Modeling chemistry in and above snow at Summit, Greenland - Part 1: Model description and results

• Published in: Atmospheric Chemistry and Physics
• Main Authors: Thomas, Jennie L., Stutz, Jochen, Lefer, Barry, Huey, L., Gregory, Toyota, K., Dibb, Jack, E., von Glasow, Roland
• Other Authors: 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), Department of Atmospheric and Oceanic Sciences Los Angeles (AOS), University of California Los Angeles (UCLA), University of California (UC)-University of California (UC), Department of Earth and Atmospheric Sciences Houston, University of Houston, School of Earth and Atmospheric Sciences Atlanta, Georgia Institute of Technology Atlanta, Air Quality Research Division Toronto, Environment and Climate Change Canada (ECCC), Department of Earth and Space Science and Engineering York University - Toronto (ESSE), York University Toronto, Institute for the Study of Earth, Oceans, and Space Durham (EOS), University of New Hampshire (UNH), School of Environmental Sciences Norwich, University of East Anglia Norwich (UEA)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2011
• Subjects: [PHYS.PHYS.PHYS-AO-PH]Physics [physics]/Physics [physics]/Atmospheric and Oceanic Physics [physics.ao-ph]; Arctic; Greenland; Ice Sheet
• Online Access: https://hal.science/hal-00998338; https://hal.science/hal-00998338/document; https://hal.science/hal-00998338/file/acp-11-4899-2011.pdf; https://doi.org/10.5194/acp-11-4899-2011

International audience Sun-lit snow is increasingly recognized as a chemical reactor that plays an active role in uptake, transformation, and release of atmospheric trace gases. Snow is known to influence boundary layer air on a local scale, and given the large global surface coverage of snow may also be significant on regional and global scales. We present a new detailed one-dimensional snow chemistry module that has been coupled to the 1-D atmospheric boundary layer model MISTRA. The new 1-D snow module, which is dynamically coupled to the overlaying atmospheric model, includes heat transport in the snowpack, molecular diffusion, and wind pumping of gases in the interstitial air. The model includes gas phase chemical reactions both in the interstitial air and the atmosphere. Heterogeneous and multiphase chemistry on atmospheric aerosol is considered explicitly. The chemical interaction of interstitial air with snow grains is simulated assuming chemistry in a liquid-like layer (LLL) on the grain surface. The coupled model, referred to as MISTRA-SNOW, was used to investigate snow as the source of nitrogen oxides (NOx) and gas phase reactive bromine in the atmospheric boundary layer in the remote snow covered Arctic (over the Greenland ice sheet) as well as to investigate the link between halogen cycling and ozone depletion that has been observed in interstitial air. The model is validated using data taken 10 June-13 June, 2008 as part of the Greenland Summit Halogen-HOx experiment (GSHOX). The model predicts that reactions involving bromide and nitrate impurities in the surface snow can sustain atmospheric NO and BrO mixing ratios measured at Summit, Greenland during this period.