M., Steffensen, J. P.
• Format: Conference Object
• Language: unknown
• Published: 2011
• Subjects: albedo; Arctic; black carbon; Climate change
• Online Access: https://epic.awi.de/id/eprint/25171/; https://hdl.handle.net/10013/epic.38506

Rates of climate change in the Arctic are among the highest on Earth. Warming from increased carbon dioxide and other greenhouse gas concentrations is the long-term driver of Arctic climate change, but reductions in short-lived aerosols such as black carbon (BC) that contribute to climate warming offer the possibility of slowing Arctic climate change in the near-term. BC in snow and water is especially important to climate forcing in the Arctic because of its impact on albedo. Detailed understanding of past and present concentrations, deposition rates, sources, and transport pathways of BC to and within the Arctic is critical, however, to the design of effective mitigation policies. With their short lifetimes in the atmosphere, aerosol concentrations and deposition in the Arctic are dominated by regional, rather than global, sources, transport processes, and pathways. Such aerosols consist of continental dust, sea spray, particulates including BC and organic matter from combustion processes, sulfur and trace metals from volcanic emissions, and, during recent centuries, industrial activities. Further, intra- and inter-annual variability of aerosol deposition is large. As a result, spatially distributed measurements of historical, high-time-resolution records with a broad range of analytes are required to understand aerosol concentrations, sources, and variability while providing adequate information for evaluating global circulation, snowpack radiation, and other modeling results. Arrays of ice cores from polar and alpine glaciers and ice sheets offer the potential to provide spatially distributed historical records with very high time resolution and a broad spectrum of aerosols and source tracers, particularly when using a continuous flow analytical system. Here we present and discuss recent findings from measurements of BC and related source tracers in a developing array of ice cores from around the Arctic. We use 1850 to 2000 general circulation modeling to evaluate sources and transport pathways for BC, ...