Identification of Arctic transport potential within the Northern Hemisphere based on an analysis of trajectories, 1979-2009

Abstract:

Black carbon is the optically dark component of particulate matter and results from both anthropogenic and natural combustion, including biomass combustion during wildland fire. Recent studies have shown that the deposition of black carbon (BC) is a significant contributor to observed warming trends in the Arctic. We examine the ability of the atmosphere to transport emissions to the Arctic from source locations across the Northern Hemisphere, creating a measure of Arctic transport potential. When Arctic transport potential is low, the ability of the atmosphere to transport emissions, including black carbon, to the Arctic quickly is reduced, and the likelihood of the emissions source creating a large impact on the Arctic is reduced. Using the Hybrid Single-Particle Lagrangian Integrated Trajectory (HYSPLIT) model along with global reanalysis and regional reanalysis data sets, trajectories were released at 7 source heights every 6 hours for the period 1979-2009 and tracked to see when they reached the arctic. An altas of Arctic transport potential was then developed using the results of the ~1B trajectories that shows the spatial patterns and variation in the number of trajectories reaching the Arctic within a threshold time period (selectable from 1-10 days) as a function of seasonality and starting height. By combining these results with estimated emissions sources, here done for wildland fire emissions, critical source areas and seasonal timings can be identified for further study or mitigation. Additionally, a daily prediction tool was created to indicate those periods when emissions are less likely to reach the Arctic. This tool, done as a prototype, offers the potential that managers, such as prescribed burners, may be able to better choose when burn in order to help mitigate potential impacts on the Arctic.