Glacier algae accelerate melt rates on the western Greenland Ice Sheet

Authors Organisations
  • Joseph Cook(Author)
    University of Sheffield
  • Andrew Tedstone(Author)
    University of Bristol
  • Christopher Williamson(Author)
    University of Bristol
  • Jenine McCutcheon(Author)
    University of Leeds
  • Andrew J. Hodson(Author)
    University Centre in Svalbard
    Western Norway University of Applied Sciences
  • Archana Dayal(Author)
    University of Sheffield
  • McKenzie Skiles(Author)
    University of Utah
  • Stefan Hofer(Author)
    University of Bristol
  • Robert Bryant(Author)
    University of Sheffield
  • Owen McAree(Author)
    Liverpool John Moores University
  • Andrew McGonigle(Author)
    University of Sheffield
    University of Sydney
  • Jonathan C. Ryan(Author)
    Brown University
  • Alexandre M. Anesio(Author)
  • Tristram Irvine-Fynn(Author)
  • Alun Hubbard(Author)
  • Edward Hanna(Author)
    University of Lincoln
  • Mark Flanner(Author)
    University of Michigan
  • Sathish Mayanna(Author)
    GFZ German Research Centre for Geosciences
  • Liane G. Benning(Author)
    University of Leeds
    GFZ German Research Centre for Geosciences
    Free University of Berlin
  • Dirk Van As(Author)
    Geological Survey of Denmark and Greenland
  • Marian Yallop(Author)
    University of Bristol
  • Jim McQuaid(Author)
    University of Leeds
  • Thomas Gribbin(Author)
    University of Bristol
  • Martyn Tranter(Author)
    University of Bristol
Type Article
Original languageEnglish
JournalCryosphere
DOI
Publication statusAccepted/In press - 01 Apr 2019
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Abstract

Melting of the Greenland Ice Sheet (GrIS) is the largest single contributor to eustatic sea level and is amplified by the growth of pigmented algae on the ice surface that increase solar radiation absorption. This biological albedo reducing effect and its impact upon sea level rise has not previously been quantified. Here, we combine field spectroscopy with a novel radiative transfer model, supervised classification of UAV and satellite remote sensing data and runoff modelling to calculate biologically-driven ice surface ablation and compare it to the albedo reducing effects of local mineral dust. We demonstrate that algal growth led to an additional 5.5–8.0 Gt of runoff from the western sector of the GrIS in summer 2016, representing 6–9 % of the total. Our analysis confirms the importance of the biological albedo feedback and that its omission from predictive models leads to the systematic underestimation of Greenland’s future sea level contribution, especially because both the bare ice zones available for algal colonization and the length of the active growth season are set to expand in the future