Biomass burning and fossil fuel combustion releases large amounts of carbon into the atmosphere that are changing Earth’s climate. Up to 27% and 0.2% of carbon from biomass burning and fossil fuel combustion, respectively, is retained as black carbon (BC), a byproduct from incomplete combustion, rather than emitted as greenhouse gases. In addition to affecting radiative budgets, BC also influences biogeochemical processes, and plays an key - yet currently poorly quantified - role in the global carbon cycle. Our understanding of the role of BC in the regional and global-scale carbon cycle is hindered in large part due to limited constraints on the riverine export and fate of BC in the ocean. Here, we use the Mackenzie River- Beaufort Sea system in the Arctic to assess the magnitude and nature of BC transfer across the river-to-ocean aquatic continuum.  We focus on this system due to the disproportionally large terrestrial influence on this semi-enclosed marine basin, and because of the rapid pace of change that this system is experiencing. We report the first high resolution production input of BC by fires on a regional level across 6 sub-basins of the Mackenzie River using the Arctic Boreal Vulnerability Experiment Fire Emissions Database (ABoVE-FED) and ratios of production to carbon emissions. We compile black carbon stocks and fluxes, D¹⁴C values, as well as qualitative information on BC composition across the entire aquatic continuum, with the goal of shedding new light on the dynamics of this important yet enigmatic component of the carbon cycle, as well as its sensitivity to, and influence on past and future environmental change.

Primary Presenter: Alysha Coppola, ETH Zurich (acoppola@ethz.ch)

Authors:

Alysha Coppola, Linnaeus University   (acoppola@ethz.ch)

Max van Gerrevink, Vrije Universiteit Amsterdam  (m.j.van.gerrevink@vu.nl)

Sander Veraverbeke, Vrije Universiteit Amsterdam  (s.s.n.veraverbeke@vu.nl)

Robert Spencer, Florida State University  (rgspencer@magnet.fsu.edu)

Linn Speidel, ETH  (linn.speidel@erdw.ethz.ch)

Negar Haghipour, ETH  (negar.haghipour@erdw.ethz.ch)

Robert Hilton, University of Oxford   (robert.hilton@earth.ox.ac.uk)

Valier Galy, Woods Hole Oceanographic Institution  (vgaly@whoi.edu)

Matthew Jones, University of Oxford   (Matthew.W.Jones@uea.ac.uk)

Melissa Schwab, NASA JPL  (melissa.s.schwab@jpl.nasa.gov)

Timothy Eglinton, ETH  (timothy.eglinton@erdw.ethz.ch)