Modeled Response of Greenland Climate to the Presence of Biomass Burning-Based Absorbing Aerosols in the Atmosphere and Snow

• Main Authors: Ward, Jamie Lynn, Flanner, Mark, Bergin, Michael Howard, Courville, Zoe, Dibb, Jack E., Polashenski, Chris, Soja, Amber Jeanine, Strellis, Brandon M., Thomas, Jennie L.
• Other Authors: University of Michigan Ann Arbor, University of Michigan System, Department of Atmospheric, Oceanic, and Space Sciences Ann Arbor (AOSS), University of Michigan System-University of Michigan System, Georgia Institute of Technology Atlanta, ERDC Cold Regions Research and Engineering Laboratory (CRREL), USACE Engineer Research and Development Center (ERDC), Institute for the Study of Earth, Oceans, and Space Durham (EOS), University of New Hampshire (UNH), Dartmouth College Hanover, NASA Langley Research Center Hampton (LaRC), TROPO - LATMOS, Laboratoire Atmosphères, Milieux, Observations Spatiales (LATMOS), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)
• Format: Other/Unknown Material
• Language: English
• Published: HAL CCSD 2016
• Subjects: envir; geo; Greenland; Ice Sheet
• Online Access: https://hal-insu.archives-ouvertes.fr/insu-01423957

International audience Combustion of biomass material results in the emission of microscopic particles, some of which absorb incoming solar radiation. Including black carbon (BC), these absorbing species can affect regional climate through changes in the local column energy budgets, cloud direct and indirect effects, and atmospheric dynamical processes. The cryosphere, which consists of both snow and ice, is unusually susceptible to changes in radiation due to its characteristically high albedo. As the largest element of the cryosphere in the Northern Hemisphere, the Greenland Ice Sheet (GrIS) covers most of Greenland’s terrestrial surface and, if subjected to the increased presence of light-absorbing impurities, could experience enhanced melt. A particularly enhanced melt episode of the GrIS occurred during July 2012; at the same time, large-scale biomass burning events were observed in Eurasia and North America. Observations showed that, at the same time, single-scattering albedo (SSA) was lower than average while aerosol optical depth (AOD) was high for the Greenland region.In this study, we apply idealized climate simulations to analyze how various aspects of Greenland’s climate are affected by the enhanced presence of particulate matter in the atmospheric and on the surface of the GrIS. We employ the Community Earth System Model (CESM) with prescribed sea surface temperatures and active land and atmospheric components. Using four sets of modeling experiments, we perturb 1) only AOD, 2) only SSA, 3) mass mixing ratios of BC and dust in snow, and 4) both AOD and in-snow impurity concentrations. The chosen values for each of these modeling experiments are based on field measurements taken in 2011 (AOD, SSA) and the summers of 2012-2014 (mass mixing ratios of BC and dust). Comparing the results of these experiments provides information on how the overall climate of Greenland could be affected by large biomass burning events.